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746 Cards in this Set
- Front
- Back
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Chapter 1. What are the two relevant forms of energy in chemistry?
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1) Heat energy (movement of molecules).
2) Potential energy (energy stores in bonds). |
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Chapter 1. What does the first law of thermodynamics say?
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The first law of thermodynamics says that energy is conserved.
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Chapter 1. What does the second law of thermodynamics say? It implies that a reaction will only occur spontaneously if ______.
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The second law of thermodynamics says that the entropy of the universe tends to increase. It implies that a chemical reaction will occur only if there is an increase in disorder of the universe.
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Chapter 1. The Gibbs free energy increase with ____'ing enthalpy and decreases with _______ entropy.
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Gibbs free energy increases with increasing enthalpy and decreases with increasing entropy.
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Chapter 1. How is enthalpy defined in terms of bond energy, pressure, and volume?
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Change in enthalpy = change in bond energy-pressure (change in volume).
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Chapter 1. Does delta G increase or decrease with increasing delta S? What about increasing delta H?
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Delta G increases with increasing delta H and decreases with increasing delta S.
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Chapter 1. What is the main differences between endergonic and exergonic reactions? What about endothermic and exothermic reactions?
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Endegonic reactions require the input of energy and have a positive delta G, while exergonic reactions give off energy and have a negative delta G. In the lab, this energy is given in the form of heat.
Endothermic reactions require an input of heat while exothermic reactions give off heat. |
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Chapter 1. What is the difference between delta G standard and delta G standard with an apotrophe?
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Delta G standard is the delta G calculated with 1 M of reactants and products, while delta G standard with an apostrophe is the delta G calculated with pH = 7.0.
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Chapter 1. How is delta G standard with an apostrophe calculated? What about non standard delta G?
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Delta G standard with an apostrophe = -RTlnK(eq).
Delta G non standard = delta G standard with an apostrophe +RTlnK. |
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Chapter 1. T/F. THEORETICALLY, Given enough time, all reactant/product systems will reach a state of dynamic equilibrium?
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True.
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Chapter 1. If reactants and products have the same enthalpy but the products have more entropy, will the reaction occur spontaneously?
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Yes, b/c delta G = delta H-T(delta S), and delta H is zero, making delta G negative.
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Chapter 1. At chemical equilibrium, the ______ of the forward reactions equals the _____ of the backwards reactions.
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Rate, rate.
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Chapter 1.How can delta G be negative is delta G standard is positive?
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When the RTlnK is negative and greater in magnitude than delta G standard.
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Chapter 1. Can you tell whether products or reactants have more free energy from K? What about from Keq?
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We can tell from Keq whether products or reactants have more free energy since it tells the ratio of R and P concentrations at chemical equilibrium, which always tends towards the lowest energy state. We cannot tell the same information from K.
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Chapter 1. What are the two factors that determine whether a reaction occurs IN A CELL? What is te third factor used in the lab?
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1) Delta G standard.
2) The concentration of the products and reactants in the cell (which determines RTlnK). 3) (used in the lab) temperature. |
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Chapter 1. What does the word "spontaneous" mean in chemical thermodynamics?
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It means that a process will occur without the input of energy.
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Chapter 1. Is thermodynamics a pathway independent or pathway dependent concept?
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1) Thermodynamics = Pathway independent concept.
2) Kinetics = pathway dependent concept. |
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Chapter 1. The activation energy of a reaction is the energy needed for the reactants to reach the ________.
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Transient state (TS).
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Chapter 1. How does a catalyst lower the activation energy of a reaction?
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A catalyst lowers the activation energy by stabilizing the intermediates.
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Chapter 1. A catalyst lowers the activation energy by stabilizing the ________, making it less ________.
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TS. Less thermodynamically unfavorable.
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Chapter 1. In the body, how can a reaction with positive delta G occur?
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Reaction coupling with ATP hydrolysis.
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Chapter 1. What are two ways with which enzymes can lower the activation energy of an unfavorable reaction?
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1) Causing a conformational change in a protein.
2) Transferring a highly energetic phosphate group to a compound. |
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Chapter 1. Even though enzymes serve mainly a kinetic role in chemical reactions, can they also change the "favorability" of a reactions?
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Yes, enzymes can lower the delta G of a reaction by reaction coupling (usually in the body to the hydrolysis of ATP).
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Chapter 1. Are ALL enzymes proteins?
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No. Some enzymes are catalytic RNAs.
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Chapter 1. Suppose we have a reaction in which B and A inter-converts with each other with a Keq = [B]/[A] = 1000. If we dissolve pure A in water at 298 K, will delta G for the reaction be negative or positive?
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Negative, because we know that at the final state of dynamic equilibrium, there must be 1000 more B than A. So when there is only A present, the reaction must shift towards creating more B.
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Chapter 1. Are allosteric regulatory changes permanent? Do allosteric regulators bind covalently to the enzyme they're regulating?
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Allosteric regulators bind non-covalently and temporarily to the enzyme (NOT on the active site) they're regulating, resulting in a conformational change that either decreases or increases the rate of catalysis.
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Chapter 1. What are the two most common forms of feedback enzymatic regulation?
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1) Feedback inhibition = a crucial enzyme in a biochemical pathway is regulated by a certain intermediate in the pathway, most likely the end product.
2) Feedforward stimulation = the enzyme in a biochemical pathway is stimulated by an intermediate in the pathway (usually the first intermediate). |
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Chapter 1. The phenomenon of cooperativity is seen mainly in what type of enzymes (single unit or multi-unit enzymes?)
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Cooperativity is seen mostly in enzymes with multiple subunits with multiple active sites (this is REQUIRED), which can either be seen as a single enzymatic unit with multiple actives sites or multiple subunits, each with its active site, linked together.
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Chapter 1. What are four ways that the activity of an enzyme can be regulated?
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1) Covalent modification.
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Chapter 1. What are the four ways that the activity of an enzyme can be regulated?
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1) Covalent modification.
2) Allosteric regulation. 3) Proteolytic cleavage. 4) Association with other polypeptides (some enzymes have regulatory subunits, and elimination of this subunits turns on the enzyme forever.) |
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Chapter 1. What are the two main ways that cooperative enzymes are regulated?
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1) Binding of activating/deactivating molecules.
2) Allosteric regulation. |
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Chapter 1. What is the ideal shape for a competitive inhibitor of an enzyme? What must it resemble to maximize inhibition?
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The competitive inhibitor must resemble the the TS.
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Chapter 1. How can one tell the difference between cooperativity and non-cooperativity with rate of reaction data?
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Look at the difference in reaction rates starting with very little substrate present. If the increase in reaction rate with increasing substrate is NOT linear, then the enzyme is exhibiting cooperativity.
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Chapter 1. Where do non-competitive inhibitors bind to an enzyme? Are they
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Non-competitive inhibitors bind allosterically to an enzyme, and they do change the Vmax.
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Chapter 1. What are the three ways you can oxidize and reduce an atom?
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Oxidize:
1) Attach oxygen (or at least increase the number of bonds to oxygen). 2) Remove hydrogen. 3) Remove electrons. Reduce: 1) Remove oxygen (or remove bonds to oxygen). 2) Add hydrogen. 3) Add electrons. |
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Chapter 1. When you reduce something, you increase/decrease the potential energy of the compound.
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When you reduce something, you increase the potential energy of the compound. The reduced compound wants to be oxidized back to what it originally was.
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Chapter 1. The catabolism of glucose is an oxidative / reductive process and is paired with what process?
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The catabolism of glucose if an oxidative process and is a favorable process coupled with the unfavorable synthesis of ATP from ADP and Pi.
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Chapter 1. What four steps are involved inthe oxidative catabolism of glucose?
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1) Glycolysis.
2) PHC. 3) Krebs Cycle. 4) Oxidative phosphorylation. |
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Chapter 1. How is the energy within glucose transferred to those needed to make ATP?
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Glucose is oxidized---> Energy released from oxidation is transferred to high energy electron carriers--> Energy from these electron carriers are transferred to the electron transport chain to pump out protons, which form a gradient with enough potential energy to make the ATPs.
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Chapter 1. Where does glycolysis occur in the cell? How is pyruvate changed into acetyl Co-A in preparation for entry into the Krebs Cycle?
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The cytosol. Each pyruvate made from glucose is decoboxylated and attached to co-enzyme A to form acetyl Co-A, which enters the Krebs CYcle.
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Chapter 1. Is oxygen required for stages II, III, and IV in the oxidative catabolism of glucose?
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Yes, but not directly.
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Chapter 1. Are NADH and ATP produced in glycolysis and the PDC complex?
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Only NADH is formed in the PDC complex. NADH and ATP are both formed in glycolysis.
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Chapter 1. In glycolysis, for each glucose molecule, _____ ATPs are inputted, ___ ATPs are obtained, giving a net _____ ATPs. Also, _____ NADHs are formed.
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-Per glucose: 2 ATPs are inputted, 4 are generated, giving 3 net ATPs. 2 NADHs are formed.
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Chapter 1. What is the name of the first enzyme of glycolysis, which phosphorylates glucose on 6th carbon? and is in turn inhibited by the buildup of this product?
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Hexokinase.
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Chapter 1. NADH is produced in only one step. This step usually involves an aldehyde turning into another functional group. What is this functional group?
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-COOH.
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Chapter 1. What important compound is usually formed when a phosphate group comes off a compound in biochemistry?
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ATP.
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Chapter 1. What is the importance of PFK enzyme. What step of the oxidative pathway does it work? What is it allosterically inhibited by?
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PFK works by transferring a phosphate group from ATP to fructose-6-phosphate, giving fructose-1,6-biphosphate. This is an early step is glycolysis and is a highly favorable step, and thus must be regulated. PFK is allosterically inhibited by ATP.
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Chapter 1. Will a lack of NAD+ inhibit or stimulate glycolysis?
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A lack of NAD+ will inhibit glycolysis, because it needs NAD+ as raw material to make NADH.
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Chapter 1. In the absence of oxygen as the final electron acceptor, NAD+ can no longer be regenerated. How have organisms adapted to this? What are two examples of this?
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Anaerobic organisms have evolved to use fermentation to regenerate NAD+ for glycolysis. In this process, the pyruvate becomes the final electron acceptor. Two examples are ethanol production from alcoholic fermentation and lactate fermentation.
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Chapter 1. Is there a limit on the extent to which organisms use fermentation as an energy source? Why?
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Yes. The products of fermentation are poisonous at high concentrations.
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Chapter 1. What is the importance of the pyruvate dehydrogenase complex in terms of the overall process of oxidative glucose catabolism?
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The PDC basically converts the pyruvate into an activated acetyl group (attached to a high energy sulfur bond). The Co-A group is used to shuttle the acetyl group around in the PDC and the high energy sulfur bond makes it easier for further oxidation in the Krebs Cycle.
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Chapter 1. Is the PDC regulated by?
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Yes, it is very important to regulate the PDC unit. AMP is one of several compounds that can regulate the complex.
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Chapter 1. What is the difference between an enzyme co-factor and prosthetic group?
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Prosthetic groups are non-protein molecules COVALENTLY bound to an enzyme as part of the enzyme's ACTIVE SITE.
Co-factors are various organic and non organic substances necessary for the functioning of the enzyme but never interacts with the enzyme. |
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Chapter 1. Beriberi metabolic disorder that results from a deficiency of thiamin. Would the rate of glcolysis increase or decrease in patients with this disorder?
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Increase, since for these patients glycolysis would be the primary means of extracting energy from glucose, as the thiamin deficiency would preclude the functioning of various enzymes needed in the Krebs Cycle and PDC (thiamin is part of a prosthetic group in TPP in the PDC).
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Chapter 1. Would the lack of NAD+ stop the reactions of the Krebs Cycle and PDC complex?
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Yes.
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Chapter 1. Where do all the carbon atoms in the carbohydrates we consume eventually end up.
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CO2, which results from the decarboxylation of the organic compound either during the Krebs Cycle or from the PDC.
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Chapter 1. What process is paired with a decarboxylation in the Krebs Cycle?
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The reduction of NAD+ to NADH. Decarboxylations are oxidative processes.
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Chapter 1. The inter-membrane space in the mitochondrion is/is not continuous with the cytosol. Why or why not?
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The inter-membrane space is continuous with the cytosol because the outer mitochondrion membrane has large pores formed by porin proteins, which allow the contents of the cytosol to mix with that of the intermembrane space.
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Chapter 1. Are ALL the high energy electron carriers located in the mitochondria?
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No. The NADH created in glycolysis are located in the cytosol and would have to be transported into the mitochondrion in order to pass its electrons to the ETC.
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Chapter 1. Why do prokaryotes produce two extra ATP per glucose from oxidative phosphorylation?
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Prokaryotes produce two extra ATPs per glucose from oxidative phosphorylation because they do not have to transport the NADHs produced in glycolysis into the mitochondrion, as eukaryotes do.
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Chapter 1. Why is it better to have all the enzymes necessary for a single process located in a "super complex" rather than scattered throughout the cell?
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No need for the intermediates from one enzyme to diffuse to the next.
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Chapter 1. Where are all the protons pumped during the final stage of oxidative phosphorylation?
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The intermembrane space.
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Chapter 1. DNP is a powerful uncoupler for oxidative phosphorylation. What is the first process that is inhibited following the ingestion of this compound? A, pyruvate decarboxylation by the PDC. B, the TCA cycle. C, electron transport. D, muscle contraction.
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D.
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Chapter 1. How many protons approximately are required to be pumped for the formation of one ATP? From this information we can infer that one NADH can form ____ ATP, and one FADH2 can form ____ ATPs.
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About 4. Each NADH (can pump 10 protons) can make 2.5 ATPs, and each FADH2 (can pump 6 protons) can make 1.5 protons.
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Chapter 1. What is the pathway with which eukaryotes use to shuttle the cytosolic NADHs into the ETC? Where do the electrons from cytosolic NAHD enter the ETC?
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Glycerol phosphate shuttle. Through this pathway, the electrons from cytosolic NADH are shuttled to UB rather than complex I, thus pumping only 6 protons and produces only 1.5 ATPs.
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Chapter 1. How many NADHs are made per glucose from the PDC?
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2 NADHs are made from the PDC per glucose.
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Chapter 1. What are the main products of the TCA cycle and how many of each product is formed per glucose?
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Per glucose molecule, the TCA cycle produces 6 NADHs, 2 FADH2s, and 2 GTPs.
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Chapter 2. What are the three main components of dNTPs?
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1) An aromatic base.
2) A ribose sugar. 3) Phosphate group. |
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Chapter 2. What is the main structural difference between the building blocks of RNA and DNA?
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The DNA has no oxygen bound to C2 in its ribose ring.
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Chapter 2. Why are the aromatic molecules in the DNA and RNA bases? Which aromatic bases are considered pyrimidines and which ones are considered purines?
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The aromatic molecules in DNA and RNA are bases because they contain electrons which allow the acceptance of protons.
G and A are considered purines and T and C are considered pyrimidines. |
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Chapter 2. What is the difference between a nucleoside and nucleotide?
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A nucleotide is the phosphate ester of a nucleoside.
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Chapter 2. In diulte solutions will the T and A hydrogen bond to each other?
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No, in dilute solutions the T and A will H bond with water.
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Chapter 2. Where is the H bonding potential the largest in a DNA molecule?
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Between the aromatic bases.
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Chapter 2. How many phosphate groups can a nucleotide have joined to its ribose ring?
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Up to three.
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Chapter 2. What is considered the backbone of the DNA molecule? What would an enzyme that interacts with DNA bind to? the backbone or the bases?
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The ribose and phosphate portion of the nucleotide are the backbone of DNA.
The enzyme would bind to the variable bases, since the enzyme interacts specifically with a sequence of DNA. |
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Chapter 2. Which reaction is more thermodynamically favored? the polymerization of nucleoside monophosphates or the polymerization of nucleoside triphosphates?
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The polymerization of nucleoside trophosphates is more thermodynamically favored because it creates a pyrophosphate group, which dissociates into 2 Pi's very spontaneously.
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Chapter 2. Through which kinds of bonds are the building blocks of DNA held together?
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Phosphodiester bonds.
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Chapter 2. How many h bonds are needed to hold the G to the C in DNA? What about the A and T? Do both bonds take up the same or different amount of room in the DNA molecule?
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-G and C require 3 H bonds and A and T require 2 h bonds. Both bonds take up the same amount of room in the DNA molecule.
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Chapter 2. Can a pyrimidine ever H bond with a purine in DNA?
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No.
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Chapter 2. What does T (sub m) stand for?
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T sub m stands for the temperature needed to melt 50% of DNA molecules in solution.
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Chapter 2. What two types of interactions are responsible for stabilizing the double helix nature of the DNA molecule?
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1) Hydrophobic interactions between the bases.
2) Van der Waal interactions between the bases. |
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Chapter 2. How is it possible that the aromatic bases in DNA can have hydrophobic interactions (which are necessary to stabilized the double helix of the DNA molecule)?
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Once a purine H bonds to a pyrimidine, the individual polarity of the base disappears as the charged dipoles are occupied in the h bonds.
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Chapter 2. The width of the DNA molecule is always ____ angstroms. What about the distance between two bases in the DNA? The helix pattern repeats itself once in every ______ base pairs, which is about ____ angstroms.
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The width of DNA is always 20 angstroms. The bases are 3.4 angstroms apart on the DNA molecule. The helix repeats itself one every 10 base pairs, or 34 angstroms.
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Chapter 2. Prokaryotic genomes are organized as ______, what about for viral genomes?
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Prokaryotic genomes are seen as one circular chromosome, viral genomes can be line or circular DNA or RNA.
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Chapter 2. How do prokaryotes condense their genetic material to facilitate packaging? What about eukaryotes?
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Prokaryotes use DNA gyrase to supercoil their DNA into a denser structure.
Eukaryotes package their DNA in various stages. The first stage uses histones, with DNA wrapped in groups of 8 histones, forming a nucleosome. The DNA that joins each nucleosome is called linker DNA. the nucleosomes are then packed together to form an even denser structure called chromatin in the final stage. |
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Chapter 2. Are histones mostly basic or acidic?
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Histones are usually basic.
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Chapter 2. What are the three main types of mutations
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1) Point mutations.
2) Insertions mutations. 3) Deletion mutations. |
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Chapter 2. Point mutations can be _____'ns (in which ________) or ________'ns (in which ________. What are the three main types of point mutations?
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Point mutations can either be transitions (in which a pyrimidine is substituted for another pyrimidine and same for purines) or transversions (in which a purine is substituted for a pyrimidine and vice versa).
Three types of point mutations are: 1) Missense mutation = a amino acid is changed to another AA. 2) Nonsense mutation = a stop codon is made prematurely. 3) Silent mutations = the point mutation does not change the identity of the AA. |
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Chapter 2. What is defined as a conservative mutation?
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A conservative mutation is a mis-sense mutation that changes the identity of the amino acid chain (primary structure) but does not change the overall structure of the protein (secondary, tertiary, and quaternary structures).
An example would be a mis-sense mutation that involves changing a small hydrophobic AA with another small, hydrophobic AA. |
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Chapter 2. DNA helicase works at very specific locations on the DNA molecule. What are these regions called?
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Origins or replication.
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Chapter 2. Look at the example question on page 58 of the MCAT biological review.
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LOOK.
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Chapter 2. What enzyme is used to relive the strain produced at the regions of DNA upstream and downstream of the origin of replication when DNA helicase unwinds DNA?
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DNA topoisomerases are used to relieve the strain produced when DNA hlicase works.
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Chapter 2. Do DNA grase and DNA topoisomerase perform similar or opposite functions?
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Opposite.
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Chapter 2. What are used to stabilize the single stranded DNA molecules after DNA helicase has worked?
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Single stranded binding proteins.
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Chapter 2. How many replication bubbles do eukaryotes have? What about prokaryotes?
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Eukaryotes have multiple replication bubbles, while prokaryotes only have one.
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Chapter 2. DNA polymerase III has 5'--> 3' DNA polymerization activity as well as ________ activity for correction.
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3' --> 5' exo-nuclease activity.
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Chapter 2. What is the function of prokaryotic DNA polymerase II?
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-Prokaryotic DNA polymerase II = no known function.
-Prokaryotic DNA polymerase I = has 5' --> 3' DNA exonuclease activity to remove RNA primers and replace with DNA, which it accomplishes with its 5' -- 3' DNA polymerase activity. It also has a 3' --> 5' exonuclease activity, like DNA polymerase III. |
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Chapter 2. What are three ways with which RNA is chemically distinct from DNA? What makes RNA less stable than DNA?
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1) RNA is singles tranded.
2) RNA has uracil instead of thymine. 3) The pentose ring in RNA is ribose rather than 2' deoxyribose. RNA is less stable than DNA because the OH group on the 2' carbon of the pentose ring can attach the the phosphate group of the next nucleotide and cause the RNA chain to break. |
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Chapter 2. What is the difference between monocistronic and polycistronic mRNA? Which one is seen in prokaryotes?
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Monocistronic mRNA are mRNA segments that only code for one protein. This is seen in eukaryotes.
Polycistronic mRNA are mRNA segments that can code for more than one protein. This is seen in prokaryotes. |
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Chapter 2. Why would anti-cancer drugs dealing with nucleic acids target thymine production?
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Anti-cancer drugs target thymine production because thymine is the only nucleotide that's needed in DNA replication and does not affect RNA. Thus, it can target rapidly dividing cells (most likely cancer cells) by destroying one of its crucial components needed for the S phase that precedes mitosis.
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Chapter 2. What is the importance of rRNA?
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rRNAs provide the catalytic function of ribosomes as well as some enzymatic RNAs. They are also one of the structural components of ribosomes.
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Chapter 2. Is DNA transcription a process with high or low accuracy? What serves as the driving force for this process? Does ti require a primer?
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Low accuracy, because RNA polymerase has no proofreading activity.
The driving force of DNA transcription is the removal and hydrolysis of pyrophosphates following the addition of each nucleotide to the growing RNA chain. No, DNA transcription does not require a primer. |
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Chapter 2. Is the place where transcription starts the same as the place on the DNA that activates RNA polymerase?
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No. The place where transcription starts is called the start site and the promoter.
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Chapter 2. Where is the major site of regulation for gene expression?
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Transcription.
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Chapter 2. The strand of DNA that is actually transcribed is called the sense/anti-sense, coding/non-coding strand?
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Antisense, non-coding. It sequence is complementary to the transcript.
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Chapter 2. When locations are given relative to the start site of transcription, are they given in terms of the coding or non-coding strand.
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Coding.
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Chapter 2. What is the holoenzyme on a bacterial RNA polymerase? What is its function?
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The holoenzyme is a particular subunit, called a sigma factor, on the bacterial RNA polymerase that scans the DNA until it finds a promoter. Once the promoter site is found, the holoenzyme stays bound to it, forming a closed complex. Once the RNA unwinds the DNA, transcription can begin and the complex is called the open complex.
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Chapter 2. The sigma factor of the bacterial RNA polymerase plays two factors:
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1) To help the RNA polymerase recognize the promoter.
2) To decrease RNA polymerases no specific affinity to DNA. |
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Chapter 2. What is the main advantage of turning off genes whose protein product are not required (assuming excess protein products ar not toxic)?
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The saving of energy (ATPs).
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Chapter 2. Catabolic enzymes are usually repressible or inducible? what about anabolic enzymes? What are the default states of each?
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Anabolic enzymes are usually repressible and catabolic enzymes are usually inducible. Catabolic enzymes are usually off in the default state while anabolic enzymes are on.
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Chapter 2. A bacterial operon has three main components, what are they?
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1) Coding region.
2) Upstream regulatory region. 3) Gene encoding regulatory protein. |
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Chapter 2. What are the 4 main differences between eukaryotic and prokaryotic transcription?
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1) The location of transcription.
2) The primary transcript and mRNA. 3) The RNA polymerases. 4) Regulation of transcription. |
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Chapter 2. Do translation and transcription occur simultaneously in in eukaryotes? What about in prokaryotes?
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Translation and transcription occur simultaneously in prokaryotes only. Eukaryotes must transcribe their DNA and modify it in the nucleus, then transport it across the nuclear membrane where it can be translated.
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Chapter 2. In prokaryotes, all the transcription is performed by one enzyme, which is _____. This is not so in eukayotes. What are the three functions of eukaryotic RNA polymerase I, II, and III?
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Prokaryotic transcription enzyme = fasdfjisoadjfo.
I. = transcribes rRNA. II. = transcribes mRNA. III. = transcribes tRNA. |
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Chapter 2. What are the three post transcriptional modifications made in eukaryotes? What is the purpose of each?
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1) Splicing.
2) Addition of 5' cap. 3) Polyadenylation. 2) and 3) occur to prevent mRNA from enzymatic digestion. The 5' cap is essential to translation. |
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Chapter 2. The promoter region of eukaryotic transcription has a special name, which is _____.
Can transcription factors increase as well as decrease rate or transcription? Other than sequences that bind to TF regions, what is another sequence of DNA that may serve to activate transcription? |
TATA box. Yes. Enhancers.
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Chapter 2. If a mutation in a fat cell reduces the the level of several proteins related to fat metabolism, does that mean that all the proteins are coded by the same mRNA?
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No! Eukaryotic genes are monocistronic! One possibility is that the mutation occurs for the gene of a sequence specific transcription factor, which are responsible for regulating the production of these proteins.
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Chapter 2. What is the purpose of exonucleases in the cell?
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To break down old and useless mRNA and to destroy foreign DNA.
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Chapter 2. How is the unfavorable process of amino acid activation (attaching AAs to tRNAs) and peptide bond formation driven forward in translation?
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Reaction coupling. The AA is attached to AMP for form aminoacyl AMP, which gives off pyrophosphate as a side product, driving the reaction forward.
The tRNA loading (attaching AA to tRNA) is driven forward by the destruction of the high energy amino-acyl-AMP bond. The bond between the tRNA and AA i used to drive the peptide bond formation. |
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Chapter 2. How is the specificity of each amino acid attaching to the correct tRNA achieved?
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This specificity is achieved by having at least one enzyme for each tRNA-AA pair.
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Chapter 2. What are the two purposes of activating an AA?
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1) To join it to its corresponding tRNA.
2) To drive the unfavorable process of peptide bond formation. |
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Chapter 2. The complete ribosomal structure has how many sites? What are these sites called?
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3. The A, P, and E sites.
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Chapter 2. Prokaryotic ribosomes are called _____S ribosomes, while eukaryotic ribosomes are called _____S ribosomes.
What are the two subunits called for the eukaryotic and prokaryotic ribosomes? |
Eukaryotic ribosomes are called 80S ribosome, which is made of the 60S and 40S subunits).
Prokaryotic ribosomes are called 70S ribosomes, which are made of the 50S and 30S subunits. |
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Chapter 2. Are polyribisomes found in both eukaryotes and prokaryotes?
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Yes.
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Chapter 2. The bacterial regulatory site for that is essential for the initiation for translation upstream of the start site is called the _______. This is also known as the ribosome binding site.
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Shine-Delgarno sequence.
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Chapter 2. How many ATP equivalents are used in activating an amino acid?
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2, because 2 high energy phosphate bonds are broken in the hydrolysis of ATP to AMP.
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Chapter 2. What drives the unfavorable process of peptide bond formation in protein synthesis?
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The breaking of the bond between AA and the tRNA of the PREVIOUS AA tRNA pair in the polypeptide chain.
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Chapter 2. What must happen before an AA is activated (attached to its corresponding tRNA)?
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Attachment of the AA to AMP.
-The hydrolysis of pyrophosphate drives the reaction forward. |
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Chapter 2. In protein synthesis, the polypeptide is always synthesized from the N/C terminus to the N/C terminus.
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The polypeptide is always synthesized from the N --> C terminus.
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Chapter 2. The formation of the 70S initiation complex for prokaryotic translation requires the expenditure of ____ GTP? The initiator tRNA is special because it carries the AA ______. The initial tRNA sit in the A/P/E site on the prokaryotic ribisome?
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-1.
-f-Methionine. -P site. |
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Chapter 2. During the translocation step of elongation in protein synthesis, does the mRNA move relative to the ribosome or the other way around?
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The ribosome moves relative to the mRNA.
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Chapter 2. During prokaryotic protein synthesis, how is termination achieved?
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When the stop codon is encountered, a release factor enters the A site and the peptidyl transferase cuts the bond between the bond between the last tRNA and the completed polypeptide.
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Chapter 2. At which steps in prokaryotic protein synthesis are GTPs used?
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1) In the activation of the AA (2 ATP equivalents used per AA).
2) 2 phosphate bonds are needed for each elongation step (number of elongations needed is the number of AAs in polypeptide chain -1) 3) 1 GTP needed to stabilize the initiator tRNA onto the ribosome. |
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Chapter 2. T/F. fMet is the starting AA in ONLY prokaryotic (not eukaryotic) polypeptide chains.
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True.
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Chapter 2. What is the difference in which the components of the initiation complex for translation are put together in eukaryotes and prokaryotes?
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In eukaryotes, the first tRNA binds to the small subunit, followed by the mRNA, and only after this does the large ribosomal subunit subunit bind to the small ribosomal subunit.
In prokaryotes, the mRNA and first tRNA bind to the smaller ribosomal subunit simultaneously. |
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Chapter 2. Is it possible to have transcription and spicing at the same time?
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Yes. In the transcription of larger genes, the introns are spliced out during transcription.
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Chapter 2. Are all the newly formed polypeptides emerging from a ribosome translating one piece of mRNA the same for all eukaryotes? What about for prokaryotes?
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Yes. For prokaryotes this is not the case as prokaryotic mRNA is polycistronic and multiple proteins can be made from the same mRNA.
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Chapter 4. What is the function of the peroxisome in the cell? What about the smooth ER?
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Peroxisomes metabolize lipids and toxins using H2O2.
The smooth ER detoxifies and is responsible for glycogen breakdown in the liver. It is also involved in steroid synthesis in gonads. |
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Chapter 4. True or false, ALL components of the eukaryotic ribosome are made in the cytosol.
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False. Part of the eukaryotic ribosome is assembled in the nucleus.
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Chapter 4. Where does translation occur in eukaryotes? If an enzyme that breaks down mRNA is injected into a cell's cytosol and all translation ceases, is this a prokaryotic or eukaryotic cell?
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The cytosol.
The cell could be either. |
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Chapter 4. What special problems are encountered in replicating the 5' ends of a linear chromosome?
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At the very ends of the 5' linear chromosome. The DNA polymerase will replicate the DNA from an RNA primer at or near the end of the chromosome, but the RNA primer cannot be replaced with DNA.
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Chapter 4. What is the difference between heterochromatin and euchromatin?
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Heterochromatin is the region of the genome that is densely packed, and genes residing in this region are most likely turned off.
Euchromatin is a region of the genome where the chromatin is not densely packed and the genes here are readily accessible. |
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Chapter 4. What are the main roles of the nuclear scaffold or matrix?
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1) Structural support for the nucleus.
2) Regulating gene expression (area of ongoing research). |
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Chapter 4. What role do the loops of DNA in the nucleolus play? What happens in the nucleolus?
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The loops of DNA serve as templates for the transcription of rRNA by RNA polymerase I.
The transcription of tRNA happens in the nucleus. |
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Chapter 4. The space between the inner and outer nuclear membrane is continguous with the _____ of the ER.
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Lumen.
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Chapter 4. The nuclear membrane has large spaces created by ____ proteins that allows diffusion of molecules smaller than ____ kDa. Molecules larger than this must have a ______ to pass through.
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Porin. 60. NLS.
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Chapter 4. There are two sites of protein translation in the cell, where are they? There is only place where translation starts, where? What is an SRP particle?
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Translation always starts in the cytosol, and depending on whether the protein sequences contains a signal sequence, an SRP particle will bind to the ribosome, halting translation, and the SRP-ribosomal complex docks onto the rough ER, where translation finishes.
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Chapter 4. Proteins translated in the cytosol are bound for ______ in the cell, what about proteins translated in the rough ER?
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Proteins translated in the rough ER are destined for extracellular environment, to become integral membrane proteins, or in the membrane of the lysosome, ER, or Golgi apparatus.
Proteins translated in the cytosol are destined for the mitochondria, nucleus, or remains in the cytosol. |
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Chapter 4. Where do the most translational modifications of proteins occur in the cell?
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In the lumen of the rough ER.
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Chapter 4. For an integral protein on the plasma protein, does the portion of the protein that sticks out of the cell belong in the lumen of the ER of outside the ER?
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Lumen of the ER.
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Chapter 4. Can a protein ever make it out of the cell without going through the trans golgi?
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No. The trans golgi is the site where the sorting of proteins to different vesicles is determined.
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Chapter 4. What is the difference between the constitutive secretory pathway vs the regulated secretory pathway?
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In the constitutive secretory pathway, the vesicles leave the golgi and immediately go to the cell surface. In regulated secretory pathway, the proteins in the vesicles are not released until certain times.
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Chapter 4. What are the three types of "-phagy" seen in lysosomes?
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1) Autophagy-dysfunctional organelles are degraded by lysosomes.
2) Phagocytosis-large particulate matter engulfed by the cell via phagocytosis are sent to a phagocytotic vesicle, which are fused to lysosomes. 3) Crinophagy-lysosomal digestion of unnecessary secretory products. |
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Chapter 4. Can hydrogen bonds anchor peripheral proteins to the cell plasma membrane?
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Yes, in addition to electrostatic forces.
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Chapter 4. What two factors play a major role in membrane fluidity?
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Saturation of the fatty acids of the phospholipids in the membrane and cholesterol.
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Chapter 4. What is the primary driving force for diffusion? Why do substances always want to go from a high concentration to low concentration?
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Entropy and the second law of thermodynamics. Diffusing from a high to low concentration maximizes entropy.
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Chapter 4. Osmosis involves the diffusion of the solvent or solute? What must it always have to ensure that this type of diffusion occurs?
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Osmosis involves the diffusion of the solvent and must always have membrane permeable only to the solvent.
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Chapter 4. What is the difference between a hypotonic vs hypertonic solution?
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A hypotonic solution will have a higher concentration of dissolved solutes than the cell. A hypertonic solution has less concentration of dissolved solutes than the cell.
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Chapter 4. The magnitude of osmotic pressure in terms of tonicity is determined by ______.
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The difference in tonicity in both sides of the semi-permeable membrane. The larger the difference, the larger the osmotic pressure.
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Chapter 4. As more and more solute is added, does the rate of facilitated diffusion through a membrane increase forever?
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No. The kinetics of facilitated diffusion follows saturation kinetics, just like enzymes.
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Chapter 4. What are the two types of active transport?
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Primary active transport, in which the energy of ATP hydrolysis is coupled to the thermodynamically unfavorable process of transport.
Secondary transport-a thermodynamically unfavorable transport process is coupled to a favorable process. |
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Chapter 4. What are the three purposes of having the Na+/K+ pump?
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1) To maintain osmotic balance in the cell.
2) To establish the resting membrane potential. 3) To provide sodium concentration gradient which is used to drive secondary active transport processes. |
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Chapter 4. What's the point of a high concentration of extracellular Cl- concentration?
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To maintain a balanced charge on inside and outside of the cell. The cell has many negatively charged macromolecules inside. Thus, it needs some negative charges outside as well.
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Chapter 4. What are the three types of endocytosis in eukaryotic cells?
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1) Pinocytosis.
2) Phagecytosis. 3) Receptor mediated endocytosis. |
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Chapter 4. There are three types signal transduction related receptors, what are they?
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1) G-protein linked receptors.
2) Catalytic receptors (RTK). 3) Ligand gated ion channels-receptor becomes an ion channel upon binding to the ligand. |
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Chapter 4. Are centrioles essential for mitosis?
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No. Mitosis in plants can still occur without centrioles. Also, experimenters have been able to remove centrioles from animal cells and these cells can still undergo mitosis.
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Chapter 4.Cilia and flagella have the same basic structure, which include a ___+___ arrangement of MTs, with each MT bound to its neighbor by a contractile protein called ______. The cilium or flagellum is anchored to the cell via _____, which has the same structure as the ______.
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9+2.
Dynein. Basal body. Centrioles. |
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Chapter 4. A cell's cytoskeleon provides ______. It also allows the cell to _____ and the _____ within the cell.
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Structural support.
Move. Internal transport of materials within the cell. |
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Chapter 4. What are two main differences between intermediate filaments and MTs and microfilaments?
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Intermediate filaments are more permanent and are more heterogeneous.
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Chapter 4. What are the main functions of IFs, MTs and microfilaments?
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-All three contribute to the cell's structure.
-IFs: to provide resistance against mechanical stress for the cell. -Microfilaments: Division of the cell itself during mitosis or meosis. Movement of the cell (amoeba). -MTs-movement of chromosomes during mitosis and meosis, movement of materials across nerve axons, and movement of the cell (cilia and flagella).What |
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Chapter 4. Can MTs polymerize from both ends? Why or why not?
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MTs can only polymerize from one end because the other end is attached to the MTOC (MT organizing center).
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Chapter 4. What are the three types of cell junctions?
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1) Tight junctions-permits no passage of materials across the layer of linked cells.
2) Gap junctions-permits free passage of ions within the cytoplasms the cells that are linked. This is seem commonly in smooth muscle and cardiac muscle. 3) Adhering junctions- |
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Chapter 4. Do desmosomes provide cells a tight seal (no materials can pass through)?
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No. Desmosomes merely hold cells together. They do not provide a tight seal, and they do not band around the entire cell.
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Chapter 4. How are desmosomes anchored to the cell?
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The desmosomes are attached to the plasma membrane by a plaque for by protein called keratin. Then, intermediate filaments of the cytoplams attach to the inside of the desmosome. Desmosomes are not free to diffuse across the memrbrane.
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Chapter 4. At what phase in the mitotic cycle is a karyotype made?
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Metaphase. At this stage, the cells are frozen, chromosomes are stained, and pictures are taken.
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Chapter 5. Is it possible for a person to have more than two alleles for a specific gene?
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No, even though there may be more than two POSSIBLE alleles for any gene, any one person can only have two of the alleles with the exception of those who are polyploid.
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Chapter 5. What is the difference between co-dominance and incomplete dominance?
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Co-dominance means that when a heterozygote inherits both dominant alleles, the phenotypes of both alleles are expressed (e.g. AB blodo type) and not simply blended together (pink flower color for red and white flower alleles).
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Chapter 5. What is the definition of pleiotropism?
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Pleiotropism describes the phenomenon in which alteration of a gene affects many different, seemingly unrelated aspects of an organism's total phenotype.
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Chapter 5. What is the definition of genetic penetrance?
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Penetrance describes the probability that a person with a certain genotype will express the phenotype.
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Chapter 5. What is the definition of epistasis?
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Epistasis describes the situation where the expression for alleles of one gene is dependent on a different gene. An example is a gene for curly hair cannot be expressed if a different gene causes baldness.
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Chapter 5. When does the cell become haploid from diploid during meosis? At what stage of meosis does crossing over occur? What is the point of the second phase of meosis?
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After anaphase I of meosis, the cell becomes haploid. Crossing over occurs during prophase I. The point of the second phase of meosis is to separate the sister chromatids of each replicated chromosome so that daughter cells contain non-replicated chromosomes.
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Chapter 5. Are the four cells made from meosis identical genetically? Why or why not?
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No. They would be if crossing over had not occurred.
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Chapter 5. How many copies of a chromosome will each gamete have? What about when nondisjunction occurs during meosis I and homologous chromosomes fails to separate? What about non disjunction during meosis II?
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Each gamete should have only one copy of each chromosome.
If non disjunction occurs during meosis I, then one cell could have four copies of a chromosomes and the other will have non. If non-disjunction occurs during meosis II, then two cells will have two copies of a chromosome and two cells will have none. |
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Chapter 5. What is the result when a gamete resulting from non-disjunction fuses with another normal gamete?
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Monosomy or trisomy.
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Chapter 5. During meosis I, do the parental chromosomes always separate together?
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No.
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Chapter 5. What do the laws of independent assortment and segregation say?
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The law of independent assortment says that alleles of one gene will separate independently of another alleles of another gene.
The law of segregation says that two alleles from one individual are separated singly from one generation to the next. |
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Chapter 5. If the height gene (T/t) and color gene are close to each other on a chromosome (linkage), can one tell the possible gametes of a TTgg individual? What about a TtGg individual? How would a punnett square be designed for these types of crosses?
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TTgg individual: Yes, bet.ause there is only one possible gamete, Tg, regardless of whether there is linkage or no,
TtGg individual: No, because (refer to page 177 of biological review) you never know which alleles is on which chromosome. A punnett square can be designed by putting the paired alleles on the outside of the box rather than one allele on the outside of the box. |
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Chapter 5. What will allow alleles located on the same chromosome to separate independently?
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Crossing over.
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Chapter 5. How do you calculate a recombinant frequency? What is the R.F. proportional to?
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A recombinant phenotype arises when gens for two traits are linked and a phenotype arises from a cross that could only result if the the genes were independently assorted.
R.F. = number of recombinant offspring/total number of offspring. The R.F. is proportional to the distance between the linked genes on the chromosome. |
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Chapter 5. If there is genetic linkage between two genes, and you have a heterzygote, how would you proceed to find out how the genes are linked (remember there are two possible combinations and there can only be one of the two)
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Look at the genotypes of the parents.
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Chapter 5. What is the maximum frequency of recombination?
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Maximum recombination occurs when there is so much recombination that the genes don't even seem to be linked on the same chromosome. Thus, the maximum frequency of recombination would be calculated as the frequency of recombinant phenotype you would expect without any genetic linkage.
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Chapter 5. Is it possible to map linked genes on the same chromosome if they are so far apart that the genes seem to assort independently?
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Yes, but only if there is at least a gene in between the two on the chromosome.
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Chapter 5. Can males ever receive their X chromosome from their mothers?
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No.
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Chapter 5. Is it possible for males to be carriers of a recessive y linked trait?
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No.
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Chapter 5. How do you spot the recombinant phenotype from experimental data in which the number of offspring with each phenotype is given from a cross?
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The recombinant phenotypes are usually that occur much less than other phenotypes.
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Chapter 5. When you perform a cross involving two genes that are on the same chromosome, would you see results that show 100 percent linkage between the two genes?
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No, the results often show an intermediate between 100% linkage and complete independent assortment.
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Chapter 5. What are the five steps that you always want to utilize when studying pedigrees?
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1) Determine whether the gene causing the disease is dominant or recessive.
2) and 3) Is the gene for disease sex linked? If so, is it linked on the X or Y chromosome? 4) Figure out genotypes and calculate probabilities of inheritance where necessary. 5) If two traits are involved, go back to steps 1-4 for the other trait. |
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Chapter 5. When you are calculating the chances that an individual will inherit a sex linked trait, what additional probability much be factored in with the chance that the individual will get the disease from his/her parent from the punnett square?
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The probability of the individual being the gender that the trait shows up in.
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Chapter 5. What is one strict requirement for a group of organisms to be a population?
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The individuals must be able to sexually reproduce with one another.
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Chapter 5. Hardy Weinberg population genetics assumes what will never change over time? What are the assumptions that this statement rests on?
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HH population genetics assumes that the frequency of alleles in the gene pool of a population will not change over time, assuming:
1) There is no mutation. 2) There is no genetic drift. 3) There is no out breeding. 4) There is no natural selection. 5) There is no migration. |
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Chapter 5. What are the two equations that can deduced from HH population genetics?
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1) p+q = 1
2) p^2 +2pq+q^2 = 1, where p^2 is the frequency of the dominant homozygous genotype, 2pq is the frequency of the heterozygous genotype, and q^2 is the frequency of the homozygous recessive genotype. |
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Chapter 5. What is the definition of HH equilibrium and how is it reached?
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HH equilibrium describes the phenomenon in which allele frequencies as well as genotype frequencies do not change over time, and this is achieved after one generation after mating two individuals.
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Chapter 5. What is the basis of evolution in terms of the Darwinian perspective?
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A change in the allele frequency.
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Chapter 5. What is one strict requirement o achieve greater fitness for any individual in a population?
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Greater fitness = any means that allows higher chances of an individual passing on his/her genes to the next generation.
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Chapter 5. If a non-heritable trait is introduced into a member of the population (a virus which changes the bone marrow structure of mice that extends their lives, for example), will it result in the extension of life for the whole population? Why or why not?
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No. Natural selection only works on inheritable traits.
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Chapter 5. The gene for cystic fibrosis kills off affected individuals before they reach sexual maturity, but the disease continues to show up in human populations, why?
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Natural selection works on PHENOTYPES not genotypes. Hence, a person can be a heterozygous carrier of the disease and survive, passing it on to his/her offspring who may or may not develop the disease.
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Chapter 5. Can evolution (via natural selection) cause new alleles to appear in a population? How is genetic diversity introduced?
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No.
Genetic diversity is introduced by changing the combination of alleles in a population and also creating new alleles. These are achieved through: 1) Mutations. 2) Crossing over during prophase I. 3) Independent assortment. 4) Segregation. |
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Chapter 5. Can natural selection introduce genetic diversity in a population?
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No, natural selection works with the genetic diversity already present, but cannot create more (only mutations can).
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Chapter 5. If a mutation occurs in the muscle cell of an individual who has many progeny, does this introduce genetic variation in the population?
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No, only changes in germ cell lines can affect the population, not changes in somatic cells.
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Chapter 5. What are the five types of natural selection?
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1) Stabilizing selection-phenotypes at both ends of the bell curve as selected against.
2) Divergent selection-phenotypes at the ends of the bell curve are favored. 3) Directional selection-phenotypes at one end of the curve are selected against and the phenotypes of the rest of the population shifts in the other direction. 4) Kin selection- 5) Artificial selection-humans get to select mates for another population of animals. |
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Chapter 2. What is the equation you use to figure out how many high energy phosphate bonds are used to make a polypeptide chain?
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4n-1, where n is the number of amino acids in the chain.
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Chapter 2. What is a hypotonic solution? A hypotonic solution?
|
A hypertonic solution is a solution which has a higher concentration of solutes than the solution on the other side of the semi-permeable membrane. A hypotonic solution is the opposite.
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Chapter 5. What is the difference between a species and population?
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Members of a species can reproduce sexually, and members of a population do. Also, if two members produce a sterile offspring, then the two individuals are not members of the same species.
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Chapter 5. What is reproductive isolation and what are the two types of reproductive isolation? Give examples of each
|
Reproductive isolation is what keeps members of two species separate by not allowing successful reproduction or reproduction of viable offspring.
Prezygotic reproductive isolation: factors that prevent the hybrid zygote from forming inthe first place. Postzygotic: factors that prevent the development, survival, and reproductive success of the hybrid offspring (e.g., the reproduction of a horse and donkey produces a sterile mule). |
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Chapter 5. What is the difference between cladogenesis and anagenesis?
|
Anagenesis is when one biological species changes so much through time that if it were to travel back in time it wouldn't be able to reproduce with its ancestors.
Cladogenesis refers to the phenomenon when one species diversifies and becomes two or multiple species. |
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Chapter 5. What are two important types of cladogenesis?
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1) Allopatric isolation-cladogenesis initiated by geographic isolation.
2) Sympatric isolation-cladogenesis that arises from the same species in one area (possibly from divergent selection). |
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Chapter 5. Analogous structures arise from convergent or divergent evolution. What about homologous structures? What is parallel evolution?
|
Analogous structures arise from convergent evolution and homologous structures arise from divergent evolution. Parallel evolution arises when two species go through similar evolutionary changes due to similar evolutionary pressures.
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Chapter 5. What was one important component of the modern atmosphere that was missing in the early days of Earth's formation? What was the result?
|
Oxygen gas. As a result, the early atmosphere was a reducing environment and electron donors were prevalent, and organic bonds could form easily without the threat of electron acceptors (O2) from breaking these bonds.
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Chapter 5. Proteins made in the early days without the help of enzymes but with the help of naturally occurring inorganic catalysts are called _____. This type of protein synthesis is called ______ synthesis.
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Proteinoids. Abiotic synthesis.
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Chapter 5. Protobionts are made of what important components? How are they similar and different from cells?
|
Protobionts are made from microspheres (droplets of protonoids), liposomes, and coacervates (complex particles made of peptides, polysaccharides, and nucleic acids capable of catalyzing reactions).
They are similar to cells because their contain a protected environment and perform chemical reactions. They are different mainly because they do not have an organized system of heredity. |
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Chapter 5. What provided the first system of heredity, DNA or RNA?
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RNA.
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Chapter 5. Can RNA polymers spontaneously form in solution?
|
Yes.
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Chapter 3. Is a virus considered a living entity? Do they have any activity outside their hosts? Why?
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No. No. Viruses cannot reproduce on their own, and cannot synthesize biologically important macromolecules.
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Chapter 3. What is the most important characteristic that determines a viruses life cycle?
|
The structure of the virus determines its life cycle.
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Chapter 3. What are the three types of variation seen in viral genomes?
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1) DNA/RNA.
2) Singles tranded or double stranded. 3) Circular or linear genetic material. |
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Chapter 3. Can a virus have both types of nucleic acids at the same time?
|
NO.
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Chapter 3. If a DNA virus has a A:T ratio that is NOT 1:1, then what kind of virus is it?
|
It's a DNA virus with single stranded genetic material.
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Chapter 3. What is one constraint that all viruses face in the spreading of their genetic material?
|
Size. All viruses are very small and the protein coat that packs their genetic material is very rigid.
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Chapter 5. How is it possible for several proteins to be made from one small piece of DNA/RNA?
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Utilize more than one reading frame within the piece of genetic material.
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Chapter 5. Do viruses have the machinery to express their genes that they carry?
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No, they do not have enough space to pack those pieces of machinery. They do not have enough space in their genome to code for those proteins either.
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Chapter 5. What is another name for the protein coat of viruses? What is it made of?
|
Capsid, which provides the external morphology that is used to classify viruses. It's made up of a repeating sequences of protein structures, which can either be helical (rod shaped) or polyhedral (multiple sided geometric figures) or both.
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Chapter 5. Why would viruses infecting plants and some bacteria need to inject their genetic material while others do not?
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Plants and some bacteria have a cell wall that needs to be punctured. Animal cells, on the other hand, do not have a cell wall and the viruses can be endocytosed entirely.
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Chapter 3. What's the difference between naked and envelope viruses?
|
Naked viruses have no outer envelope (outer covering that derives from the plasma membrane of their host).
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Chapter 3. Can a virus infect just about any cell it wants?
|
No. Viral infection is highly specific, and this specificity of hosts is determined by the surface of the virus (regardless of whether the virus is naked or not).
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Chapter 3. If a antibodies for the capsid of a virus are ineffective, what might it suggest about the viruses outer surface?
|
It suggests that the virus is enveloped.
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Chapter 3. What are the two first crucial steps in a viral infection that must occur before the lytic or lysogenic life cycles can begin?
|
1) Attachment of the virus to its host.
2) injection of viral genetic material. |
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Chapter 3. In the lytic cycle of viruses (in particular, T4 phages), one of the first enzymes made is called ____, and what is its purpose? What is the definition of an "early" gene with respect to the lytic cycle?
|
Hydrolase, and its purpose it to degrade the entire host genome, giving an abundance of new dNTPs with which the virus can use to reproduce its own genome.
An "early" gene includes all the genes that are immediately expressed after infection and all the enzymes that are necessary for this expression. |
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Chapter 5. What is one late gene that is expressed in the lytic cycle of viruses?
|
The gene of lysozyme is a late gene in the lytic life cycle. This gene produces an enzyme that is needed to break down the host's cell way in order for the viruses inside the host to exit. One the cell wall is broken down, the intense osmotic pressure causes the host cell to burst, releasing the viral particles.
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Chapter 3. Bacteria cultures in S-labeled cysteine and labeled phosphates are infected with T4 phage. When these phages are used to infect non-radiolabeled bacterial cultures, what isotopes will be found on the inside and outside the newly infected bacteria?
|
The radiolabeled cysteine will be found on the exterior of the bacteria and the radiolabeled phosphates will incorporate into the host genome (phosphates in the DNA) and be found on the inside.
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Chapter 3. A phage with an important capsid gene deleted infects the same as a normal virus with the normal copy of the gene. At the time of host cell lysis, all the released cells can infect new hosts, but the viruses that are released from this new host cannot infect any more hosts. Why?
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The virus with the mutated capsid gene will be able to infect its host with the normal virus since both phages will have the correct capsid. Some of the viruses that come out of this host will be normal (arising from the normal virus) and some will have the capsid from the normal virus but the defective genome. However, all of the released viruses will be able to infect new hosts due to the capsid made from the normal virus, but the virus released with normal capsid with defective capsid gene cannot produce viruses that can infect new hosts.
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Chapter 3. What is different about the lysogenic and lytic life cycles of viruses? What are the advantages of the lysogenic life cycle? What is one consequence? What is this phenomenon called transduction that occurs in viral infections?
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Lysogenic life cycle requires that the virus stays dormant for a while before multiplying in the host and destroying the host cell through the lytic life cycle.
This usually occurs when the viral particle is able to incorporate its genome into the hosts genome. The pros is that each time the host reproduces, the viral genome is reproduced with it, and hence can form twice the amount of virus each time the host divides compared to without the lysogenic life cycle. The consequence is that each time the viral genome activates and starts to reproduce itself, it excises itself from the host genome along with parts of the host's DNA, hence when the newly made viral particles infects another host and stays in the lysogenic life cycle, the virus will integrate the stolen DNA from the last host along with its own genome into the new hosts genome, and this may encode genes for a new trait, which the new host may not have the genes for, this is called transduction. |
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Chapter 3. After a transduction occurs ina viral infection of a bacterial cell, why does the newly integrates "stolen" bacterial gene express itself in the new host, and not repressed along with the integrates viral genes in the lysogenic life cycle?
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Only viral genes are repressed in the lysogenic life cycle because the specific DNA sequences which binds to the repressor protein (promoter region) is only present in the viral genes, not in the bacterial genes.
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Chapter 3. Viruses that infect animals all have hosts with receptors that recognize these viruses and results in the viruses endocytosis into the host. Do these receptors on the host exist solely for the purpose of the virus? What are they used for?
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No, these receptors serve other functions that are important for the functioning of the cell.
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Chapter 3. Why would the mutation of our cell's receptors aimed at providing resistance against microorganisms not be common?
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1) These receptors are often important for normal physiological functioning, which the body/cell cannot compromise.
2) Viruses can usually mutate just as fast to accommodate the changes in their hosts receptors. |
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Chapter 3. The productive cycle is similar to the ____ cycle but with one difference. This cycle is seen only in animal/plant viruses? Why?
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Productive cycle. It is similar to the lytic cycle in that the virus reproduces its genome and essential components within the host but does not lyse the host cell. This is possible only in animal celle because the viral particles can simply exit the host via budding, which coats the virus with the host's plasma membrane, completing its structure. Budding does not lyse the cell as the plasma membrane can reseal after the event has occurred.
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Chapter 3. Retroviruses are RNA (+) or RNA (-) viruses that require what enzyme to successfully reproduce in host? Do they undergo the lysogenic life cycle?
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RNA (+). Reverse transcriptase. Yes.
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Chapter 3. Why do retroviruses only need to encode the gene for reverse transcriptase, and not have it in its capsid, theoretically?
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Theoretically, a retrovirus does not need to have reverse transcriptase, and only needs to encode it because once the virus gets into the host cell, it can rely on the hosts translational machinery to help make the protein.
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Chapter 3. What do double stranded DNA viruses have to encode? Why?
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Double stranded DNA viruses must encode the gene for enzymes that are essential for nucleic acid biosynthesis and DNA replication, so the virus does not have to wait for the host to reproduce to reproduce itself.
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Chapter 3. Why don't RNA viruses have to carry genes that encode for enzymes essential for nuclei acid biosynthesis and RNA replication?
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Because transcription is ALWAYS going on in host cells, so the NTPs (NOT dNTPs) are always present.
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Chapter 3. What is one main constraint that gives rise to the small size of RNA viruses genomes?
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The error rate of RNA polymerization (there is no proofreading activity in RNA polymerase).
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Chapter 3. RNA (+) viruses must always encode the gene for what protein?
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RNA dependent RNA polymerase, because this is what allows the replication of the viral genome, as the host never makes RNA from RNA.
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Chapter 3. What is needed for the successful reproduction of the RNA (+) viruses genome via RNA dependent RNA polymerase?
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A complementary strand (AKA the (-) RNA strans), which the RNA dependent RNA polymerase makes, is what allows the production of the (+) RNA.
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Chapter 3. What is the main difference between (+) RNA viruses and (-) RNA viruses?
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The (+) RNA virus will only need to encode for the RNA dependent RNA pol, but the (-) RNA virus must encode the enzyme as well as have it within the virus, as the virus contains only the complementary strand to the genetic material that encodes viral proteins. (-) RNA viruses contain the template for the mRNA necessary for the virus's survival.
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Chapter 3. How do (-) RNA viruses produce RNA in transcription and replication? Do they use the hosts machinery?
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(-) RNA viruses produce RNA in transcription using the RNA dependent RNA pol. The same enzyme is used to replicate its genome, except now the (+) RNA is used as the template for the production of the (-) RNA.
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Chapter 3. For viruses that need to penetrate their genetic material into their host, where do they get the energy to do this?
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These viruses can store ATP acquired from their previous host in their capsids, which are then used for the power penetration when needed.
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Chapter 3. Why does the release of bacterial/plant viruses from their hosts cause cell lysis and the release animal viruses don't?
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Release of plant/bacterial viruses from their hosts results in cell lysis because the cell wall, which protect the host cells from overwhelming osmotic pressure, is destroyed, thus causing osmosis and cell lysis.
Animal cells, on the other hand, do not have a cell wall and do not need one for protection. |
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Chapter 3. What are three possible shapes of bacteria?
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-Three possible shapes of bacterial cells are: rod shaped, round, and spiral shaped.
-Names are cocci, bacilli, and spirilla, in the same order given above. |
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Chapter 3. What is the difference between gram positive and gram negative bacteria?
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Gram negative bacteria stain weakly with Gram staining and have a thinner layer of peptidoglycan in their cell walls but have an additional outer later of lipopolysaccharide in the outer layer. The space between this outer layer and the cell wall (called the periplasmic space) in Gram negative bacteria are sometime the enzymes needed to degrade antibiotics.
Gram positive bacteria have a thicker layer of peotidoglycan compared to Gram negative bacteria, and are most susceptible to antobiotics. |
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Chapter 3. What does the capsule do for any bacteria (2 things)?
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The capsule allows the bacteria to stick to different surfaces in its environment better and evade the immune system.
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Chapter 3. What is the sole means of locomotion for bacteria?
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Flagella.
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Chapter 3. What do the words monotrichous, amphitrichous, and perithricous indicate for any bacterial cell?
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The number of flagella.
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Chapter 3. Are the structure of the prokaryotic and eukaryotic flagella identical?
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No. The eukaryotic flagella contains the 9+2 microtubule structure, and the prokaryotic flagella doesn't.
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Chapter 3.The motile bacterial cell have ____ that bind to attractants or repellents in a type of movement called _______. The movement is guided by the absolute level of the chemoattractant/chemorepellent or the change in concentration over time of the two chemicals?
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Chemo-receptors.
Chemotaxis. Change in concentration of the chemoattractant/chemorepellent. |
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Chapter 3. What is the pili used for in bacteria?
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The pili is important for the bacteria to attach to their target surfaces. It does play a role in infection.
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Chapter 3. What are the three temperature classes used to classify bacteria?
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1) Mesophiles
2) Psychriphiles. 3) Thermophiles. |
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Chapter 3. What are the four "trophs" used to classify bacteria based on nutrition?
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1) Chemoautptrophs-Build organic molecules from CO2, using the energy from oxidizing inorganic compounds like H2S.
2) Chemohereotrophs-Need organic compounds made by other organisms for energy. 3) Photoautotrophs-use CO2 as sole carbon source and uses the sun as an energy source. 4) Photoheterotrophs-get energy from sun but require organic molecules from other organisms as carbon source. |
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Chapter 3. What is an auxotroph?
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An auxotroph is a bacteria that cannot survive on a minimal medium (which is plated with only glucose) and needs an additional compound to be plated before it can survive. This trait usually results from a mutation for a critical enzyme in the metabolic/biochemical pathway.
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Chapter 3. What are bacteria that needs oxygen to survive called? What about those that don't need oxygen?
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Bacteria that need oxygen to survive are called obligate aerobes and those that don't need oxygen are called anaerobes.
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Chapter 3. What are the three classes of anaerobic bacteria?
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1) Facultative anaerobes-can use oxygen when it's around but don't need it.
2) Obligate anaerobes-bacteria that are poisoned by oxygen (by the inability to eliminate free radicals that result from the presence of oxygen). 3) Tolerant anaerobes-can grow in the presence or absence of oxygen but can't use it in its metabolism. |
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Chapter 3. Is it possible for bacteria to have respiration without the presence of oxygen?
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Yes. Instead of using oxygen as the final electron acceptor, many bacteria use other compounds to play the same role. This ultimately allows the same oxidative phosphorylation and electron transport seen in aerobic respiration.
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Chapter 3. How is asexual reproduction in bacteria different from asexual reproduction in eukaryotes? How do bacteria exchange genetic information?
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Asexual reproduction in eukaryotes occurs through mitosis, which does not occur in prokaryotes.
Conjugation. |
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Chapter 3. What are the four phases seen in bacterial life cycles?
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1) Lag phase-even when conditions are ideal, bacteria need time for all the biosynthesis of important compounds to be occur. This takes time and is called the lag phase.
2) Expoential phase-exponential growth of the bacterial population. 3) Stationary phase-carrying capacity is reached. 4) Cell death phase-cell death may result due to the fact that there may not be enough nutrients in the medium to support all the bacterial cells. |
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Chapter 3. What is the crucial component of a bacterial endospore that provides it protection through the bad times? How many endospores can one bacterium make? Are endospores a means for bacteria to reproduce?
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Peptidoglycan.
One bacterium can only make one endospore, which is why endospores are not a means for reproduction or an expansion of a population. |
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Chapter 3. What are the three ways that bacteria can increase genetic diversity? Do any of these confer reproduction?
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1) Transduction-exchange of genetic material between bacteria via lysogenic phages.
2) Transformation-bacteria internalize externally added DNA. 3) Conjugation-exchange of genetic information between two bacteria. No. |
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Chapter 3. What determines whether a bacteria is male or female? What is the F factor and what genes does it encode?
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The presence of the F facto designates a bacterium as male.
The F factor is an extrachromosomal element (single circular piece of DNA) that encodes the genes conjugation as well as those which may confer an advantage for survival. |
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Chapter 3. How does conjugation in bacteria work?
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One a F+ bacterium has found a F-bacterium, a conjugation bridge forms and the F factor replicates in the F+ bacterium. Afterwards, the replicated F factor travels through the bridge to the F- individual and turns it from female to male.
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Chapter 3. What is the difference between conjugation between F+ and F- bacterium when the F+ bacterium is a HFR vs when the F+ bacterium is not an HFR? How does a HFR form?
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In HFR, the F factor is integrated into the normal genome. Thus, during replication, which occurs before conjugation, some of the normal bacterial genome may get replicated as well and thus would travel to the F- individual after conjugation. Thus does not occur in non HFR F+ bacterium.
An HFR forms as a result of recombination of the F factor and the normal bacterial genome. |
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Chapter 3. How can recombination occur in bacteria (which only carry one copy of any gene)?
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When conjugation occurs between a F+ HFR and F- bacterium, there may be several genes from the genome of the F+ bacterium that are transferred with conjugation to the F- bacterium. This gives room for recombination.
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Chapter 3.How can scientists map the genes on a bacterial chromosome, knowing that bacteria are haploid?
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Scientists would carry out conjugation experiments with HFRs and allow different times for conjugations in each trial, which allows different amount of genes to be transferred from the HFR to the F- (these genes transfer in the order that they are placed in the chromosome). So seeing the order of recombination in the genes gives the relative positions of these genes on the chromosome.The first gene that shows recombination is the gene at the very top and the last gene to show recombination is the gene at the very bottom of the chromosome.
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Chapter 3. Most fungi are uni/multi-cellular, motile/non motile organisms, with the exception of what organism?
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Fungi are mostly multicellular, non motile organisms with the exception of yeast, which is unicellular.
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Chapter 3. Fungi have a substance with which it uses to protect itself (bugs with exoskeletons have this material too) called _______. Fungi are what kind of "trophs"? Are they obligate aerobes?
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Chitin. Fungi are chemoheterotrophs. Most fungi are strict aerobes but some can be facultative anaerobes.
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Chapter 3. What kind of organism is lichen?
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Lichen consists of two organisms, namely a fungus ad algae living together in a symbiotic relationship.
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Chapter 3. Digestion of food for fungi occurs inside or outside the cell? Can yeast use CO2 as a carbon source?
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Diesgtion occurs outside the cell for fungi.
No, fungi are chemoheterotrophs, so they cannot utilize CO2 as a carbon source but must rely on organic compounds from other organisms. |
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Chapter 3. What is the main difference between fungal spores and bacterial endospores?
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Bacterial endospores are not made for reproductive purposes, while fungal spores are.
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Chapter 5. The most fundamental level of structure after the cell for fungi is called the ____. What are the two types called? What is the particular type of this structure that is used for digestion called? A large meshwork of hyphae is called?
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Hypha.
Septate hyphae (cells joined end to end in a long tube but cytoplasmic contents cannot mix) and aseptate hyphae (consists of cells joined together in a long tube in which the cytoplasmic contents can mix). Haustoria. Mycelium. |
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Chapter 3. What are the three sources of food for fungi?
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Fungi are either saprophytes (feed off dead organisms), parasites (feed off of living organisms), or mutualists (live in a symbiotic relationship in which both organisms involved benefit).
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Chapter 3. What are three methods of sexual reproduction in fungi?
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1) Fragmentation-one mycelium breaks into smaller pieces, each of which develops into a separate mycelium.
2) Spore production-spores formed via mitosis are dispersed throughout the environment. Under favorable conditions, the spores germinate into new hypha. 3) Budding-a new hyphae grows out from an existing one. |
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Chapter 3. How does sexual reproduction in fungi work? What specific parts of the fungi are responsible for sexual reproduction?
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Two adult haploid cells meet to form a diploid zygote. This zygote then immediately undergoes meosis to form haploid cells that will form the cells of the new adult fungi. Fusion two gametes produces a dikaryon first (a cell with two nuclei), before the two nuclei fuse and forms one cell.
Gametangia are responsible for producing gametes, a site of fusion for other gametes, or can fuse with other gametangia from the other fungi of the same species. |
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Chapter 3. Can viruses have genomes with introns? What about bacteria?
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Yes, no.
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Chapter 3. Of the three microorganisms: bacteria, virus, and fungi, which one has a DNA dependent DNA polymerase?
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All three.
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Chapter 5. In genetic linkage, there are two ways that two genes can be linked in any heterozygote. How do you determine which?
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Look at the genotype of the parents and see what kind of gametes they can make.
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Chapter 5. How do you decide what a recombinant offspring is in the crossing of genes showing linkage?
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Look at the possible gametes from each parent to figure out the possible genotypes of the offspring. Any genotype in the offspring that doesn't fit these possible genotypes are considered recombinant individuals.
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Chapter 5. In any punett square, if half of the squares don't pertain to the probability that an event will occur, will you consider those two squares as two possible outcomes (the denominator) in the calculation of the probability that en event will occur? Give an example.
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No. For example. if a disease can only occur in boys, you only want to account for the boys (2 squares in the punnet square, rather than all four) and see the chances WITHIN those two squares that en event (a disease) will occur.
Also, you must also multiple the entire probability by the probability that the child turns out to be the sex that gets the disease. YOU MUST NEVER FORGET THIS. |
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Chapter 6. What is the difference between a nerve and neuron?
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A neuron is a single cell and a nerve is a bundle of many axons from different neurons.
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Chapter 6. What is the difference between a nerve and neuron?
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A neuron is a single cell and a nerve is a bundle of many axons from different neurons.
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Chapter 6. The resting membrane potential is _____mV. What two important membrane proteins are important in establishing and maintaining this potential?
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-70 mV = resting membrane potential with interior of cell more negative than exterior.
1) Na+/K+ pumps. 2) K+ leak channels. |
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Chapter 6. The membrane is considered to be polarized when the sodium and potassium ion concentrations are maintained. What would happen is sodium was allowed to freely diffuse down its concentration gradient or if K+ leak channels were dysfunctional?
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The cell would become depolarized and the interior of the cell would become less negative relative to the exterior.
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Chapter 6. Can it be said that an action potential is an electrical impulse?
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No. An action potential involves the movement of ions in and out of neurons, so an AP is an electrochemical impulse.
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Chapter 6. In an action potential, ,each section of a neuron's axon is sequentially depolarized before voltage gated sodium channels open. Does the magnitude of this depolarization of each section of the axon change down the stretch of the axon in an action potential?
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No.
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Chapter 6. The resting membrane potential is _____mV. What two important membrane proteins are important in establishing and maintaining this potential?
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-70 mV = resting membrane potential with interior of cell more negative than exterior.
1) Na+/K+ pumps. 2) K+ leak channels. |
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Chapter 6. The membrane is considered to be polarized when the sodium and potassium ion concentrations are maintained. What would happen is sodium was allowed to freely diffuse down its concentration gradient or if K+ leak channels were dysfunctional?
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The cell would become depolarized and the interior of the cell would become less negative relative to the exterior.
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Chapter 6. Can it be said that an action potential is an electrical impulse?
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No. An action potential involves the movement of ions in and out of neurons, so an AP is an electrochemical impulse.
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Chapter 6. In an action potential, ,each section of a neuron's axon is sequentially depolarized before voltage gated sodium channels open. Does the magnitude of this depolarization of each section of the axon change down the stretch of the axon in an action potential?
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No.
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Chapter 6. What is salutatory conduction in neurons?
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When an action potential "skips" from one Rode of Ranvier to another between Schwann cells.
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Chapter 6.What are three components needed for a neuron to repolarize after depolarization in an action potential?
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1) The immediate shutting off of voltage gated sodium channels, which stay inactivated until the membrane potential returns near the resting potential again.
2) The opening of the voltage gated potassium channels (open slower than sodium channels in response to voltage change, and stay open longer) allow intracellular potassium to escape to the outside, lowering membrane potential to a point a but lower than the actual resting potential. 3) After the voltage gated potassium channels close (after refractory period), Na+/K+ ATPase pumps and K+ leak channels are used to re-establish the correct membrane resting potential. |
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Chapter 6. What is the equilibrium potential and why is it different for each ion, even when they have the same charge?
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The equilibrium potential is describes the potential at which no passive movement of ions across a permeable membrane occurs.
Different ions have different equilibrium potentials because both change and chemical gradients must be taken into account. For example, there is more sodium outside the cell than inside so sodium wants to diffuse into the cell but when the interior of the cell becomes too positive the Na+ is repelled. The electrical repulsion versus the diffusion down the chemical gradient balances out at about +50 mV. The equilibrium potential for potassium is different, despite its identical charge compared to sodium, because of the reversal of its chemical gradients in the interior and exterior of the cell compared to sodium. |
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Chapter 6. The resting potential reflects the equilibrium potential for sodium or potassium? How do we know that there are sodium leak channels just by looking at the cell resting membrane potential?
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Both.
The resting potential is closer to the equilibrium potential of potassium because there are a lot more leak channels for potassium ions than than those for sodium ions. If there were no sodium leak channels, then the cell resting potential would be identical to the potassium equilibrium potential, which is about -90 mV. The reason that the resting potential is slightly more positive is because there are sodium leak channels that allow sodium to come into the cell. However, there are less Na leak channels compared to K leak channels because the resting potential is closer to the equilibrium potential of sodium. |
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Chapter 6. What are the two phases of the refractory period and what factors are responsible for them?
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1) Absolute refractory period-a neuron will not fire another action potential no matter how depolarized it is. During this time, the voltage gated sodium channels are inactivated (NOT CLOSED) and will not be opened again until the cell has returned to resting potential and the channels have returned to their closed state.
2) Relative refractory period-an action potential can be fired is the neuron is depolarized beyond threshold.However, a greater depolarization is required since the cell is hyperpolarized due to having the voltage gated potassium channels still being open. |
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Chapter 6. What are the two types of synapses involve d in synaptic transmission?
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1) Electrical synapses-the cytoplasms of two cells are joined and the action potential of one cell can transmit directly to the other cell.
2) Chemical synapses-electrical impulses in an action potential are converted to a chemical signal at the ends of axons of neurons in an AP. |
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Chapter 6. Explain the steps of the spreading of an action potential via a chemical synapse.
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1) An action potential reaches the end of an axon.
2) and 3) Depolarization of the presynaptic membrane causes the opening of the voltage gated calcium channels, and calcium is influxed into the cell, which causes the release of neurotransmitter molecules stored in secretory vesicles. 4) and 5) Neurotransmitters diffuse across the synaptic cleft and bind to the ligand gated ion channels in the post synaptic membrane. 6) The opening of the ion channels in the postsynaptic membrane causes the postsynaptic cell to depolarize and can fire an action potential depending on whether the threshold voltage is reached or not. 7) Neurotransmitters left in the synaptic cleft is degraded and and/or removed to remove the signal. |
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Chapter 6. Do neurotransmitters have stimulatory effects on the postsynaptic cell?
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No. They can be excitatory (depolarize postsynaptic cell) or inhibitory (hyperpolarize postsynaptic cell), or both (depending on what the receptors do on the post synaptic cell). These receptors can do opposite things in different cells but the identity of the receptor cannot change for each neurotransmitter.
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Chapter 6. How many different neurotransmitters can one presynaptic neuron secrete?
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Each presynaptic neuron can secrete only one neurptransmitter. Each post synaptic neuron can have receptors for many different neurotransmitters.
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Chapter 6. How can a pre-synaptic cell increase the size of the signal it sends.
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Increase the frequency with which the signal (action potentials) is sent.
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Chapter 6. The process of sensing and responding to stimuli is controlled by the CNS or PNS? What are the two types of effectors?
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PNS. Muscle and glands.
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Chapter 6. Do both the autonomic and somatic nervous systems have effectors and sensors? The efferent portion of the autonomic nervous system is split into two portions, what are they?
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Yes. The efferent portion of the autonomic nervous system is split into the parasympathetic and sympathetic nervous systems.
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Chapter 6. What is the peripheral nervous system split into?
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1) Somatic nervous system.
2) autonomic nervous system. |
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Chapter 6. What does the peripheral nervous system split up into? What does this subsequent category split up into?
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1) Somatic and autonomic.
2) Parasympathetic and sympathetic. |
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Chapter 6. What structure does the central nervous system consist of? What fluid circulates these three structures?
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1) Forebrain.
2) Midbrain. 3) Hindbrain. 4) Spinal cord. CSF. |
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Chapter 6. Which central nervous system is mainly responsible for reflexes?
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Spinal cord.
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Chapter 6. What are the two types of summation that determines whether a post synaptic neuron will fire or not?
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1) Temporal.
2) Spatial. |
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Chapter 6. What structures does the hind brain include?
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1) Medulla.
2) Cerebellum. 3) Pons. |
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Chapter 6. Which part of the brain is PARTICULARLY responsible for overall balance of the body and anti-gravity posture? What does the cerebellum do?
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Pons. The cerebellum is an integrating center where all the complex signals of movement (from other parts of the nervous system) are coordinated.
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Chapter 6. Which two parts of the brain (hind, mid, or fore brain) receive information from the vestibular apparatus in the inner ear?
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The pons and the cerebellum. The hindbrain.
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Chapter 6. What constitutes the brain stem?
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The midbrain, the medulla, and pons.
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Chapter 6. What is the mid-brain responsible for? What is the unit of the brain that is largely responsible for arousal (wakefulness)?
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The mid-brain is the relay for visual and auditory information and contains must of the RAS, which is largely responsible for wakefulness.
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Chapter 6. The diencaphalon is part of which part of the brain? What is the other part of this part of the brain? What are its constituents?
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The diencephalon. The forebrain. The telencephalon. The diencephalon is made of the thalamus and hypothalamus. The thalamus is largely responsible for somatic sensation. The hypothalamus is responsible for controlling homeotic functions, such as temperature regulation. It is also involved in primitive emotions such as rage, sexual dive, and hunger.
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Chapter 6. What are the constituents of the telencephalon?
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The telencephalon is made of the cerebral hemispheres plus the basal nuclei (regulating body movements) and the limbic system (emotions).
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Chapter 6. What does each hemisphere of the brain consist of? What is the grey matter made out of?
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Each hemisphere of the cerebrum consists of the cerebral cortex as well as the white mater connecting the cortex to the diencephalon. The grey matter sits on the outer layer of the cerebral hemisphere and the contains billions of neuron cell bodies.
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Chapter 6. What four pairs of lobes is the cerebral cortex divided into? What do each of these lobes do?
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1) Frontal lobe-responsible for initiating all movements and complex reasoning skills.
2) Parietal lobes-general sensation and taste. 3) Temporal lobe-responsible for auditory and olfactory sensation and involved in short term memory. 4) Occipital lobe-processes visual information. |
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Chapter 6. Generally, a larger area of the cortex is devoted to controlling body part that require ______.
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More motor control or more sensation.
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Chapter 6. All neurons entering and exiting the CNS are carried by 12 pairs of nerves called _____, and 31 pairs of ____.
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Cranial nerves. Spinal nerves.
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Chapter 6. The cranial nerves convey ____ and _____ to and from the _____. What about the spinal nerves?
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The cranial nerves convey sensory and motor sensation to and from the brain stem. The spinal nerves convey sensory and motor sensation to and from the spinal cord.
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Chapter 6. The vagus nerve is one of the ______ nerves. It controls the _____, and how does it do so?
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The vagus nerve is one of the 12 cranial nerves. It controls the heart and several visceral organs. It functions to decrease heart rate and speed up GI activity. It is part of the parasympathetic autonomic nervous system.
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Chapter 6. ALL somatic motor neurons innervate the ______, use ____ as their neurotransmitter, and have their cell bodies in the ______.
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All somatic motor neurons innervate the muscle, use ach as their main neurotransmitter, and have their cell bodies in the brain stem or ventral portions of the spinal cord.
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Chapter 6. ALL somatic neurons that bunch up in ____ (where?) in a structure called the ______.
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Cell bodies of the somatic neuron bunch up in ventral portion of the spinal cord or the brain stem in a structure called the dorsal root ganglion.
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Chapter 6. There is a pair of ______ ganglia for every vertebrate in the spinal column. This structure are protected within the _______ but are outside of the ______, and thus it is outside or inside the CNS?
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Dorsal root ganglia. Vertebral column. Meninges (protective sheath of the brain and cord). Thus, the dorsal root ganglia are outside the CNS.
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Chapter 6. In all somatic sensory neurons, the first synapse is always with the PNS or CNS?
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CNS. The axon can synapse either with the spinal cord or directly with the brain.
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Chapter 6. In the PNS, the efferents of both the parasympathetic and sympathetic systems consists of ______ and ________ neurons. Where does each type of neuron have its cell body and axons? What does each synapse with?
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Post ganglionic and pre ganglionic neurons.
The pre-ganglionic neurons have their cell bodies in the brain stem and spinal cord and sends its axons to a autonomic ganglion, which synapses with a post ganglionic ganglion. The post ganglionic neurons synapses with an effector (smoother muscle or gland). |
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Chapter 6. All autonomic pre-ganglionic neurons use what as their neurotransmitter? What about autonomic post ganglionic neurons?
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All autonomic pre and post ganglionic neurons release ACh as their neurotransmitter.
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Chapter 6. What transmitter is release by sympathetic post ganglionic neuron?
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Nor epinephrine.
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Chapter 6. All sympathetic preganglionic efferent neurons have cell bodies in what region of the nervous system? What about parasympathetic preganglionic neurons?
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All sympathetic pre ganglionic neurons have cell bodies in the lumbar (lower back) and thoracic (chest) regions of the spinal cord. All parasympathetic preganglionic neurons have cell bodies in the brainstem or in the lower portions of the spinal cord.
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Chapter 6. ALL autonomic efferent neurons have sensory neurons are similar to _______ afferent neurons with an exception of ________.
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Somatic afferent neurons, with the exception that they synapse with the PNS, not CNS.
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Chapter 6. The post-ganaglionic axons of the sympathetic nervous system is short or long. What about the for the parasympathetic nervous system? What about the pre-ganglionic axons for the parasympathetic and sympathetic nervous system?
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The pre-ganglionic nervous system axons are long for the parasympathetic nervous system and short for sympathetic nervous system. It is the opposite for the post ganglionic axons.
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Chapter 6. In general, the ganglia for the sympathetic nervous system are close or far to the target and close or far from the spinal cord? What about for the ganglia for the parasympathetic nervous system?
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For the sympathetic nervous system, the ganglia are close to the cord and far from the target. For the parasympathetic nervous system, the ganglia are far from the cord and close to the target.
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Chapter 6. What are the two portions of the adrenal gland?
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The adrenal gland has a inner portion is called the medulla and secretes the hormone associated with the sympathetic nervous system called andrenaline (epineprhine), which is similar to norepinephrine but different in that it is not a NS.
The cortex, which is the outer portion of the adrenal gland, secrets glucocorticoids and mineralcorticoids. |
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Chapter 6. What does epineprhine do to the body? Does it elicit a response fast or slow. How long does the response last?
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Elicits the fight or flight response, and stimulates the heart. It elicits a response fast and the response is short lived.
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Chapter 6. Sensory neurons that respond to internal stimuli are called _______, what about sensory neurons that respond to external stimuli?
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Sensory neurons that respond to internal stimuli are called interoceptors and those that respond to external stimuli are called exteroceptors.
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Chapter 6. What are the five types of sensory receptors?
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1) Nocireceptors-senses pain.
2) Chemoreceptors-senses the presence of certain chemicals. 3) Mechanoreceptors-responds to mechanical disturbances. 4) Electromagnetic receptors-responds to EM waves. 5) Thermoreceptors-responds to changes in temperature. |
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Chapter 6. What is the only type of receptor in the nervous system that can adapt to stimuli?
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Sensory.
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Chapter 6. Two of the five possible sensory receptors are innervated by both the somatic and autonomic nervous systems, what are they?
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1) Nocireceptors.
2) Thermorecetors. |
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Chapter 6. What are proprioceptors? Do they belong in the somatic or autonomic nervous system? What is an example? What part of the brain responds to signals from proprioceptors?
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Proprioceptors are a broad class of sensory receptors that sense the awareness of the self (e.g., awareness of body part position). An example are the muscle fibers. Somatic. The cerebellum.
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Chapter 6. After sensory receptors adapt to a certain stimuli, the only way that can fire send signals again is when _____. What are the only sensory receptors that DON'T adapt under any circumstances?
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Changing stimuli. Nocireceptors.
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Chapter 6. The taste buds can only distinguish _____ kinds of flavor. Do all taste buds respond equally strongly to all tastes?
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5. No, each taste bud responds most strongly to one kind of taste.
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Chapter 6. Describe the basic structure of a taste bud.
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Taste buds are made of concentric rings of epithelial cells, with taste pores at the center, which contain taste hairs that can detect food chemicals.
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Chapter 6. What are three examples of mechanoreceptors?
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1) Vestibular hair cell.
2) Auditory hair cells. 3) Pacinian corpuscles-pressure sensors located deep in the skin. |
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Chapter 6. Olfactory nerves project directly into what part of the brain.
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The olfactory bulb.
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Chapter 6. The ____ and _____ comprise the outer ear, which is separated from the middle ear by the _______. The middle ear consists of the ______, ______, and ______. The part of the ear that separates the middle ear from the inner ear is called the ______. The inner ear consists of ____, ____, _____, and _____. What three structure in the inner ear are important for the sense of balance?
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Auricle, pinna = outer ear.
Tympanic membrane AKA eardrum. Middle ear = Ossicles, stapes, and incus. Oval window. Cochlea, semicircular canal, utricle, saccule. Semicircular canal, utricle, saccule are structures of the inner ear important for the sense of balance. |
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Chapter 6. The _____ tube is that connects the what with what? and it is important for equalizing pressure on both sides of the eardrum.
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Connects the back of the throat to the middle ear. Eustachian Tubes.
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Chapter 6. Sound is transmitted to the brain as a signal first as sound, then as a ____, and finally as a ____before the signal is relayed to the brain.
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Sound travels first through the air, then as vibrations of the bones of the middle ear, then as liquid vibrations before being transmitted to the brain as an electrical signal.
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Chapter 6. What is the mechanism of hearing after the sounds as traveled through the outer and middle ear? (particularly in the cochlea)
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Once past the stapes of the middle ear, sound travels through the endolymph and the perilymph, which are liquids in the cochlea of the inner ear, which stimulate the hair cells on the basilar membrane of the cochlea. The hair cells have cilia projecting from the apical surface (opposite of the basilar membrane), and thee hairs contact the tectorial membrane. When sounds arrives at the cochlea, the basilar membrane moves, and the hairs are dragged across the tectorial membranes as hey bend, which opens up ion channels in the hair cells and NS release.
The NS will cause afferent bipolar auditory neurons to fire and send a neural signal to the brain. |
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Chapter 6. What does the Organ of Corti consist of?
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1) Techtorial membrane.
2) Basilar membrane. 3) Hair cells. |
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Chapter 6. How is pitch and loudness distinguished by the ear?
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Pitch (frequency) is determined by which areas of the basilar membrane the sound stimulates (high frequency sounds stimulate the hair cells at the base of the cochlea, near the oval window, and low frequency sounds stimulate hair cells at the apex of the cochlear duct)
Loudness is distinguished by the amplitude of the vibration. Larger vibrations cause from frequent action potentials in the auditory neuron. |
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Chapter 6. The semicircular canals contain what structures detect _____________. They are innervated by afferent neurons which send signals to the _______ and ______ of the brain.
What two other parts of the ear are responsible for detecting balance? |
The semicircular canals contain hair cells to detect rotational acceleration of the head.
Pons and cerebellum. Utricle and saccule. They detect static equilibrium and linear acceleration. |
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Chapter 6. Light first enters the eye through the _______, which is continuous at its borders with the white of the eye, which is called the _______. Beneath the white of the eye is the _________, which contains _________ that does what? Beneath this structure is what, which does what?
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Cornea.
Sclera. Chroroid-dark pigmentation, which absorbs the excess light. Retina, which is the surface where the light is focused. |
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Chapter 6. Just inside the cornea is a chamber called the _______ which contains _______. At the back of the anterior chamber is a membrane called the _______, with an opening called the ______.
What muscles innervate the diameter of the pupil? Behind the iris is what structure, with what purpose? What muscles control the curvature of the light that enters this structure? |
Anterior chamber.
Aqueous humor. Iris. Pupil. Muscles in the iris control the diameter of the pupil. Lens. Ciliary muscle. |
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Chapter 6. After traveling through the lens, light travels through the ________, and then finally to the ________, which has EM neurons called ________ and _______ responsible for detecting light. These cells synapse with _______, which in turn synapse with ________, that send signals which part of the brain for analysis?
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Vitreous humor.
Retina, rods and cones. Bipolar cells, ganglion cells. Occipital lobe. |
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Chapter 6. The point where many axons from the ganglion cells converge to form the optic nerve is called the _____.
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Blind spot.
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Chapter 6. What is the macula?
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At the center of the macula is the fovea centralis, which contains only cones and is responsible for extreme visual acuity.
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Chapter 6. What changes are seen in the photo-resceptor neurons as light hits it? What molecule is responsible in particular?
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Rods and cones contain special pigment proteins called retinal, which when unstimulated by light, has one cis double bond among trans double bonds. Upon stimulation, all the double bonds become trans and several other changes occur, culminating a change in the transmembrane potential and the rod/cone ends up releasing neurotransmitters.
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Chapter 6. Night vision is more accommodated by rods or cones? Where are rods more concentrated in the eye? What about cones?
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Night vision is better accommodated by rods which are more concentrated more in the periphery of the retina. Cones require more light and are responsible for color vision and high acuity vision. Cones are more concentrated in the fovea.
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Chapter 6. How many different cones are responsible for color vision? What color does each cone detect? How is it possible that one con can detect a different color from another?
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Three. Blue, green, red. Each cone has a slightly different pigment protein structure such that only a certain wavelength of light can change its conformation and stimulate it.
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Chapter 6. Abnormal vision is caused by ______. What are the three types, how do they arise, and how are they treated?
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Abnormal vision is usually caused by too much or too little curvature of the lens or cornea. Too much curvature causes light to be bent to much and focused in front of the retina. This is near-sightedness, AKA myopia, and is corrected by concave glasses.
The other type of abnormal vision is called hyperopia, AKA far sightedness, and is caused by the focusing of light behind the retina. Hyperopia is corrected by convex lens. The final type of abnormal vision of presbyopia, which is the inability of the eye to focus light, resulting from the weakness/lack of flexibility of the lens, and often occurs with aging. |
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Chapter 6.Hormones are often grouped into two categories, what are they and how do they function differently?
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Hormones are classified as either hydrophobic or hydrophilic hormones. Hydrophilic hormones attach tor receptors on the cell surface and hydrophobic hormones must attached to receptors in the target cell's interior.
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Chapter 6. Peptide hormones are usually hydrophilic or hydrophobic? How do they communicate with the interior of the cell?
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Hydrophilic. They communicate with the interior of the cell via second messengers.
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Chapter 6. What are the two types of peptide hormones? Give an example of each.
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Peptide hormones are either amino acid derivatives or polypeptide hormones.
Epinephrine is an example of an amino acid derivative peptide hormone and insulin is an example of a polypeptide hormone. |
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Chapter 6. Steroid hormones are synthesized from what molecule in the ____ ER (smooth of rough). Can they be dissolved in the plasma. If not, then how do they travel within the bloodstream?
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Cholesterol. Smooth ER. No, they cannot dissolve in the bloodstream, and must stick to certain transport proteins (e.g., albumin) via hydrophobic interactions.
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Chapter 6. How do steroid hormones exert their effect on the cell. Compared to peptide hormones, do steroid hormones take longer or shorter to effect the target cell, what about the duration of the effect?
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Steroid hormones can freely diffuse into the target cell, and bind to a receptor in the cytoplasm. Once bound, the hormone-receptor complex can enter the nucleus and act as a sequence specific regulatory of transcription.
Steroid hormones usually take longer to elicit a response in the target cell and the duration of effect is usually longer as well. |
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Chapter 6. Steroid hormones regulating sexuality, reproduction, and development are secreted by the ____, ____, and ______. What about steroid hormones that control water balance and other processes?
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Steroid hormones that regulate sexuality,reproduction, and development are secreted by the testes, ovaries, and placenta.
Steroid hormones that regulate water balance and other processes are secreted by the adrenal cortex. |
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Chapter 6. Peptide hormones specifically regulated the activity of __________.
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Peptide hormones bind to receptors on the surface of the cell and generally communicate with the cell interior via second messengers. These sigals often serve to modify/regulate specifically cytoplasmic enzyme activity.
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Chapter 6. When are peptide and steroid hormones made and released into the bloodstream?
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Peptide hormones are made and stored in vesicles until needed.
Steroid hormones are made only when needed, and are never stored. They are released immediately. |
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Chapter 6. The hormones that serve as regulators, and regulate the activity of other hormones are called ______>
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Tropic hormones.
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Chapter 6. Most of the feedback loops in the endocrine system are positive or negative?
The hormones that ACTH regulates are all secreted from the ____. Is the amount of ACTH in the bloodstream regulated? |
Negative. Adrenal cortex. Yes, just like hormones that regulate physiological endpoints, tropic hormones are regulated by the concentration of the hormones they regulate in the bloodstream.
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Chapter 6. In the endocrine system, hormones that regulate other tropic hormones are secreted from the _______. What are these hormones called?
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Hypothalamus. These hormones that regulate other tropic hormones are called releasing and inhibiting factors.
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Chapter 6. The hormone secreted by the hypothalamus to regulate ACTH is called _____. Hormones secreted from the hypothalamus controls the anterior or posterior pituitary gland, which controls most of the rest of the endocrine system.
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CRH. Anterior pituitary gland.
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Chapter 6. The hormones secretes by the hypothalamus enters a special part of the bloodstream specifically designed for efficient delivery of these hormones to the pituitary gland called _______.
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Hypothelamic-pituitary portal system.
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Chapter 6. Does the blood leaving one structure that is connected to another via a portal system go to the heart first like the general circulation or does it go straight to the other structure on the other side of the portal system?
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Blood leaving one structure connected by a portal system goes straight to the other end without passing the heart. The two portal systems important for the MCAT are the hypothalamic-pituitary portal system and the hepatic portal system.
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Chapter 6. What is the posterior pituitary gland made up of, what controls it, and what are the hormones secreted by this gland?
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The posterior pituitary gland is made up of axons which descend from the hypothalamus. These axons and their cell bodies are called neuroendocrine cells, which are neurons that secrete hormones into bloodstream.
The two hormones secreted by this gland are ADH, which causes the kidneys to retain water during times of thirst and oxytocin, which causes milk let down for nursing as well as uterine contractions during labor. |
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Chapter 6. What two endocrine hormones have broad effects on energy usage and metabolism?
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Thyroid hormone and cortisol. Thyroid hormone is secreted by the thyroid gland in response to TSH stimulation, which is in turn regulated by the hypothalamus and the central nervous system.
Cortisol is secreted by the adrenal cortex in response to ACTH stimulation. It helps the organism deal with stress, by mobilizing glycogen and fat stores to provide energy during stress, and also increase the consumption of proteins for energy. |
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Chapter 6. Would the inhibition of protein synthesis affect the actions of the thyroid hormone?
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Yes, because the thyroid hormone is a hormone that affects transcription, which needs translation and protein synthesis to function in order to work.
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Chapter 4. When do bacteriophages unpack their genome from their capsid?
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Bacteriphages never "unpack" their genetic material from their capsids. They are requires to inject the genetic material directly into the bacteria. They do not behave the same way as animal viruses.
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Chapter 6. Nerve cells that control thermoregulation are located in which structure of the brain?
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Hypothalamus.
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Chapter 6. Is the contraction of heart muscles controlled by neural stimulation?
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No.
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Chapter 6. Where do all action potentials begin on a neuron, specifically?
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All action potentials begins on the axon hillock, NOT at the dendritic spine where the NS takes its effect.
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Chapter 6. Do all excitatory NS's cause action potentials?
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NO. NS's cause membrane depolarizations but not actions potentials, unless membrane depolarizes beyond threshold value.
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Chapter 6. Which is more important to re-polarizing a neuron that just fired an AP, the closing of Na+ voltage gated channels or the opening of K+ voltage gated channels?
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The closing of Na+ voltage gated channels.
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Chapter 6. What is the Nernst equation one uses to find the trans-membrane potential created a particular ion?
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EMF(i) = 60 mV x log ([i outside]/[i inside])
Always take into account what the initial conditions are (concentration inside is greater or less than the concentration outside) and use that to evaluate whether adding excess amounts of that ion outside or inside the cell would depolarize or hyperpolarize the cell. |
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Chapter 6. Are there any voltage gated sodium channels in parts of the axon that are covered by myelin sheaths?
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No.
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Chapter 6. What two main characteristics of an axon affect how fast an AP can travel?
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1) Axon diameter.
2) Whether the axon is mylinated. |
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Chapter 6. Which has more neurons with mylinated axons, the CNS or PNS?
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CNS.
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Chapter 6. What hormones are released from the hypothalamus (those that affect the anterior pituitary)
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Releasing stimulating factors (peptide hormones).
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Chapter 6. What are the three classes of hormones secreted by the anterior pituitary? What are the hormone's names in each class and what does each hormone do?
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Class I.
1) Prolactin-mammary gland/milk production. 2) Growth hormone-Increases bone and muscle growth and cell turnover rate. Class II. Tropic hormones 1) TSH-increased secretion of thyroid hormone. 2) ACTH-increased growth and secretory activity of the adrenal cortex. III. Gonadotropic hormones 1) LH-ovary/ovulation. Testes, testosterone synthesis. 2) FSH-ovary/follicle development, testes/spermatogenesis. |
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Chapter 6. What are the two hormones secreted by the posterior pituitary gland?
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1) ADH, which is responsible for water retention and works on the kidney.
2) Oxytocin-breast milk letdown, uterus contraction. |
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Chapter 6.What is the main hormone secreted from the thyroid gland called?
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1) Thyroid hormone, or thyroxine, which is necessary for physical and mental development in children and also in adults the elevation of body temperature and metabolic rate.
2) Calcitonin-works on the bone and kidney and works to lower serum concentrations of calcium. |
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Chapter 6. What hormone is secreted from the parathyroid? Where does it act and what does it do?
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The parathyroid hormone is secreted from the parathyroid gland. This hormone works on the bones, kidneys and small intestines and increases serum concentrations of Ca++.
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Chapter 6. What hormone does the thymus secrete and what does it do?
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The thymus secretes thymosin, which is responsible for T cell development in children only.
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Chapter 6. Where is epinephrine secretes? and what does epinephrine do?
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Epinephrine is secreted from the adrenal medulla and is responsible for eliciting the sympathetic stress response. This hormone elicits the fast stress response.
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Chapter 6. What three hormones are secreted from the adrenal cortex and what do each of them do? Where do they act?
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1) Aldosterone-works on the kidney to increase b.p. and also Na+ re-absorption.
2) Glucocorticoids or cortisol-responsible for long term stress response, which includes increased concentrations of blood glucose, increased protein catabolism for tissue repair, decreased inflammation, etc. 3) Sex steroids-not important unless tumor causes over secretion, leading to masculinization or feminization. |
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Chapter 6. What hormone do the alpha cells of the pancreas secrete? What do they do? What about the Beta cells?
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The alpha cells secrete glucagon, which increases the plasma concentration of glucose and decreases glycogen and fat storage. The beta cells secrete insulin, which lowers the plasma concentrations and glucose and increases glycogen synthesis and fat storage.
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Chapter 6. Other tan insulin and glucagon, what other hormone is secreted from the pancreas?
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Somatostatin-which inhibits many digestive processes.
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Chapter 6. What hormone does the heart secrete? Where does it act and what does it do?
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The heart secretes ANF-which acts on the kidneys to increase urination and decrease blood pressure.
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Chapter 6. What hormone does the kidney produce, where does it act, and what does the hormone do?
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The kidneys secrete erythropoietin, which acts on the bone marrow to increase production of red blood cells.
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Chapter 7. What is the difference between anoxia and ischemia?
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Anoxia describes a situation when you have adequate circulation but where is a lack of oxygen. Ischemia is when you have enough oxygen but not adequate blood flow. Ischemias are worse because it causes waste products to pile up and the cells receive inadequate oxygen as well because of the bad blood flow.
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Chapter 7. What are the only two system in which blood travels travels through more than one set of capillaries before returning to the heart?
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Portal systems (the hepatic and hypothalamal-hypophysial portal systems).
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Chapter 7. Will the pituitary be completely dysfunctional if the portal system between the hypothalamus and the pituitary is severed?
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No, but the pituitary gland will not be regulated by the hypothalamus as effectively without the portal system, as the hormones would have to travel from the hypothalamus through the entire body before arriving at the pituitary gland.
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Chapter 7. The right side of the heart is always responsible for pulmonary/systemic circulation?
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Pulmonary circulation.
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Chapter 7. What is the only artery in the body that carries deoxygenated blood?
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The pulmonary artery.
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Chapter 7. Which side of the heart usually receives deoxygenated blood? and how does the blood re-enter the general circulation?
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The right atrium of the heart receives deoxygenated blood from the larger veins (interior or superior vena cava), and this blood is pumped to the right ventricle. From the right ventricle, the blood is pumped into the lungs, and from the lungs to the left atrium and left ventricle. Oxygenated blood returns to the heart via pulmonary veins and is then pumped from the left ventricle to the aorta and finally to the general circulation.
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Chapter 7. Blood in the ______ is the only deoxygenated blood that doesn't enter the heart through the superior or inferior vena cava. Instead, it enters the heart via ______.
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Coronary sinus. Blood in the coronary sinus enters the heart by directly draining into the right atrium.
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Chapter 7. Coronary sinuses are merged structures from the ____.
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Coronary veins.
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Chapter 7. What do valves in the heart serve to do? What are the two types of AV valves in the heart?
|
The valves in the heart serve to prevent backflow.
The AV valves are valves between the ventricles and atria in each side of the heart. |
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Chapter 7. The AV valve between the left atrium and left ventricle is bisucpid or tricuspid? What about the AV valve between the right atrium and right ventricle?
|
The AV valve between the left atrium and left ventricle is the bicuspid valve and the AV valve between the right atrium and right ventricle is the tricuspid valve.
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Chapter 7. What would happen if the AV valve in the left side of the heart failed?
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Blood would be pumped into the aorta and left atrium at the same time.
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Chapter 7. Why is it necessary to have semilunar valves?
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The semilunar valves are between the large arteries and ventricles. These are necessary because when the ventricles relax, it's at a low pressure state and blood can easily flow back into the left atrium without these semilunar valves.
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Chapter 7. What is the main driving force that moves venous blood in veins? What stops it from back flowing?
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Skeletal muscle contraction. Valves.
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Chapter 7. What are the two phases of the heart cycle?
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1) Diastole-ventricles are relaxed and blood is able to flow back from the atria.
2) Systole-ventricles contract and blood is pumped out of the ventricle. |
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Chapter 7. What ultimately causes the AV valves to slam shut and the semilunar valves to fly open? When do the semilunar valves close?
|
The buildup of pressure in the ventricles causes the AV valves to shut and the semilunar valves to open. The semilunar valves close when the pressure in the ventricles begins to decline after allthe blood has rushed out into the aorta.
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Chapter 7. The "lub" in the "lub-dub" in every heartbeat is the sound of _______, what about the "dub?" Is the diastole or systole longer in duration?
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The "lub" is the sound of the closure of the AV valves at the beginning of the systole.
The "dub" is the sound of the semilunar valves closing at the end of the systole. The diastole lasts longer, since it takes up the time between each "lubdub." |
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Chapter 7. How is the heart rate calculated? Do stronger hearts have higher or lower heart rates?
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The heart rate is calculated as the number of "lubdub" cardiac cycles that occur per minute.
Stronger hearts have lower heart rates, since they are able to pump more blood per cardiac cycle compared to weak hearts. |
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Chapter 7. How is the cardiac output, of the blood pump rate calculated?
|
Cardiac output (liters/min) = stroke volume (liters of blood pumped per systole or beat)(heart rate measures in beats per minute)
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Chapter 7. Which has the larger cardiac output? the left or right ventricle?
|
Both ventricles have equal cardiac output, or else blood would back up either in the systemic or pulmonary circulation.
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Chapter 7. What is the Frank Staling mechanism?
|
The Franklin-Stalin mechanism serves to increase cardiac output by increasing venous return, which stretches the cardiac muscles and results in stronger contractions of the heart leading to more blood being pumped from the heart back into the systemic circulation.
Venous return can be achieved via urinating less (increasing total volume of blood) and contraction of large veins (valves in the veins are crucial here). |
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Chapter 7. What are the two ways to increase cardiac output?
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1) Increase heart rate.
2) Frank-Staling mechanism (increase stroke volume). |
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Chapter 7. What is one similarity between cardiac muscle and skeletal muscle?
Are the atria and ventricles in the same syncytia? Are there chemical synapses in the cardiac muscle? |
-Similarity: cardiac muscle and skeletal muscle both have the ability conduct action potentials across plasma membranes.
-Difference: The cardiac muscle are in a functional syncytium, which mean that each cell is locked in a gap junction with the other and the depolarization between each cell can be communicated via this method. No. There are no chemical synapses in cardiac muscle, only electrical ones. |
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Chapter 7. What system must be functional for the action potential to be transmitted from the atrial syncitum to the ventricles?
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The cardiac conduction system.
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Chapter 7. What two types of voltages channels are important in cardiac muscle?
|
1) Na+ voltages gated channels-AKA the fast channels, causes membrane depolarization during an action potential.
2) Ca++ voltage gated "slow" channels-stay open longer and cause the action potential to last longer than a neural action potential. |
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Chapter 7. Transmission of the action potential is delayed as it passes through this structure of the heart.
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The AV node.
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Chapter 7. What is one direct results from the long depolarization of cardiac muscle?
What ultimately causes the contraction of the cardiac muscles? How does the heart maximize the concentration of this substance? |
Contraction of cardiac muscle lasts a longer time with longer times of depolarization, and strengthens the force with which the blood is expelled fro, the heart.
Ca++ is what ultimately causes the heart muscles to contract. Ca++ is maximized when needed through T tubules, on which the action potential travels down and induced extracellular Ca++ to enter the cell as well as triggering the sarcoplasmic reticulum to release intracellular Ca++. |
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Chapter 7. Will the absolute refractory period be longer in cardiac muscle or skeletal muscle?
|
The absolute refractory period is longer in cardiac muscle because membrane depolarizations last much longer in cardiac muscle than skeletal muscle or neurons. Membrane depolarizations are considered part of the absolute refractory period because it prevents the next action potential from starting.
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Chapter 7. Can the heart be stimulated to contract via hormonal or neuronal signals? Can it be affected by them?
|
The heart cannot be stimulated to contract via hormonal and neuronal signals. The rate and strength of contraction, however, can be affected by these factors.
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Chapter 7. What initiates the action potential in the heart that gets its to begin beating? Its action potentials are divided into what phases?
|
The SA node, with its action potentials divided into three phases: phase 0, phase 3, and phase 4.
Other cardiac myocytes have phases 1 and 2, but note the SA node. |
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Chapter 7. What are the four phases of the action potential in the SA node?
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-Phase 0: Voltage gated calcium channels open, giving an influx of Ca++.
Phase 3: Repolarization, manifested by the closure of the Ca++ channels and the opening of the K+ channels, which drives K+ out of cell and drives the membrane potential down towards the negative K+ equilibrium potential. Phase 4: Unstable resting potential or automatic slow depolarization, in which Na+ leak channels slowly depolarize the cell to the the threshold for Ca++ voltage gated channels to open. |
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Chapter 7. In terms of pacemaking activity, what happens when the cells of the SA node become dysfunctional?
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While other parts of the heart can spontaneously depolarize, only the SA node can set the pace of the heartbeat because it has the most Na+ channels, meaning that it will reach threshold before any other parts of the heart that can depolarize spontaneously.
When the SA node fails, these other parts of the heart can take over as the pacemaker, but will pace the heart at a slower rate. |
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Chapter 7. What are the five phases of cardiac myocyte contraction?
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-Phase 0: Fast Na+ channels open and Na+ influx results.
-Phase 1: Na+ channels close and K+ channels open, causing an K+ efflux. -Phase 2: Ca++ channels open and Ca++ influx while K+ efflux as K+ channels are still open. -Phase 3: Ca++ channels close and K+ channels still open, giving more K+ efflux. -Phase 4: K+ channels close. |
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Chapter 7. The action potential in the heart can be transmitted without causing contraction via what? Outline the destinations of this specialized pathway.
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Special conducting pathways. This pathway starts in the SA node and goes to the AV node. From the AV node, the action potential travels to the ventricles via the AV Bundle, which is first divided into the left and right bundle branches and then into the Purkinje Fibers, allowing the impulse to be spread evenly to the bottom of the bottom of the ventricles (which is why contraction of the ventricle starts at the bottom).
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Chapter 7. How does the parasympathetic autonomic nervous system control the contraction of the heart?
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The autonomic nervous system connects with the heart via the vagus nerve (parasympathetic nervous system) which has preganglionic nerves that synapse near the ganglia near the SA node. The post ganglionic nerves innervate the SA node and releases ACh, which binds to receptors on the SA node of the heart and prevent depolarization.
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Chapter 7. How are the contractions of the heart affected by the sympathetic nervous system?
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sympathetic post ganglionic neurons directly innervate the heart by releasing norepinephrine. Also epinephrine is secreted from the adrenal glands which also stimulate heart rate.
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Chapter 7. The heart rate and the _____ are closely regulated. What is one key example of this?
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Blood pressure. One key example are the baroreceptors in the aortic arch, which can detect the blood pressure and send the information up to the CNS, which can adjust the heart contractions by either the parasympathetic or sympathetic route.
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Chapter 7. What is the driving force for blood flow?
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The pressure difference between the arteries and veins. This pressure gradient is dependent only on blood flow (cardiac output) and resistance.
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Chapter 7. What can change pressure as it relates to blood flow? What about resistance?
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Pressure can be varied by increasing the force of rate of cadiocontraction.
Resistance can be determined by the degree of constriction by the arteriolar smooth muscle, AKA precapillary sphincters. If they contract, it becomes harder for the blood to flow from the arterioles to the capillaries, and thus increasing resistance. |
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Chapter 7. Does the sympathetic or parasympathetic nervous system control resistance to blood flow?
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Sympathetic. A basal level of pressure is maintained by the release of norepinephrine by sympathetic post ganglionic innervating the pre-capillary sphincters. Resistance can be increased by secreting more norepinephrine. Also, some pre-capillary sphincters (in the gut) can be preferentially contracted (increase blood pressure) and others preferentially relaxed by this type of control following a fight or flight response by the body.
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Chapter 7. What are physicians really measuring when they take a patient's blood pressure? What are the two numbers that are reported? What do they mean?
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Systemic ARTERIAL pressure. The diastole and systole pressures. The systolic blood pressure is the highest the blood pressure gets in the patients during the time the blood pressure is taken, and occurs just as the ventricles contract. The diastolic bp is the lowest pressure that is measured between heartbeats. REMEMBER THAT THE PRESSURE TAKEN ARE ARTERIAL PRESSURE, THE VENAL PRESSURES ARE USUALLY VERY LOW TO ALMOST ZERO AT THE VENA CAVA.
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Chapter 7. What prevents the diastolic pressure from going down to zero?
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The pressure exerted by the walls of the artery.
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Chapter 7. Does the nervous system determine EVERY facet of blood flow?
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No. Sometimes, tissues in need of blood can requisition it themselves. Typically, this happens, when metabolic wastes build up, and this automatically causes local blood vessels to vasodilate (causing arteriolar smooth muscle), allowing more blood flow to the area. This phenomenon is called local auto-regulation.
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Chapter 7. The composition of blood is split into _____ and _____. What is main buffer in the blood? Most of the blood proteins are made by what organ in the body? The principle metabolic waste product is ____.
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Plasma (liquid portion) and the formed elements (cellular portion). Bicarbonate. Liver. Urea.
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Chapter 7. Albumin is essential for the maintenance of _____. Fibrinogen is essential for ______. These proteins are all proteins of the ______.
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Albumin and Fibrinogen are both blood proteins. Albumin is essential for the maintenance of oncotic pressure, which is the osmotic pressure due only to plasma proteins.
Fibrinogen is essential for blood clotting. |
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Chapter 7. The main carrier of excess nitrogen in the blood is _______, it is also a breakdown product of _____. The other important metabolic waste product in the blood is ______, which is a breakdown product of heme.
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Urea. AAs. Bilirubin.
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Chapter 7. All the formed elements in the blood derive from what part of the body?
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Bone marrow stem cells.
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Chapter 7. What is the difference between serum and plasma?
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Serum is liquid portion that is left over when whole blood is allowed to clot. It contains the plasma and all the dissolved proteins. Plasma contains only the liquid portions of the blood, and no dissolved proteins.
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Chapter 7. What is the difference between a RBC and a typical cell? how does it get ATP? How are aged RBCs eliminated from the body?
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RBCs have no nucleus and organelles. RBCs gets ATP from gycolysis. Aged RBCs are eliminated from the body by phagocytosis in the liver or spleen.
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Chapter 7. After blood is centrifuged, what are the three layers seen?
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1) Plasma-blood proteins, metabolic wastes, glucose, hormones, etc.
2) Leukocytes-WBCs and platelets. 3) Hematocrit-RBCs. |
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Chapter 7. What are the three main classes of leukocytes? What are the kinds of cells that are in each class?
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I. Monocyte:
1) Macrophage-cells that move by ameboid motility and respond by chemotaxis. They destroy foreign particles by phagocytosis . II. Lymphocytes: 1) B cells- 2) T cell- III. Granulocytes: 1) Neutrophils: behave much like macrophages, and are the primary component of pus. 2) Eosinophil-Destroy parasites; allergic reactions. 3) Basophil-store and release histamine; allergic reactions. |
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Chapter 7. What is hemostasis and what are the two types of cells responsible for it?
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Hemostasis is the body's mechanism for stopping bleeding.
1) Platelets-forms a platelet plug at the site of injury to stop bleeding. Platelets have no nuclei like RBCs and derive from the fragemented large bone marrow cells called megakaryocytes. 2) Fibrin-derived from fibrinogen, which is activated to fibrin with thrombin, which depends on vitamin K, calcium, and other accessory proteins to function. Fibrin is a threadlike proteins that forms a mesh around the platelets, holding them together. It forms the scab when it dries. |
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Chapter 7. What are the three factors that stabilize the tense conformation of hemoglobin?
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1) Decreased pH.
2) Increased partial pressure of CO2. 3) Increased temperature. |
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Chapter 7. What are the three ways that carbon dioxiode is transported in the blood?
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1) CO2 can be converted to carbonic acid via the RBC enzyme carbonic anhydrase. Carbonic acid is extremely water soluble and can travel easily in the blood.
2) Some CO2 can be stuck onto RBCs (NOT on O2 binding sites). 3) CO2 is somewhat water soluble by itself. So some CO2 can dissolve in the blood. |
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What's the importance of intercellular clefts? What what substances diffuse out of these clefts? Do CO2 and O2 need to use these clefts?
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Intercellular clefts are spaces between endothelial cells that have space for nutrients, wastes, and leukocytes (WBC, and neutrophils with ameboid motility) to diffuse through.
No, CO2 and O2 can pass through any cell through simple diffusion. |
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Chapter 7. At the beginning of the capillary, the hydrostatic pressure is high or low? and water tends to flow in or or of the capillary? As water leaves the capillary, the plasma protein concentration tends to go _____ and as you reach the end of the capillary, the hydrostatic pressure is high or low? and water flows in or out?
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At the beginning of the capillary, the hydrostatic pressure is high as plasma proteins concentrations are low and water squeezes out into the tissue. As you leave the capillaries the plasma protein concentrations go up and the hydrostatic pressure goes down, leading water to enter the capillary.
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Chapter 7. What are the two factors that often draw water out of the capillaries?
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1) High osmolarity of the tissue.
2) The high hydrostatic pressure creates by the heart. The body deals with this by creating an osmolarity in the blood called oncotic pressure through plasma proteins which are too big to diffuse through the intercellular clefts. This keeps the water in the capillaries. |
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Chapter 7. What is one example where a large net loss of water from capillaries would result?
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Inflammation, where the intercellular clefts are enlarged to allow more diffusion of leukocytes. This also gives enough room for plasma proteins to diffuse out into the tissue and result in the loss of water. The lost proteins are returned to the bloodstream via the lymphatic system.
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Chapter 7. What are the three types of immunity the body has?
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1) Innate-general, non-specific protection against pathogens. This includes physical barriers like the skins or extreme acidity like that of stomach acid. Tears, saliva, macrophages, neutrophils and the complement system are also examples.
2) Humoral-involves B cells and antibodies 3) Cell mediated-involves T cells. |
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Chapter 7. What do antibodies bind to specifically?
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Antigens, which can range from being proteins on the surface on the bacterial cell to viral capsids, toxins in the blood, or small portions of a large protein.
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Chapter 7. The small site on an antigenic protein that antibodies bind to is called the ______.
Often, smaller proteins will not elicit antibody production, but will once bound to a larger antigenic protein. In this case, the larger antigenic protein is called the ______ and the smaller protein is called the _______. What are three ways that the body can dispose of a molecule coated with antibodies? |
Epitope.
Carrier. Hapten. 1) Complement system can induce the puncturing of holes in the cell, causing the cell to lyse. 2) Phagocytosis by macrophages and neutrophils. 3) Inactivation of the antigen (viral particles can no longer bind to cells after joining with an antibody). |
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Chapter 7. A macrophage eats a pathogen coated with antibodies. Are we dealing with innate immunity or cell mediated immunity?
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Humoral immunity.
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Chapter 7. Antibodies can recognize small parts of a protein (say, 5 amino acids) on a larger protein. Will they still recognize these 5 small amino acids if they are floating freely in solution? Why not?
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No, because these five free amino acids may fold in a way unidentifiable for the antibody.
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Chapter 7. There are two types of B cells produced when immature B cells reach maturity? What are they and what do they do?
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Plasma cells and memory cells.
When an antigen binds to the antibody (which is bound to all immature B cell clones), the B cell is stimulated to proliferate to form plasma cell and memory cells. |
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Chapter 7. What is the difference between primary immune response and secondary immune response?
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Primary immune response occurs when the body first encounters the disease antigen and mounts a humoral immune response. Mature B cells are generated but not fast enough to prevent symptoms. In the secondary immune response, the body mounts a much faster and stronger immune response, since the humoral immune system already recognizes the antigen and symptoms never develop.
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Chapter 7. What are the two types of T cells and what do they do?
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1) Cytotoxic T cells recognize pathogens and kill them.
2) Helper T cells activate B cells, T kill cells and other cells of the immune system via secretion of special hormones called lymphokines and interleukins. |
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Chapter 7. What do cytotoxic T cells kill and how are these T cells produced?
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Cytotoxic T cell kill abnormal host cells including:
1) Virus infected host cells. 2) Cancer cells. 3) Foreign cells such as the cells of a skin graft by an incompatible donor. Cytotoxic T cells are produced in the bone marrow before childhood. Trillions of these T cells are made, each specific for an antigen, which the T cell binds to via the T cell receptor. |
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Chapter 7. Do all T cells produced before childhood end up surviving?
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No. Some T cells are specific to the cells of the host. Hence, they are sent to the thymus to be destroyed. Billions of the trillions of T cells produced end up this way.
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Chapter 7. Which class of cells have MHCI complexes? What about MHCII complexes?
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All nucleated cells (no RBCs or platelets) have MHCI complexes.
All cells can randomly pick up peptide components inside the cell and present it on the MHCI complex, which is constantly scanned by T KILLER cells in the body. If it contains viral components, the cell will display it on its MCHI, and when the T KILLER cells scan and recognize it, it will proliferate. MHCII complexes are only seen on antigen presenting cells, usually the B cells or the macrophages. Once these lymphocytes phagocytose pathogens, they chop them up and display pieces of the pathogens on their MHCIIs for the T helper cell to detect. After detection, the T helper cells stimulate the production of B cells and T killer cells specific for the pathogen's antigen. |
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Chapter 7. The cells that give rise to all the different types of blood cells are called ______.
What is the main site for the destruction of aged RBCs? Where do T cell mature? |
Bone marrow stem cells.
The spleen. The thymus, which shrinks in size as a person gets older. |
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Chapter 7. How are white blood cells circulated throughout the body?
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They escape from the the circulation into the interstitial fluid through the intercellular clefts via ameboid motility. Then they are returned to general circulation via lymphatic flow, stopping at lymph nodes en route.
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Chapter 7. Are fats, proteins, and RBCs all circulated inside the lymph vessels?
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No. RBCs do not circulate inside the lymph vessels, but fats and proteins do.
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Chapter 2. What is osmostic pressure?
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Osmotic pressure is the pressure that must be applied to a solution to prevent the inward flow of water across the semipermeable membrane.
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Chapter 7. Does the variable region of an antibody consist of the light chain only?
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No, the variable region consist of both the light and heavy chains.
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Chapter 8. What are the four main excretory organs in the body? What kind of wastes does each deal with? What are the main functions/responsibilities of each?
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1) Kidney-hydrophilic wastes. Also responsible for selective re-absorption of useful compounds. Kidneys has the responsibility of regulating concentrations of certain compounds at optimum levels.
2) Colon-re-absorbs water and ions from the feces. Colons can also excrete ions into feces via active transport. 3) Skin-excretes sweat, which contains water, ions, and urea. 4) Liver-Synthesizes urea (carrier of excess nitrogen breakdown). Liver also deals with large hydrophobic waste products (that can't be dealt with by the kidneys) by chemically modifying them and releasing them into bile. |
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Chapter 8. What two physiological variables do the kidneys maintain in the body?
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1) pH.
2) Fluid volume. |
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Chapter 8. The three goals of the kidney: excreting hydrophilic wastes and maintaining optimum blood pH and fluid volume are achieved through what 4 steps?
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1) Filtration-blood is pushed through a filter, which only allows water and small molecules to be squeezed into the renal tubule.
2) Selective re-absorption. 3) Secretion-can increase the rate at which a certain substance is eliminated from the body, as they are added to the filtrate AFTER blood has been filtered. Last additional step for synthesizing urine: concentration and dilution involving the selective re-absorption of water in deciding whether to make dilute or concentrated urine. |
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Chapter 8. What are the two sphincters that control the release of urine from the bladder?
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1) Internal sphincter-made of smooth muscle. This sphincter relaxes reflectively when the bladder is filled with urine.
2) External sphincter-made of skeletal muscle. A person releases urine consciously when he relaxes this sphincter. |
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Chapter 8. What are the two main anatomical sections of the kidney?
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1) Medulla-the interior portion of the kidney that ha a salt/osmolarity gradient which increases as one goes deeper into the medulla.
2) Cortex-the outer portion of the kidney. |
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Chapter 8. The functional unit of the kidney is the ______, which is split into two main regions, which are ______ and _____.
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Nephron.
1) Capsule. 2) Renal tubule. |
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Chapter 8. Where on the nephron does each of these events take place?
1) Filtration. 2) Selective re-absorption. 3) Urine concentration/dilution. |
1) Capsule.
2) Renal tubule. 3) Collecting ducts. |
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Chapter 8. Where on the nephron would blood vessels be in proximity?
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All over the nephron. This ensures that filtration of blood and selective re-absorption can occur.
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Chapter 8. What substances are ALWAYS reabsorbed at the renal tubule?
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1) Water.
2) Salts. 3) Nutrients. 4) Amino acids. 5) Phosphates. |
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Chapter 8. What is the name of the filter in the nephron? What forces the process of filtration to occur?
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1) Glomerular basement membrane = filter in nephron.
2) Constriction of the efferent arteriole and the ensuing high pressure in the glomerulus causes the filtration to occur. |
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Chapter 8. Can glucose pass through the filter in the nephron?
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Yes.
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Chapter 8. Where does the lion's share of the re-absorptions occur in the nephron? What does the re-absorption of small molecules in this region always accompanied by?
Is the re-absorption of compounds in this region more or less regulated than re-absorption in the distal convoluted tubule? |
In the proximal convoluted tubule (AKA the PCT)
The re-absorption of water. The re-absorption of compounds in this region is less regulated than the re-absorption that occurs in the DCT (which are largely controlled by hormones). Re-absorption in the PCT, however, is still selective. |
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Chapter 8. Where can secretion occur within the renal tubule? Where along the renal tubule does secretion occur the most?
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Secretion can occur everywhere along the renal tubule, but most of it happens in the DCT and the collecting ducts.
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Chapter 8. The part of the nephron that controls urine volume and osmolarity, named _____, includes the ______ and _______ of the renal tubule. This region of the nephron is controlled by two hormones, namely, ____, and _____.
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Distal nephron.
Collecting ducts, and DCT. ADH and aldosterone. |
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Chapter 8. What does ADH do? When is it needed?
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ADH, AKA vasopressin, is released by the posterior pituitary during times of dehydration and low blood volume (high salt concentrations). It functions by making the walls of the distal nephron permeable to water. Water will leave the tubule following this due to the high osmolarity of the medulla.
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Chapter 8. When is aldosterone needed and what does aldosterone do?
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Aldosterone is released during the times of low blood pressure. Aldosterone functions by triggering the reabsorption of salts, which raises the blood osmolarity, and thus blood pressure.
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Chapter 8. What do ADH and aldosterone cooperate to treat, ultimately?
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Low blood pressure.
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Chapter 8. The descending limb of the Loop of Henle is thin or thick walled? What about the ascending limb of the Loop of Henle?
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The Ascending limb of the Loop of Henle is thick and thin walled, while the descending limb of the Loop of Henle is thin walled.
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Chapter 8. The descending Loop of Henle is permeable to only ______. What about the ascending Loop of Henle?
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The descending Loop of Henle is permeable to only water. The ascending Loop of Henle is only permeable to salts and actively transports these compounds out of the filtrate.
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Chapter 8. What are some examples of the kinds of compounds that are secreted in from the blood vessels into the nephrons AFTER filtration has occurred?
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Potassium ions hydrogen, calcium ions, and soluble drugs.
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Chapter 8. How is the Loop of Henle a countercurrent multiplier?
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The Loop of Henle works as a countercurrent multiplier by making the medulla very salty. This facilitates water re-absorption from the collecting duct.
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Chapter 8. What is the mechanism of action of JG cells in response to the detection of low blood pressure? Why is the maintenance of a certain level of blood pressure important for the kidney?
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JG cells, once they detect a lower than normal blood, pressure, release renin into the bloodstream, which stimulates the conversion of angiotensinogen into angiotensin I. Angiotensin I is converted to angiotensin II via ACE enzyme in the lungs.
Angiotensin functions by immediately triggering vaso-constriction and the release of aldosterone, which in turn increases blood osmolarity and triggers ADH release (which triggers water retention and increase of blood volume). |
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Chapter 8. JG cells can respond to what two things?
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1) Decrease of urine osmolarity in distal tubule.
2) Decrease in blood pressure. |
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Chapter 8. How does the body deal with a lowered urine osmolarity in distal tubule?
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When urine osmolarity goes down, it typically indicates a decreased rate of filtration. This incident is detected by the masa densa cells, which immediately stimulate the JG cells to release renin, causing a general vaso-constriction of blood vessels. Masa Densa cells then trigger the relaxation of afferent arterioles, thereby increasing filtration rate.
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Chapter 8. How does the kidney regulate blood pH? What enzyme is involved? Is this process fast or slow? What is the other organ that can regulate blood pH?
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Kidneys can regulate pH by either excreting bicarbonate or hydrogen ions, depending on whether pH needs to be raised or lowered. Carbonic anhydrase is typically involved. Renal regulation of blood pH is slow and can take days.
The lung is also involved in regulating blood pH. By exhaling CO2, the lungs are able to remove an acid from the blood, thus raising blood pH. Respiratory adjustments to blood pH is fast, taking just a few minutes to take effect. |
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Chapter 8. What is the only hormone that is secreted by the kidney?
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EPO.
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Chapter 8. What are the four hormones that affect the kidney? Where are these hormones made? What do these hormones do?
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1) Aldosterone-secreted from the adrenal cortex.
2) ADH-secreted from the posterior pituitary. 3) Calcitonin: secreted from the C cells in the thyroid. They serve to reduce calcium levels in the blood by 1) bone deposition 2) urine excretion and 3) reduced absorption by the gut. 4) Parathyroid hormone: secreted from the parathyroid gland. These hormones have opposite functions to that of calcitonin. |
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Chapter 8. What type of cells typically line the lumen of the GI tract?
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Epithelial cells.
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Chapter 8. Special secretory activity of the GI tract is achieved through what type of cells?
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Epithelial.
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Chapter 8. What are two ways that GI smooth muscle is similar to cardiac muscle? Does the GI tract have a nervous system? If so, what is it called? How is GI motility controlled?
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GI smooth muscle is similar to cardiac muscle because: 1) GI smooth muscle is a functional syncytium (one cells action potential can spread to other cells) and 2) GI smooth muscle can contract without external stimulation, due to spontaneous depolarization.
The GI tract has a nervous system called the enteric nervous system. GI motility is controlled by either the parasympathetic nervous system, which increases motility and forces the sphincters to relax, and hormonal input. |
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Chapter 8. What two purposes does peristalsis serve? What are the two muscles that control peristalsis?
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Peristalsis serves to move food down the GI tract and to mix food.
The longitudinal and circular muscles. The circular muscles contract to prevent food from moving backwards. The longitudinal muscles contract (after the circular muscles) to move food forwards by shortening the the region of the GI tract that contains the bolus. |
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Chapter 8. What are the five layers of tissue that line the intestine starting from the lumen?
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1) Mucosa-epithelial tissue with microvilli.
2) Submucosa-connective tissue and blood supply. 3) Circular muscularis. 4) Longitudinal musclaris. 5) Serosa-connective tissue. |
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Chapter 8. GI secretions are stimulated by the _______ and ______ and inhibited by _______.
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GI secretions are stimulated by the presence of food in the GI tract and the parasympathetic nervous system, and inhibited by the sympathetic nervous system.
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Chapter 8. Most exocrine secretions come from which organs? Is it possible to have exocrine secretions from non-organs?
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1) Pancreas.
2) Liver. 3) Gallbladder. Yes, you can have exocrine secretions from specialized epithelial cells such as the gastric cells in the stomach that secrete pepsinogens and goblet cells throughout the entire GI tract that secrete mucous. |
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Chapter 8. Where does water re-absorption occur in the GI tract?
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Water re-absorption occurs in the small and large intestines.
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Chapter 8. What are the exocrine and endrocrine cells of the pancreas?
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The exocrine secreting cells are called pancreatic acinar cells.
The endocrine secreting cells are collectively called the Islet of Langerhans. |
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Chapter 8. What are the three digestive functions of the mouth?
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1) Fragmentation.
2) Lubrication. 3) Some enzyme digestion |
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Chapter 8. What are the enzymatic secretions of the mouth?
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1) Salivary amylase-breaks down starch down to disaccharides.
2) Lingual lipase-breaks down fats. 3) Lysozyme-attacks bacterial cell walls. |
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Chapter 8. What are the two muscular rings that regulate the movement of food through the esophagus?
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1) Upper esophageal sphincter-located near the top of the esophagus.
2) lower esophageal sphincter-located near the bottom of the esophagus and is important in preventing acid reflux. |
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Chapter 8. What are the three functions of the stomach?
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1) Partial digestion of food.
2) Destruction of microorganisms. 3) Regulate the release of food into the small intestine. |
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Chapter 8. What are the three effects of the high acidity of the stomach?
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-HCl is secreted by the parietal cells lining the stomach.
1) Destruction of microorganisms. 2) Acid-catalyzed hydrolysis of many dietary proteins. 3) Conversion of pepsinogen to pepsin. |
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Chapter 8. What secretes the zymogen pepsinogen? What does pepsin do?
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The chief cells of the stomach. Pepsin catalyzes proteolysis.
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Chapter 8. What sphincter prevents early entry of food from the stomach into the SI? How is the opening and closing of this sphincter controlled?
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Pyloric sphincter, which is controlled hormonally (by CCK, which is secreted in an endocrine fashion by the duodenum of the small intestine) and by nerves between the SI and stomach.
Excess acidity and stretching prevents the pyloric sphincter from relaxing. |
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Chapter 8. Where is gastrin secreted? What does it do (three things)? How is gastrin secretion regulated?
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Gastrin is secreted by the G cells that are located in the walls of the stomach. It stimulates acid secretion (by stimulating histamine secretion, which binds to parietal cells), pepsin secretion, and gastric motility.
Gastrin secretion is stimulated by the parasympathetic nervous system and the presence of food in the stomach. |
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Chapter 8. Where does digestion start and end? What about absorption?
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Digestion starts in the mouth and ends in the duodenum and jejunum.
Absorption begins in the duodenum and continues throughout the entire small intestine. |
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Chapter 8. What are three important structures in the villi of the SI?
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1) Capillaries-carries monosaccharides and amino acids. The capillaries merge to form the hepatic portal vein, which carries the nutrients from the gut to the liver.
2) Small lymphatic vessels called lacteals, which transport dietary fats to the thoracic duct, which empties into the bloodstream. 3) Peyer's Patches-parts of the immune system that monitors the gut for pathogens. |
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Chapter 8. What are the two ducts that empty into the duodenum?
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The common bile duct and the pancreatic duct.
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Chapter 8. What are the two functions of bile?
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1) A vehicle of waste excretion for the liver.
2) Emulsification of fats. |
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Chapter 8. Bile acids are re-absorbed in the _____. What class of drugs prevent this from happening?
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Bile acids are re-absorbed in the ileum. Bile acid sequesterents prevent this from happening.
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Chapter 8. What are the three enzymes that are secreted by the duodenum?
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1) Enterokinase-activates the pancreatic zymogen trypsinogen to trypsin.
2) Brush border enzymes-Hydrolyze disaccharides and proteins into monosaccharides and amino acids. |
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Chapter 8. What are the three hormones secreted by the small intestine? What are they secreted in response to? What does each hormone do?
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1) CCK-secreted in response to fats in the duodenum. CCk causes the pancreas to secrete digestive enzymes, stimulate the gall bladder to release bile, and decrease gastric motility.
2) Secretin-secreted in response to acid in the duodenum, which stimulates the pancreas to secrete water and bicarbonate to neutralize the acid. 3) Enterogasterone-decreases stomach emptying. 2) |
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Chapter 8. True or false and explain: when a pancreatic cell secretes an alkaline fluid into the gut, the pH within the cytoplasm of that pancreatic cell must decrease.
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True, because carbon dioxide is converted to carbonic acid via carbonic anhydrase. carbonic acid dissociates into bicarbonate and a proton. After the bicarbonate is secreted, only the proton is left behind, thus lowering the pH of the cytoplasm.
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Chapter 8. What are the main responsibilities of the large intestine? Where does the LI begin and end? What are the two sets of muscles that control defecation?
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Water and mineral absorption. The LI begins with the cecum and ends with the rectum.
Defecation is controlled by two sets of muscles of the anal sphincter. The first set is an internal layer of smooth muscle that's controlled autonomically and the second set is the outer layer of skeletal muscle controlled voluntarily. |
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Chapter 8. Colonic bacteria are usually what kinds of anarobes? What two purposes do they serve?
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Colonic bacteria are usually facultative or obligate anaerobes.
They serve to outcompete harmful pathogens for space and supply us with vitamin K, which helps in blood clotting. |
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Chapter 8. What are the four accessory digestive organs?
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1) Liver.
2) Pancreas. 3) Large salivary glands. 4) Gall bladder. |
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Chapter 8. Which of the four main biological macromolecules can enzymes of the pancreas digest?
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All four.
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Chapter 8. What hormone is secreted with aims to stimulate secretion of pancreatic enzymes?
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CCK.
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Chapter 8. What cells are responsible for secreting glucagon? What does glucagon do?
What cells are responsible for secreting insulin? What does insulin do? Somatostatin? |
Alpha cells secrete glucagon, which raise blood sugar levels by stimulating the liver to hydrolyze glycogen and also stimulate adipocytes to release fats into the bloodstream.
Beta cells secrete insulin to raise blood sugar levels. Insulin stimulates the removal of glucose from the bloodstream to be stored as glycogen and fat. Gamma cells of the pancreas secrete somatostatin, which inhibits certain digestive processes. |
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Chapter 8. There are three hormones that can raise blood glucose. What are they?
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1) Epinephrine.
2) Glucagon. 3) Cortisol. |
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Chapter 8. What are two ways that pancreatic secretions can be controlled?
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1) Parasympathetic nervous system.
2) CCK and secretin. |
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Chapter 8. What are two ways the gallbladder can be controlled?
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1) CCK
2) Parasympathetic nervous system. |
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Chapter 8. The liver receives two blood supplies. What are they?
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1) Oxygenated blood from the hepatic arteries.
2) Venous blood from the hepatic portal systems. |
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Chapter 8. In response to low sugar levels in the blood, the liver stimulates glycogen breakdown and ______.
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Gluconeogenesis.
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Chapter 8. What are the two types of tissue that are capable of storing glucose as glycogen and subsequently breaking down glycogen when glucose is needed?
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1) Muscle.
2) Liver. Only the liver can release free glucose into the bloodstream, as only the liver has the enzyme necessary to convert glucose-6-phosphate (what you get from glycogen breakdown) to glucose. |
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Chapter 8. How are lipid and protein metabolism handled in the liver? You already know carb metabolism in the liver....
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-Protein metabolism: nitrogenous bi-products and ammonia are transported to the liver, where these compounds are converted to urea, which is excreted with urine.
-Lipid breakdown: fats exit the intestines and enter lymphatic vessels in molecules called chylomicrons, which are degraded by lipases into triglycerides, glycerol, and chylomicron remnants. These particles are combines with proteins into lipoproteins by hepatocytes in the liver. |
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Chapter 8. The majority of plasma proteins are made where?
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Liver.
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Chapter 8. Monosaccharides are transported into the bloodstream via active transport or facilitated transport?
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Monosaccharides pass from the intestinal lumen into the epithelial cells lining the lumen via secondary active transport. It exits the epithelial cells and enters the bloodstream via facilitated transport/diffusion. The ion that themonosaccharides are co-transported with is Na+. The intercellular concentration of Na+ is re-established by the Na+/K+ pump.
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Chapter 8. Where does protein digestion begin in the digestive tract?
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In the stomach.
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Chapter 8. What is the function of trypsin? What is the final enzyme in the digestive pathway of proteins that gives amino acids as the product?
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The function of trypsin is to activate other pancreatic digestive enzymes, most of which are proteases.
Brush border peptidases breakdown dipeptides and tripeptides into amino acids. |
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Chapter 8. The movement of proteins/protein components (AAs) through the epithelial cells that line the small intestine is similar to the movement of what other type of nutrient?
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Carbs. Amino acids enter the cells via co-transport and leave the cell into the bloodstream via a uniporter.
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Chapter 8. The pancreatic lipases can only go to work on far particles after ______. How are fat particles transported into the epithelial cells that line the SI and enter the bloodstream?
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Pancreatic lipases can only do their job once CCK has stimulated the release of bile, which emulsifies the fats into tiny micelles, which are viable for pancreatic lipases. The pancreatic lipases hydrolyze the fats into monoclycerides and free fatty acids. These products of hydrolysis can freely enter the epithelial cells.
Once inside the epithelial cells of the SI, these monoglycerides and free fatty acids are re-packaged into triglycerides and into chylomicrons to allow its diffusion into the bloodstream. Note that the chlyomicrons enter lacteals and circulate the lymphatic systems before they can enter the general blood circulation. Chylomicrons can be taken up into the liver by being broken down into monglycerides and free fatty acids. Once inside, they are re-made into triglycerides and stored. |
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Chapter 9. What are the two types of striated muscle in the body?
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Cardiac and skeletal muscle.
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Chapter 9. Muscles are connected to the ones via ______. Can muscles expand AND contract?
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Muscles are connected to the bones via tendons (strong connective tissue). Muscles can only contract, not expand.
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Chapter 9. How do we determine the insertion and origin of skeletal muscle?
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The insertion is the site the site where the muscle attaches to that's more distant to the body's midline. The origin is the sits of attachment fora muscle that's closer to the body's mid-line.
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Chapter 9. All skeletal muscle use what neurotransmitter?
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ACh.
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Chapter 9. A bundle of muscle cells is called _______, and these muscle cells are held together by _______ tissue.
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Fascicle. Connective tissue.
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Chapter 9. One muscle fiber consists of _____ muscle cell. Each muscle cells has one or multiple nuclei/nucleus? How many nerve endings innervate each muscle fiber?
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1. Each muscle fiber has multiple nuclei. Each muscle fiber is innervated by one nerve ending.
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Chapter 9. Each muscle fiber has a cell membrane called ______, which consists of ____, _____, and _____. Within each muscle fiber there are many smaller units called ____, which look like ____ and function to ______.
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Sarcolemma, which consists of the plasma membrane, plus an additional layer of polysaccharide and collagen.
Myofibrils, which give the striated appearance to skeletal muscle and provides the contractile force in skeletal muscle. |
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Chapter 9. The individual contractile unit within a muscle is the ______.
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Sarcomere, which make up the myofibril.
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Chapter 9. What are the I and A bands in the sarcomere?
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I bands are the region in the sarcomere that consists of thin filaments.
The A bands represents the full length of the thick filament. The H band consists of the region |
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Chapter 9. Individual sarcomeres are separated by ______ lines in muscle.
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Z lines.
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Chapter 9. Why is ATP needed in a contractile cycle in muscle?
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ATP is needed for the myosin head to be released from the actin thin filaments.
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Chapter 9. All ATP related reactions require what co-factor?
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Magnesium.
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Chapter 9. The contractile cycle can occur spontaneously in muscle. How is muscle contraction regulated?
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The troponin-tropomyosin complex is needed. The tropomyosin is a long protein that winds around the thin filaments, blocking all the myosin head regions, thus preventing contraction. It is only when troponin (conformational change) attached to calcium that tropomyosin moves out of the way.
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Chapter 9. What molecule has the ATPase activity in regards to muscle contraction?
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Myosin.
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Chapter 9. Describe the structure of the neuromuscular junction (NMJ).
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The NMJ consists of a long invagination of the muscle cell's cell membrane, which is filled by the axon terminus of the neuron that the muscle synapses with. This allows a large region of the muscle cell to become depolarized at once.
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Chapter 9. As an action potential arrives at the axon terminus, _____ gated ion channels open, releasing _______, which in turn triggers the ______.
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-Ca++ voltage gated channels.
-Ca++. -The resulting influx of Ca++ causes the exocytosis of vesicles containing ACh. |
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Chapter 9. ACh will continue to depolarize the post synaptic cell until ____ destroys the NT.
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ACh-ase.
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Chapter 9. When threshold is reached in the post-synaptic cell, what channels are opened?
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Na+ voltage gated channels.
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Chapter 9. How can an entire muscle fiber be depolarized? (contraction only occurs if the ENTIRE muscle fiber is depolarized beyond threshold)
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T-tubules, which are deep invaginations of the cell membrane.
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Chapter 9. What structure is needed to ensure that large amounts of calcium is present in the muscle cell when the depolarization signal is present?
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Sacroplasmic reticulum, which are specialized smooth ER that enfolds each myofibril in the cell. It has voltage gated Ca++ channels which allow it to release Ca++ when a depolarization signal reaches the muscle. Ca++ is sequestered after an AP via active transport back into the SR>
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Chapter 9. The smallest measurable muscle contraction is known as the ______. The nervous system, can increase the force of contraction in what two ways?
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1) Motor unit recruitment: Activating more motor neurons, which can innervate more motor units. (One motor unit = group of myofibers innervated by the branches of a single motor neuron's axon).
2) Frequency summation: A rapid repeated series of stimulations builds on the amount of Ca++ released by the SR, thus increasing the intensity of the contraction. |
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Chapter 9. The skeletal muscle action potential has a refractory period just like a neural refractory period. If that is the case, how are frequency summations possible?
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in frequency summation, two consecutive APs must be longer tan the refractory period but shorter than the amount of time needed to actively transport the released Ca++ back into the SR.
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Chapter 9. Why is creatine phosphate important in muscle contraction?
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Creatine phosphate is important in muscle contraction because it creates a ready supply of ATP needed to release the myosin heads from the actin thin filament. The ATP produces via glycolysis and the TCA cycle are not made fast enough to accommodate the needs of muscle. The hydrolysis of creatine phosphate regenerates ATP from ADP and Pi.
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Chapter 9. What is the role of myoglobin in muscle contraction?
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Myoglobin is a globular protein and is similar to one of the subunits of hemoglobin. It takes oxygen from hemoglobin and provides an oxygen reserve for muscles, releasing the gas when it is needed.
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Chapter 9. During anaerobic metabolism, _____ is released and this causes the blood pH to increase or drop? It is then transported to the liver, where it is converted to _____.
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Lactic acid, which drops blood pH. It is eventually transported to the liver, where it is converted to pyruvate.
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Chapter 9. How does rigor mortis occur?
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Rigor Mortis occurs when the ATP supply is completely exhausted and the muscles can no longer contract or relax (myosin heads can no longer release actin).
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Chapter 9. The length tension relationship states that the ideal length for a sarcomere is ______ microns. Skeletal muscles can not take advantage of this fact to optimize contraction because ______. However, ____ muscles are able to do this.
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2.2 microns.
Skeletal muscle cannot take advantage of the length-tension relationship because of its attachment to bones. Cardiac muscles are not bounds by such constraints. |
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Chapter 9. Are the basic mechanisms and regulation of contraction the same in cardiac and skeletal muscle? Is cardiac muscle striated? Is cardiac muscle composed of multinucleated cells?
|
Yes, you still have the thin and thick filaments organized into sarcomeres for contraction, T-tubules for AP propagation, and troponin-tropomyosin complexes for regulation.
Cells of cardiac muscles are not multinucleated and are striated in appearance due to the organization of the sarcomeres. |
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Chapter 9. Does cardiac muscle contraction depend on motor neurons? What is the main nerve that controls cardiac muscle contraction? What NS do the nerve endings use? Are the signals inhibitory or stimulatory? What stimulates the contraction of cardiac muscle?
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No. Vagus nerve, which uses ACh to regulate cardiac muscle contraction in the heart in an inhibitory fashion. The pacing of the sinatrial node (resulting from spontaneous depolarizations) is what stimulates cardiac muscles to contract.
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Chapter 9. What is the difference between the APs of skeletal and cardiac muscle?
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Cardiac muscle have an additional voltage gated Ca++ channels with the voltage gated Na+ channels. These Ca++ voltage gated channels respond more slowly to threshold depolarization and take longer to close. This gives the plateau phase in the cardiac muscle AP. The longer time of contraction allows for better ventricular emptying, and a longer refractory period, making summation and tetanus impossible.
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The length-tension relationship is most significant in what type of muscle? Why?
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The length-tension relationship is most significant in cardiac muscle, because any kind of stretching that falls short of the optimum level of stretch results in decreased contractile strength and decreased ejection volume, which can lead to death.
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Chapter 9. What are the three things that are similar in skeletal muscle and smooth muscle?
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Both skeletal and smooth muscle have the 4 step contractile cycle, and the actin-myosin filaments to provide the physical mechanism of contraction. Finally, contraction in smooth muscle is initiated by an increase in cytoplasmic Ca++.
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Chapter 9. How are smooth muscle cells connected?
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Smooth muscle cells are connected via gap junctions, just like in cardiac muscle.
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Chapter 9. What structures are missing in smooth muscle that are present in cardiac and skeletal muscle?
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1) Troponin-tropomyosin complex. Smooth muscle is regulated by calmodulin and MLCK enzyme.
2) T-Tubules, because smooth muscle cells are too small to need T-tubules. |
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Chapter 9. Why are smooth muscle cells not striated?
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Smooth muscle cells are not striated because the thin and thick filaments are NOT organized into sarcomeres.
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Chapter 9. Smooth muscle cells rely heavily on _____ for sources of Ca++ for contraction.
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Extracellular Ca++ sources.
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Chapter 9. The smooth muscle action potential varies but depends on ______. Do smooth muscle cells have sodium fast channels?
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Location. Smooth muscle cells have only slow channels, which means that smooth muscle APs take much longer than skeletal muscle APs.
Smooth muscle that must contract for a long time (e.g. those in the uterus) have APs more similar to those of cardiac muscle, but with a less sharp spike. |
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Chapter 9. Smooth muscle are innervated by ______, as in skeletal muscle, but in contrast to the skeletal muscle, these _____ are ______. The spread of action potentials from cell to cell in smooth muscle is more similar to that of cardiac/skeletal muscle cells?
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Motor neurons. Autonomic motor neurons, NOT somatic motor neurons.
The spread of APs from cell to cell in smooth muscle is more similar to cardiac muscle, in which cells are connected to one another in a functional syncytium. |
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Chapter 9. How does an AP actually occur in a smoother muscle cell?
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Smooth muscle cells are all connected to one anther via gap junctions. This allows ions to pass between cells, which forces the resting potential to fluctuate in any one cell. The rhythmic passing of ions from cell to cell causes the changes in the resting potential to propagate like a wave in each cell. These fluctuations in the resting potentials are called slow waves.
In response to certain stimuli, the parasympathetic nervous system release NSs that bind to smooth muscle cells and prime the cells for an AP by raising their membrane potential closer to to the threshold. To reach the full AP, these smooth muscle cells rely on the slow waves to push the membrane potential above the threshold. |
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Chapter 9. Does the contraction of cardiac muscle depend on extracellular Ca++?
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Yes, partially.
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Chapter 9. Most of the voltage gated calcium channels in smooth muscle are located where? What about for skeletal muscle?
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Most voltage gated calcium channels are located on the cell membrane for smooth muscle and on the surface of the SR for skeletal muscle.
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Chapter 9. The vertebrate endoskeleton is divided into two components: the _____ and the ______.
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The axial and appendicular skeleton.
The axial skeleton consists of the skull, vertebral column, and rib cage. Everything else is part of the appendicular skeleton. |
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Chapter 9. Bone is an example of what kind of tissue, which stem from what kind of cell?
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Connective, which stems from fibroblast cells.
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Chapter 9. What are three types of tissue derived from fibroblasts?
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1) Adipocytes.
2) Chondrocytes. 3) Osteocytes. |
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Chapter 9. There are two different types of connective tissue: ____, and ______. Give some examples of each.
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1) Loose connective tissue, which include adipocytes, components of the extracellular matrix, and the basement membrane, which is a sheet of collagen that supports cell layers.
2) Dense connective tissue-which refer to tissue that contains large amounts of collagen, such as bones, tendons, and ligaments. |
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Chapter 9. What are the two bone shapes?
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1) Flat: the location of hemotopoiesis and are responsible for the protection of organs.
2) Long: bones of limbs. The shaft is called the diaphysis and the flared ends are called epiphysis. |
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Chapter 9. The general internal structure of bone may be ___ or _____. The _____ is always surrounded by _____. The diaphysis of long bones only contain the _____ internal structure.
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Spongy or compact. Spongy bone is always surrounded by compact bone. The diaphysis of long bones only contained compact bone.
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Chapter 9. Bone marrow is found in the _____ of long bones and in the ____ in flat bones. What are the two types of bone marrow and what does each type do?
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Bone marrow is found in the shafts of long bones and in the pores of spongy bones.
Red marrow is found in the spongy portion of flat bones. It is the site of hematopoesis. Yellow marrow is found in the shafts of long bones and is filled fat (inactive). |
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Chapter 9. Bone is composed of two principal components: ____ and _____. How are these two things involved in bone synthesis?
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Collagen and hydroxyapatite. During bone synthesis, the collagen is laid down first, then the hydroxyapatite is formed around the collagen framework, giving the structure the strength and inflexibility characteristic of bone.
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Chapter 9. The basic unit of complex bone structure in compact bone is called the ______, AKA _______. Describe this structure.
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Haversian system, AKA osteon. At the very center of the structure is the central canal containing blood and lymph vessels and nerves. Concentric rings of bone called lamellae surround the central canal. Small canals called canaliculi branch out from each central cannal to lacunae, which contains one osteocyte each. There are also Perforating/Volkmann's canals that run perpendicular to the central canal to connect osteons.
Osteocytes have long processes which extend up and down the central canal allowing their connection with other osteocytes via gap junctions. This facilitates the exchange of nutrients and wastes. |
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Chapter 9. What are the three types of cartilage and what are their characteristics?
|
1) Hyaline cartilage: strong and somewhat flexible. This type of cartilage is found in the trachea, larynx, and joints.
2) Elastic cartilage: found in structures that require support and more elasticity that hyaline cartilage can provide. Found in the ear and epiglottis. 3) Fibrous cartilage: very rigid and found in places where VERY strong support is needed. Found in the pubic symphysis and in the intervertebral disks of the spinal column. |
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Chapter 9. How does cartilage receive materials needed for its survival and metabolism?
|
Cartilage is not innervated by nerves nor fed by arteries. It receives its essential materials from the surrounding fluid.
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Chapter 9. Tendons connect ____ with _____. What about ligaments?
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Tendons connect muscle with bone. Ligaments connect bone with bone.
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Chapter 9. Movable joints are lubricated by _____, which is kept within the joint by ______. The surfaces of the two bone that make contact with each other are lined by _____.
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Synovial fluid, which is kept within the joint by the synovial capsule.
The surfaces of two bones that make contact are lined with articular (hyaline) cartilage, which guarantees perfectly smooth movement. |
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Chapter 9. Most bone formation is achieved via _____.
|
Endochondral ossification, in which cartilage is laid first, then replaced by bone.
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Chapter 9. Flat bones are often made via what process. What is the starting materials usually?
|
Intramembranous ossification. Starting material is usually mesenchyme.
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Chapter 9. Outline the process of long bone formation.
|
During childhood, the epiphyseal plate is located between the diaphysis and epiphysis. Chondrocytes in the epiphyseal plate are actively producing hyaline cartilage, which elongates the bone and pulls the epiphysis and diaphysis apart. The cartilage is eventually replaced by bone, and since ossification occurs more rapidly than cartilage formation, eventually the epiphysis will meet the diaphysis. When this occurs, long bones can no longer lengthen. The epiphyseal line refers to the point where the ossification of from the diaphysis end meets the ossification from the epiphysis end.
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Chapter 9. Bone in adults is constantly being ______. What kind of cells do this? What are the cells that replaced old bone called?
|
Remodeled.
Osteoclasts destroy old bone and osteoblasts synthesize new bone. Osteoblasts synthesize bone until they're surrounded by bone, making them osteocytes. |
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Chapter 9. The bone destroyed by osteoclasts go where? What regulated the level of Ca++ and phosphate levels in the blood? What regulated the amount of Ca++ and phosphate in the blood?
|
The bone destroyed by osteoclasts liberates calcium which goes into the bloodsteam.
The level of osteoclast and osteoblast activity is controls the amount of free calcium and phosphate in the blood. This is regulated by the hormones calcitonin, PTH, and calcitrol. |
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Chapter 9. What are the effects of PTH, calcitrol, and calcitonin on the bones?
|
Calcitrol and PTH: stimulates osteoclast activity.
Calcitonin: inhibits osteoclast activity. |
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Chapter 9. How is calcitriol made?
|
Calcitriol is derived from vitamin D from the kidney.
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Chapter 9. What are the effects of calcitriol, PTH, and calcitonin on the kidneys?
|
PTH: increases reabsorption of calcium.
Calcitriol: increases reabsorption of phosphorous. Calcitonin: decreases reabsorption of calcium. |
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Chapter 9. What are the effects of PTH, calcitriol, and calcitonin on the intestines?
|
PTH: stimulates the formation of calcitriol to indirectly increase intestinal calcium absorption.
Calcitriol: increases intestinal absorption of calcium. |
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Chapter 10. The simple movement of air into and out of lungs is called ______. The process of gas exchange is called ______.
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-Movement of air into and out of lungs = ventilation.
-Process of gas exchange: respiration. |
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Chapter 10. The parts of the respiratory system that participate only in ventilation are referred to as the _____. What about structures that participate only in respiration?
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-Conduction zone = parts of the respiratory system that participate only in ventilation.
-Respiratory zone = parts og the respiratory system that participate only in respiration. |
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Chapter 10. Other than gas exchange, what are three other functions of the respiratory system? How exactly is each function achieved?
|
1) Protection from pathogens: mucociliary elevators and macrophages help in this.
2) pH regulation: pH can be raised during breathing because carbonic acid is expelled from the blood as carbon dioxide is exhaled. 3) Thermoregulation: breathing decreases body temperature. |
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Chapter 10. Inhaled air follow what pathway? Which parts are part of the conduction and respiratory zone?
|
Nose--> nasal cavity--> pharynx--> larynx--> trachea--> bronchi--> terminal bronchioles--> respiratory bronchioles-->alveolar ducts--> alveoli.
Everything up to terminal bronchioles are part of the conduction zone. Everything after that is part of the respiratory zone. |
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Chapter 10. The walls of bronchioles are made of _____, why? Can gas exchange occur at the walls of terminal bronchioles? Why or why not?
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Smooth muscle, so that their diameters can be regulated to adjust airflow into the system.
Gas exchange cannot occur at the walls of the terminal bronchiole, because the smooth muscle is too thick. |
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Chapter 10. What two crucial structures are located in the larynx?
|
1) Epiglottis.
2) Vocal cords. |
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Chapter 10. The alveolar duct is mad completely out of _______. The respiratory bronchiole differs from the terminal bronchiole in one aspect, which is ____.
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Alveola.
The respiratory bronchiole has alveola scattered throughout its walls, which is made of smooth muscle. |
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Chapter 10. The entire pathway of the respiratory system is lined with _______ cells, and what type of ____ cells specifically?
|
Tall, columnar epithelial cells, some of which are specialized to secrete a sticky mucous and other have cilia which sweep pathogens out towards the pharynx.
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Chapter 10. The epithelial cells that line the cells in the respiratory zone of the respiratory system are what kind of epithelial cells?
|
Simple squamous epithelial cells. They do not have cilia or have the ability to secrete mucous. This calls for the presence of alveolar macrophages that patrol the alveolus in search for pathogens.
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Chapter 10. What substance coats the alveoli to prevent it from collapsing due to water's surface tension?
|
Surfactant, which ecreae surface tension and are secreted by the fat, cuboidal epithelial cells that also line the alveolus. These cells are NOT the principle cells that line the alveolus. d
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Chapter 10. How are the lungs prevented from collapsing on itself inside the chest cavity?
|
The lungs are surrounded by two membranes: the parietal pleura (which line the inside of the chest cavity) and the visceral pleura (which line the surface of the lungs).
Between the two pleuras is a pleural space. The pressure in this space is negative, so the two membrane are drawn tightly against each other in a vacuum, and keeps the surface of the lungs drawn up against the inner surface of the chest wall. |
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Chapter 10. Inhalation is an active/passive process and what muscles (if needed) are contracted during this process?
|
Inhalation is an active process and requires muscle contraction.
1) Diaphragm. 2) Intercostal muscles between the ribs forces the ribs to elevate, further expanding the chest cavity. |
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Chapter 10. How does chest expansion bring about lung expansion as well?
|
The negative pressure in the pleural space.
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Chapter 10. Is exhalation a passive or active process. If it is active, what muscles are involved?
|
Exhalation is both a passive process and passive process. When the intercostal muscles and diaphragm relax, the chest cavity and lung volume become smaller, forcing air out into the atmosphere.
The abdominal muscles are needed if a forceful exhalation is required. The contraction of these muscles further shrinks the volume of the lungs, forcing even more air out. |
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Chapter 10. The pressure in the pleural space and in the alveolus become more negative or positive during inhalation?
|
The pressure in the pleural space and alveolus become more negative during inhalation.
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Chapter 10. When is the alveolar pressure equal to zero (equal to the atmospheric pressure?)
|
1) At the end of resting expiration and before another inspiration begins.
2) Just after inspiration, and before expiration begins. |
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Chapter 10. Define the following terms:
1) Tidal volume: 2) Expiratory reserve volume: 3) Inspiratory reserve volume: 4) Functional reserve capacity: |
1) Tidal volume: the amount of air that moves in and out during normal light breathing.
2) Expiratory reserve capacity: the amount of air that can be expelled after a passive resting expiration. 3) Inspiratory reserve volume: the volume of air that can be inspired after a relaxed inspiration. 4) Functional residual capacity: the amount of air left in he lungs after a relaxed expiration. |
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Define the following terms:
1) Inspiratory capacity: 2) Residual volume: 3) Vital capacity: 4) Lung capacity: |
1) Inspiratory capacity: the maximum amount of air that can be inhaled after a relaxed expiration.
2) Residual volume: the amount of air left in the lungs after the strongest expiration. 3) Vital capacity: the maximum amount of air that can be forced out after the deepest possible breath. 4) Lung capacity = vital capacity + residual volume. |
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Chapter 10. In the process of transporting blood from the heart to the lungs, the pulmonary arteries branch out into the _____, and eventually into the ______ when the blood reaches the alveola.
|
Pulmonary capillaries--> alveolar capillaries.
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Chapter 10. Large increases in the left atrial pressure can cause what in the lungs?
What is usually used to prevent this condition from developing? |
Pulmonary edema, which develops with high left atrial pressure as blood plasma is essentially squeezed out of the capillaries and into the surrounding lung tissue.
-Lymphatic vessels are used to prevent pulmonary edema by carrying out the interstitial fluid from the lungs. |
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Chapter 10. When pulmonary edema results, which of the following events are likely to occur?
1) Accumulation of interstitial fluid in the lungs. 2) Fluid accumulation in the alveoli. 3) Decreases oxygenation of the blood due to excess fluid slowing O2 diffusion. |
All three.
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Chapter 10. What is the most abundant gas in atmospheric air?
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Nitrogen.
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Chapter 10. The driving force of gas exchange between the alveoli and the bloodstream is what?
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Difference in the partial pressures within the alveoli and the bloodstream.
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Chapter 10. What is the barrier that gases have to pass through in order to get from the bloodstream to the air and back?
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The respiratory barrier, which consists of the alveolar epithelium, interstitial fluid, and the capillary endothelium.
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Chapter 10. The partial pressure of oxygen gas at the arterial end of the pulmonary capillaries is greater than, equal to, or less than the partial pressure of oxygen gas at the venous end?
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Less than. The arterial end of the pulmonary arteries carries de-oxygenated blood and the venous en carried oxygenated blood!
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Chapter 10. If the partial pressure of water vapor increases in the atmosphere, what would happen to the partial pressures of nitrogen and oxygen?
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Decrease, because total atmospheric pressure has to be the same overall.
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Chapter 10. Respiration is usually controlled by the ______. What are the two types of signals that can affect this control process?
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Respiratory control center, which is in the medulla.
Mechanical and chemical signals affect this control process. -Mechanical: stretching of the lung tissue stimulate stretch receptors that inhibit further excitatory signals from the respiratory control center to the muscles involved in inspiration. -Chemical: periphery chemoreceptors in the aorta and the carotid artery and central chemoreceptors in the medullary respiratory center monitor the partial pressures of oxygen, carbon dioxide, and pH in the blood and CSF (partial pressure of oxygen is not monitored by the central chemoreceptors). |
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Chapter 10. What is a broncho-constriction and what causes it to occur? What opposes this process from occurring?
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A broncho-constriction occurs when the smooth muscle that line the walls of the larger bronchioles and bronchi contract. This contraction can be innervated by the parasympathetic nervous system (ACh) or stimulation of the irritant receptors when the inner lining of the lung is in contact with irritants. It also occurs in allergic reactions when histamines are released.
Epinephrine opposes bronchoconstriction and causes dilation (which happens when the sympathetic nervous system is activated). |
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Chapter 10. The largest organ in the body is the ______, what are its three main functions?
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Skins, which is responsible for:
1) Protecting the body from pathogens. 2) Preventing excessive evaporation of water. 3) Regulating body temperature. |
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Chapter 10. The outermost layer of the skin is the _____, below this layer is the ____,and below this is the _______.
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Epidermis, dermis, hypodermis (layer of fat).
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Chapter 10. The epidermis is composed of ______ cells. These cells are continuously sloughed off and replenished by the _______ via mitosis.
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Stratified squamous epithelial cells. Epidermis cells slough off and are continuously regenerated by the stratum basale.
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Chapter 10.What keeps the outer layer of the skin waterproof and how does this occur?
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As the cells of the epidermis die, they are filled with a thick, hydrophobic substance called keratin, which helps make the skin waterproof.
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Chapter 10. What protects the skin from the damages of UV light?
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The melanin in the epithelial cells of the epidermis, which are made by the melanocytes.
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Chapter 10. What structures are contained in the dermis? All these structures are embedded in a ____ matrix.
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The dermis contains blood vessels, sensory receptors (which convey information about touch, temperature, pressure, and pain to the CNS), sebaceous (oil) glands, sudoriferous (sweat) glands and hair follicles all mixed within a connective tissue matrix.
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Chapter 10. Describe the structures of the sweat/sudoriferous glands. What is it regulated by? What chemicals are contained in sweat?
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The sweat gland is a long tube that originates in the dermis and stretches to the epidermis and ultimately to a pore on the skin.
Sweat contains water, electrolytes, and urea, and sweating serves to lower body temperature. The sweat gland is regulated by aldosterone, which prevents excessive salts from escaping the circulation. |
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Chapter 10. What are the three general mechanisms the body uses to raise temperature in response to cold weather?
What are two less commonly used mechanisms used to conserve heat? |
1) Contraction of the skeletal muscle (shivering).
2) A layer of insulating fat in the subcutaneous tissue prevents heat loss. 3) Constriction of the blood vessels in the dermis (can also occur with the activation of the sympathetic nervous system). (A) Burning special fat called brown adipose tissue, AKA non-shovering thermogenesis. (B) Increase in thyroid hormone, which increases metabolic rate and thus body temperature. |
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Chapter 10.What are two ways that heat can be lost by the body?
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1) Sweating.
2) Vasodilation causes heat loss by conduction. |
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Chapter 10. How can smooth muscle cells (the same post synaptic cell) respond to both inhibitory and stimulatory neural signals?
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The inhibitory and stimulatory neurotransmitters both bind to the same post synaptic cell, but each open different ion channels. The stimulatory NS opens ion channels that result in depolarizing the post synaptic cell while the inhibitory NSs open ion channels that result in hypolarization.
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Chapter 11. What are the two roles of the testes?
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1) Spermatogenesis.
2) Production of male sex hormone. |
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Chapter 11. Where is the site of spermatogeneis within the testes?
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Seminiferous tubules.
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Chapter 11. The walls of the seminiferous tubules are lined by the ______, which function to do what?
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1) Protect and nurture the developing sperm, both physically and chemically.
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Chapter 11. What is one important type of cell found in the testicular interstitium?
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Leydig cells, which are responsible for androgen synthesis.
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Chapter 11. Where do sperm travel after exiting the seminiferous tubule?
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1) Epididymis.
2) Duct deferens. 3) Inguinal canal. 4) Ejaculatory duct. 5) Urethra. |
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Chapter 11. What are the three glands, collectively called the accessory glands of the male sex organ, do?
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1) Seminal vesicles-secretes about 60% of the total volume of semen into the ejaculatory duct. Main component of liquid secreted from seminal vesicles-fructose and other nourishment for sperm.
2) Prostate gland-fructose and a coagulant. 3) Bulbourethral gland-thick, alkaline mucous. |
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Chapter 11. What are the two sources that make the components of semen?
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1) Accessory glands.
2) Testes. |
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Chapter 11. What are the three components fo erectile tissue?
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1) 2 Corpora cavernosa.
2) 1 corpus spongiosum. |
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Chapter 11. What allows for an erection in the male?
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Spongy erectile tissue, which is composed of modified veins and arteries.
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Chapter 11. What are the three stages of male sexual arousal?
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1) Arousal.
2) Orgasm. 3) Resolution. |
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Chapter 11. The three events in the male sexual act are controlled by ______, which responds to ______ and _____.
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Integrating center in the spinal cord, which responds to physical stimulation and the brain.
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Chapter 11. Arousal is dependent on what part of the nervous system? What two parts is it split into?
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Parasympathetic nervous system. Arousal is separated into the two following parts:
1) Erection-involves the dilation of the arteries supplying the erectile tissue, which induces swelling and stops venous outflow. 2) Lubrication-bulbourethral glands secrete a viscous mucous. |
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Chapter 11. Stimulation of what part of the nervous system is required for orgasm?
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Sympathetic nervous system.
Orgasm is split into emission and ejaculation. -Emission-propulsion of sperm and semen into the urethra by contraction of the smooth muscle surrounding the duct deferens and the ejaculatory duct. -Ejaculation: semen of propelled out of the the urethra by rhythmic contractions of the muscles surrounding the base of the penis. |
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Chapter 11. Ejaculation is a reflex reaction caused by ______.
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The presence of semen in the urethra.
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Chapter 11. Resolution is caused by the _____ nervous system and occurs primarily via ______.
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Sympathetic nervous system. It is caused by the constriction of the arteries to the penis so the blood can flow back into the body via the body via the veins.
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Chapter 11. The entire process of spermatogenesis occurs with the specialized aid of the ______.
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Sertoli cells AKA sustenacular cells.
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Chapter 11. Immature sperm arise first at the ______ and move _______ as they gradually mature.
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Immature sperm arise at the walls of the seminiferous tubule and move inwards towards the lumen as they mature.
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Chapter 11. In the process of spermatogenesis, where do the cells start to become haploid?
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Only the primary spermatocyte undergoes meosis. So only cells after the primary spermatocyte state become haploid.
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Chapter 11. What are the five cell types that constitute the five stages of sperm maturation?
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1) Spermatogonium-reproduce itself via mitotic divisions.
2) Primary spermatocyte-undergpes meosis I. 3) Secondary spermatocyte-undergoes meosis II. 4) Spermatid-makes the spermatozoan (mature sperm). Location: inner seminiferous tubule. 5) Spermatozoan-mature sperm. |
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Chapter 11. The final stages of sperm maturation occurs in the ______ (not the inner lumen of the seminiferous tubule).
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Epididymis.
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Chapter 11. When mature sperm first enter the epididymis, are they capable of motility? When are they capable of moving on their own?
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No. Sperm obtain motility only after they've reached the duct deferens from the epididymis. Even then, they are inhibited from moving by inhibitory substances secreted from the duct deferens, which lowers their metabolic rate to conserve energy.
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Chapter 11. Where do the mitochondria in sperm get their energy?
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From the fructose which seminal vesicles contribute to semen and from vaginal secretions.
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Chapter 11. How does sperm penetrate the outer layers of the egg? How does sperm attach to receptors on the zona pellucida of the egg?
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Acrosome, which contains hydrolytic enzymes.
Bindin, a protein on the sperm's surface, attaches to receptors on the outer surface of the egg. |
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Chapter 11. Do eukaryotic sperm cells move via flagellar rotation?
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No, only the tails of prokarotic flagella move via rotation.
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Chapter 11. Testosterone plays a critical role in the stimulation of ______. What about LH? FSH? What hormone (secreted by what source) inhibits FSH release?
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1) Testosterone-division of spermatogonia.
2) LH-stimulates interstitial cells to secrete testosterone. 3) FSH-stimulates the sustenacular Cells. Inhibin is secreted by the sustenacular cells and inhibits FSH release via a negative feedback pathway. |
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Chapter 11. Testosterone, estrogen, progesterone, and inhibin are all hormones which reach the ________ in a negative feedback loop.
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Anterior pituitary and hypothalamus.
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Chapter 11. Early embryos, whether male or female, have undifferentiated genitalia, and possess both ____ and _______ ducts.
What happens in the absence of a Y chromosome? What happens if a Y chromosome is present? |
Mullerian and Wolfian ducts.
In the absence of the Y chromosome, Mullerian duct development occurs by default, and female INTERNAL genitalia results. Female EXTERNAL genitalia develop separately. In the presence of the Y chromosome, the testes develop and cause male internal and external genitalia to develop by producing testosterone and Mullerian inhibiting factor. |
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Chapter 11. Testosterone that is secreted from the testes must be converted to ____ before it can exert its effect.
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Dihydroxytestosterone.
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Chapter 11. What does the Mullerian duct develop into? What does the Wolfian duct develop into?
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The Mullerian duct develops into the female INTERNAL genitalia. The Wolffian duct develops into the male INTERNAL genitalia.
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Chapter 11. Do testes development depend on testosterone?
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No. It will be present with or without testosterone. The male genitalia, however, needs testosterone to fully develop and has receptors for the hormone.
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Chapter 11. What hormone is absolutely necessary for the spermatogenesis? What else is this hormone important for?
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Testosterone, which is also important for the development of male secondary characteristics, pubertal growth spurt, and the fusion of the epiphyses.
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Chapter 11. What are the levels of testosterone in a male throughout his lifetime?
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Before birth testosterone remain at a significant level, and drops off after birth. Testosterone levels arises again at puberty.
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Chapter 11. Why are tumors derived from interstitial cells in boys more easily diagnosed than those derived from grown men?
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The interstitial cells in boys secrete very little testosterone. Hence, abnormal interstitial cells would be easy to spot as the young boy would reach premature puberty.
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Chapter 11. Which has a higher concentration in the bloodstream: testosterone or dihydroxytestosteron?
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Testosterone, as dihydroxytestosterone is produced inside the target cells of testosterone.
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Chapter 11. During puberty and adult life, sex steroid production is controlled by ______ and the ______. What are the pathways of this hormone production mechanism and what are the regulation pathways needed to control production?
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Hypothalamus and anterior pituitary.
The hypothalamus produces GnRH, which acts on the pituitary which releases FSH and LH to the gonad. At the male gonad, LH acts to stimulate interstitial cells to secrete testosterone, and FSH stimulates sustenacular cells. At the female gonad, FSH stimulates granulosa cells to secrete estrogen, and LH stimulates the formation of the corpus luteum and progesteron secretion. Feedback inhibition by the sex steroid hormones inhibits the productionof GnRH and LH and FSH. Inhibin (produced by sustenacular cells in men and by the granulosa cells in females) provide futrher feedback inhibition of FSH production. |
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Chapter 11. What causes the fusion of the epiphysis in females?
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Estrogen.
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Chapter 11. The neck of the uterus which opens into the vagina is called the ________. The innermost lining of the uterus is called the _______. The uterus ends in two _____. Surrounding the endometrium is a layer of _______.
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Cervix. The innermost lining of the uterus is called the endometrium. The uterus ends in two uterine tubes. Surrounding the endometrium is a layer of myometrium, which is smooth muscle comprising the wall of the uterus.
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Chapter 11. In the presence of testosterone, the labioscrotal swellings turn into the _____, what about in the presence of estrogen?
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In the presence of testosterone, the labioscrotal swelling turns into the scrotum and in the presence of estrogen, the labioscrotal swelling turns into the labia minora.
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Chapter 11. What happens to the Wolffian ducts if the fetus is destined to be a female? What about the Mullerian ducts in the presence of testosterone?
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The Wolffian Ducts atrophy is the fetus is determined to be a female.
The Mullerian Ducts regress in the presence of testosterone. |
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Chapter 11. Is estrogen required for the development of the uterus and uterine tubes?
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No, the uterus and the uterine tubes will form by default from the Mullerian ducts as long as mullerian inhibiting factors are not present.
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Chapter 11. What are some differences seen in the male and female sexual acts?
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The male and female sexual acts are mostly the same except the resolution phase in females is longer than that of males, and females require the greater vestibular glands to contribute to lubrication that occurs during arousal.
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Chapter 11. Oogenesis occurs when in female? How does this contrast with spermatogenesis in males?
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Oogenesis occurs only prenatally in females. Spermatogenesis occurs on in males during adulthood.
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Chapter 11. In the female, oogonia are produced via _____ and remain in what stage of meosis until ______. What results from the first meotic division? When does the second meotic division occur? What does the second meotic division result in?
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Oogonia are produced via mitosis, and will enter the first stage of meosis (as primary ooctyes at prophase I) until puberty. At puberty, 1 each is released on a monthly basis and this egg completes the first meotic division, giving rise to a large secondary ooctye and a polar body (which has half the DNA but to cytoplasm). Meosis is completed only after the egg is fertilized by the male sperm.
The second meotic division in the egg gives the secondary ooctye and another smaller polar body. The sperm CANNOT fuse with the secondary ooctye. It must wait until the secondary ooctye has matured into an ovum before fusion can occur. |
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Chapter 11. How many total cells can results from the complete development of 1 spermatogonium? What about one oogonium?
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1 spermatogonium = 4 cells.
1 oogonium = 3 cells (only three cells because the first polar body does not divide). |
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Chapter 11. The primary ooctye is usually surrounded by a layer of cells called the ______, and the entire structure is called a ______.
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Granulosa cells. Follicle.
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Chapter 11. An immature primary ooctye is surrounded by a layer of granulosa cells, forming a _____. What do the granulosa cells serve to do?
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Primordial follicle. The granulosa cells help in the maturation of the primary oocyte.
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Chapter 11. As the primordial follicle matures, the granulosa cells do what? and what does the ooctye do to increase its protection?
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Granulosa cells covering the primary ooctye proliferate from one layer of cells to several layers. The oocyte itself also forms a protective layer of monosaccharides called the zona pellucida.
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Chapter 11. There are several follciles in the ovary, what are they all surrounded by within?
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Thecal cells, which are analogous to the testicular interstitial cells in the male.
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Chapter 11. Of several maturing follicles, only one progresses to the point of ovulating each month. What happens to the others? The mature follicle is called the ______. What happens to this structure during ovulation?
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The other follicles that did not reach the point of ovulation each month degenerate. This selected follicle becomes the Graafian follicle.
During ovulation, the Graafian follicle bursts and releases the secondary oocyte with its zona pellucida into the fallopian tube. The remaining follicular cells become the corpus luteum after the Graafian follicle bursts. |
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Chapter 11. Estrogen is made and secreted by the _____ in the first half of the menstrual cycle. What about the second half?
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In the first half of the menstrual cycle, estrogen is secreted by the granulosa cells. In the second half, estrogen is secreted by the corpus luteum along with progesterone.
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Chapter 11. Estrogen is important for what three things for a woman?
What two things is progesterone important for in a woman? |
-Estrogen:
1) Pregnancy. 2) Development of secondary sexual characteristics. 3) Menstrual cycle. -Progesterone: 1) Hormonal regulation of the menstrual cycle 2) Pregnancy. |
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Chapter 11. What are the three phases of the ovarian cycle within the menstrual cycle?
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1) Follicular phase: the primary follicle matures and secretes estrogen. Follicular maturation is under the control of FSH, which is secreted from the anterior pituitary.
2) Ovulatory phase: the secondary oocyte is released from the ovary. This is caused by a surge in LH. 3) The luteal phase: characterized by the full formation of the corpus luteum, which secretes both estrogen and progesterone. |
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Chapter 11. Where are the hormones that direct the uterine cycle secreted from?
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The hormones secreted from the ovarian cycle directs events in the uterine cycle.
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Chapter 11. What are the three phases of the uterine cycle?
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1) Menstruation-triggered by the degeneration of the corpus luteum and subsequent drop in estrogen and progesterone levels, which results in the sloughing off of the endometrial lining.
2) Proliferative phase: estrogen produced by the follicle induces proliferation of a new endometrium. 3) Secretory phase: estrogen and progesterone produced by the corpus luteum further increase development of the endometrium, which includes the secretion of lipids, glycogen, and other material. |
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Chapter 11. Where is the secondary oocyte during the secretory phase?
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The secondary oocyte is in the fallopian tubes on its way to the uterus during the secretory phase. If it fails to implant, menstruation begins.
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Chapter 11. What are the hormones involved in the menstrual cycle and what are their relative levels throughout the 28 day cycle?
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Refer to page 287 in the Biological Sciences review.
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Chapter 11. What hormones does the corpus luteum require to avoid regression?
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LH.
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Chapter 11. How does the corpus luteum regress? How do the relative amounts of certain hormones cause this to occur?
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The regression of the corpus luteum is caused by a sharp drop in LH, which is caused by a relative increase in the amount of estrogen and progesterone.
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Chapter 11. If implantation occurs, what occurs to stops the corpus luteum from regressing?
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The HCG hormone (a LH like hormone) is secreted and keeps the corpus luteum protected from degeneration.
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Chapter 11. How is ovulation prevented during pregnancy?
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Pregnancy prevents ovulation by preventing LH surges, which is achieved by maintaining levels of high levels estrogen and progesterone.
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Chapter 11. The _____ is the portion of the placenta derived from the zygote.
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Chorion.
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Chapter 11. What is the only hormone that stays in high levels after menopause?
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LH, which exists in high levels after menopause because there is no more estrogen and progesterone to inhibit its production.
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Chapter 11. Sperm are activated once they reach the ______. What happens when they become activated?
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Sperm are activated when they reach the entrance of the uterus. When they are activated, dilution of inhibitory substances occur.
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Chapter 11. How are inter-species mating prevented at the molecular level?
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Different species have different bindin in the male sperm, which is a species specific protein that binds to receptors on the zona pellucida of the egg.
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Chapter 11. What are the two types of blocks to prevent polyspermy?
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1) Fast block, which involves the depolarization of the egg's plasma membrane. This prevents other sperm from fusing with the plasma membrane.
2) Slow block, AKA the cortical reaction. This involves the swelling of the space between the zona pellucida and the plasma membrane and the hardening of the zona pellucida. |
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Chapter 11. The first step of embryogenesis is ______. The cells in the developing morula skip what two phases in the cell cycle?
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Cleavage, in which the zygote divides many times to form a morula (a ball of cells).
The cells in the developing morula skip the G1 and G2 phases of the cell cycle. |
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Chapter 11. The blastocyst contain the ______ on the outer layer, which will turn into the ______ of the developing embryo, and the _____, which becomes the _______.
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Trophoblast-becomes the chorion of the embryo.
Inner cell mass, which becomes the embryo. |
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Chapter 11. Before the placenta develops, hows does the embryo receive nutrients from the mother?
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The embryo is implanted in the uterus before the placenta develops, during which the embryo can extract valuable nutrients (glycogen, lipids, etc.) from the endometrium. This is why HCG is important to maintain the endometrium.
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Chapter 11. During the last months of pregnancy, the corpus luteum is no longer needed because _____.
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The placenta itself secretes enough progesterone and estrogen to maintain the endometrium.
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Chapter 11. The development of the placenta involves the _____.
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Formation of the placental villi, in which chorionic projections extend into the endometrium, into which fetal capillaries will grow. Surrounding the villi are sinuses filled with maternal blood.
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Chapter 11. Other than the embryo itself, what are three other structures which the inner cell mass will form and what are their functions?
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1) Amnion-fluid filled cavity which contains the developing embryo.
2) Yolk sac: stores the yolk in reptiles and bird as a form of nourishment. For mammals, the yolk sac is the initial site of RBC synthesis. 3) Allantois-forms the blood vessels of the umbilical cord. |
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Chapter 11. Gastrulation in primitive organisms involves the invagination of the cells of the ________. Three layers results, the ectoderm, mesoderm, and endoderm. The mesoderm derives from what layer? The opening that forms from the invagination is called the ____, and will form the _____ of the organism.
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Gastrulation involves the invagination of cells of the blastula. The opening that results from the invagination is called the blastopore and forms the anus of the organism.
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Chapter 11. What structures form from the ectoderm (there are 5)?
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1) The entire nervous system.
2) Pituitary gland and the adrenal medulla. 3) Cornea and lens. 4) Epidermis of skin and derivatives. 5) Nasal, oral, and anal epithelium. |
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Chapter 11. What structures form from the mesoderm (there are 4)?
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1) All muscle, bone, and connective tissue.
2) Entire CV and lymphatic system including blood. 3) Urogenital organs (kidneys, ureters, gonads, reproductive ducts). 4) Dermis of skin. |
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Chapter 11. What structures form from the endoderm (there are five).
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1) Gi tract epithelium (except mouth and anus).
2) Gi glands (liver, pancreas, etc.) 3) Respiratory epithelium. 4) Epithelial lining of urogenital organs and ducts. 5) Urinary bladder. |
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Chapter 11. Epithelial cells from outside the body are formed from what germ layer? What about epithelial cells from inside the body?
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Epithelial cells from the inside the body are formed from the endoderm. Epithelial cells from outside the body are formed from the ectoderm.
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Chapter 11. What happens during neurulation? The formation of the neural tube is under the directions from the _____, which derives from what germ layer?
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The nervous system forms during the neurulation process. An invagination of a part of the ectoderm forms the neural tube, which develops into the spinal cord and brain.
The development of the neural tube is under the direction of the notochord, which is derives from the meosderm. |
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Chapter 11. The notochord gives rise to the ____. When organogenesis is complete, what is the organism called? At which trimester of pregnancy is organogenesis completed?
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Vertebral column. A fetus. The first trimester.
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Chapter 11. At which trimester is the developing embryo most sensitive to toxins?
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The first trimester, which is when the organs are developing.
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Chapter 11. Does gastrulation involve cells of the trophoblast?
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No, gastrulation only involves the cells of the inner cell mass.
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Chapter 11. A radioactive dye is only detected in the placental villi. Weeks later it must also be detected in the ______:
a) Inner cell mass. 2) Trophoblast. 3) Endometrium. 4) Zygote. |
Trophoblast, because it gives rise to the chorion, which gives rise to the placenta.
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Chapter 11. Which comes first in the process of embryonic cell development: determination or differentiation?
|
Determines precedes differentiation in cell development.
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Chapter 11. Can internal as well as external factors affect a developing cell's determination?
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Yes, a cell's determination can be affected by external factors (cell-cell signals, environmental factors, etc.) or can be pre-programmed internally in the cells genome.
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Chapter 11. What is dedidifferentiation in cell physiology?
|
Dedidifferentiation refers to the process of differentiated cells returning to a totipotent state.
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Chapter 11. During pregnancy, the very high levels of what hormone repress contractions in the uterus.
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Progesterone.
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Chapter 11. Uterine excitability increases during or near pregnancy because of what three factors?
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1) Presence of oxytocin, secreted from the posterior pituitary.
2) Change in the ratio of estrogen to progesterone. 3) Uterine stretching |
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Chapter 11. Rhythmic contractions of the uterus results in a ____ feedback loop of ____ secretion.
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Rhythmic contractions of the uterus results from the positive feedback loop of oxytocin.
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Chapter 11. What are the three stages of labor?
|
1) Dilation of the cervix.
2) The actual birth involving the contractions of the uterine and skeletal muscles. 3) Expulsion of the plecenta, which separates from the wall of the uterus. |
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Chapter 11. During pregnancy, what two hormones contribute to the further development of the breasts. These two hormones inhibit what hormone that is responsible for the production of milk?
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During pregnancy, estrogen and progesterone contribute to the development of the breasts. These two hormones inhibit the release of prolactin, which is responsible for milk production.
Prolactin is released into the bloodstream after birth and estrogen and progesterone levels fall. This hormone is released (pituitary gland is stimulated by the hypothalamus) in high levels whenever the baby starts to suckle the mother's breast. |
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Chapter 11. Prolactin is responsible for milk production. What hormone is responsible for milk release?
|
Oxytocin is responsible for milk release. This hormone is also released when suckling begins.
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