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82 Cards in this Set
- Front
- Back
Light microscopes: |
uselight and glass lenses to magnify an image |
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Ascanning electron microscope is used to study _____, whereas a transmissionelectron microscope is used to study__. |
cellsurfaces . . . internal cell structures |
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Why is the surface area to volume ratio in a cell important? |
The important point is that the surface area to the volume ratio gets smaller as the cell gets larger.
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Plasma Membrane |
the outer membrane that acts like the boundary between the inside and outside. |
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Thecomponents of cell membranes are___ |
Different types of proteins and cholesterol embedded in a double layerof phospholipids |
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Aphospholipid molecule is made up of__ |
A phosphorous head and two lipid tails |
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Themiddle of a phospholipid bilayer is |
A.Hydrophobic and composed of fatty acids |
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Amongthe many functions of membrane proteins some important ones are to serve as__ |
1. Transport 2. Receptors 3. Cell Recognition | Identification 4. Junctions 5. Channel 6. Enzymatic |
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Transport Protein |
Opens and closes Passage of molecule through membrane Needs energy |
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Channel Protein |
Forms a tunnel for specific molecules |
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Cell Recognition Protein |
Identifies our own cells and cells of other organisms |
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Receptor Protein |
Allow signal molecules to bind, causing a cellular response |
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Enzymaticproteins |
Directly participate in metabolic reactions |
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Junction proteins |
Form junctions between cells Cell-to-cell adhesion and communication |
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Themolecules responsible for membrane transport are |
Proteins |
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Thosecell membrane proteins that have a short chain of sugars attached to it(glycoproteins) and are like fingerprints are called ___ |
recognitionproteins |
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Whyis the cell membrane also called a “fluid mosaic”? |
The different molecules and components that move in the cell membrane. |
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What do we mean when we say that the cellmembrane (plasma membrane) is “selectively permeable”? |
Boundarybetween the outside of the cell and the inside of the cell. It is selective onwhat it lets into the cell. |
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Whichof the following energy transfers is/are possible in living systems? |
1. Light energy to chemical energy 2. Chemical energy to kinetic energy 3. Potentialenergy to kinetic energy 4. Light energy to potential energy 5. Heat to light energy |
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Whatis energy? |
capacityto do work |
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Potential energy |
Stored energy |
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Kinetic energy |
Energy from motion |
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ATP |
molecule that supplies energy for cellular work Energycurrency of cells |
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First Law of Thermodynamics |
-Conservationof energy -Energycannot be created or destroyed but it can be changed from one form to another. |
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Second law of Thermodynamics |
-Entropy -Energy cannot be changed fromone form to another without a loss of heat energy -Heat is the least usable form of energy, the most disorganized. |
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Photosynthesis |
solarenergy used to convert water and carbon dioxide into carbohydrates |
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Cellularrespiration |
Carbohydratesbroken down and energy used to build ATP |
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Flow of energy |
In ecosystems, energy flows in one direction. Some is usedand the rest is lost as heat. |
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Metabolic pathway |
seriesof linked reactions |
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What are enzymes |
Proteinmolecules that function as catalysts to speed up reactions |
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Active cite of Enzyme |
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Substrate |
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Feedbackinhibition |
-When a product is in abundance, it competes with substrate for activesite -An end product of a pathway can inhibit the first enzyme in the pathway |
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Enzymeinhibition |
Occurs when an active enzyme is prevented from combining with itssubstrate Examples: Cyanide is a poison because it binds to and inhibits cytochrome coxidase.§Penicillin interferes with a bacterial enzyme that kills the bacteria. |
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diffussion |
from high to low Passive Transport (No energy req) |
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HyPERtonic |
The solution with the higher concentration of solutes |
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HyPOtonic |
The solution with the lower concentration of solutes |
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Isotonicsolution |
•Cellneither gains nor loses water•Concentrationof water same on both sides of the membrane •0.9%saline isotonic to red blood cells |
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Hemolysis |
the rupture or destruction of red blood cells.
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Crenation |
A process resulting from osmosis in which red blood cells, in a hypertonic solution, undergo shrinkage and acquire a notched or scalloped surface.
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Solvent |
Liquid portion of a solution |
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Solute |
Substance dissolved in a Solvent forming a solution |
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Solution |
contains both solvent AND solute |
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Osmosis |
is the diffusion of water across a semipermeable membrane, from an area of higher concentration to an area of lower concentration. |
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Osmosis occurs through channel proteins called |
aquaporins |
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Does Osmosis req energy |
no |
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In osmosis do water molecules move up or down in their concentration gradient? |
Down |
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Is Osmosis a passive or active transport Mechanism? |
passive |
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Exocytosis |
– movement out of cell |
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Endocytosis |
- movement in |
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Active transport |
Cells expend energy to move molecules against a concentration gradient. |
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Bulk Transport |
Macromolecules are often too large to be moved by transport proteins |
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Phagocytosis |
solidparticle |
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Pinocytosis |
Liquid or small particles |
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Receptor-mediatedendocytosis |
Receptors for particular substances found in coated pit – selective and more efficient |
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Granum |
A stack of thylakoid discs |
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Pigments |
solar energy is absorbed by chlorophyll and other photosynthetic______ |
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which structure houses the photosynthetic pigments? |
thylakoid |
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Which chemicals are output in photosynthesis? |
oxygen and glucose |
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Which chemicals are input in photosynthesis? |
water and carbon dioxide |
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what types of molecules are coenzymes? |
non-proteins |
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Theunit used by biologists to measure energy is the |
calorie |
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Whichone of the following processes is endergonic? |
the synthesis of glucose from carbondioxide and water using energy from the sun |
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Kineticenergy differs from chemical energy in that___ |
kinetic energy is the energy of a movingobject, whereas chemical energy is the potential energy of molecules. |
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Abull must eat at least 100 pounds of grain to gain less than 10 pounds ofmuscle tissue. This illustrates |
the second law of thermodynamics |
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Whatis the basic difference between exergonic and endergonic reactions? |
Exergonic | Release energy endergonic | absorb energy |
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Mostenzymes end in ___ by international agreement |
ase |
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The fluid mosaic model describes the plasma membrane as consisting of |
individual proteins and phospholipids that can drift in a phospholipid bilayer |
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Anenergy barrier is |
What must be overcome to start the reaction |
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Enzymesfunction by____ |
-enzymesspeed up the cell’schemical reactions by lowering energy barriers -enzymes work by lowering theactivation energy, which means lowering the amount of energy needed to get areaction going |
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Whenan enzyme catalyzes a reaction |
Itlowers the activation energy of the reaction |
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Mostof a cell's enzymes are |
proteins. |
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Mostenzymes end in ___ by international agreement |
•ase |
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Whichone of the following is false? |
Enzymes emerge unchanged from thereactions they catalyze. |
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Achild is brought to the hospital with a fever of 107°F. Doctors immediatelyorder an ice bath to lower the child's temperature. Which explanation offersthe most logical reason for this action? |
Elevated body temperatures may denature enzymes. This would interferewith the cell's abilities to catalyze various reactions. |
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Whichof the following can affect the rate of an enzyme-catalyzed reaction? |
-temperature -pH -competitive inhibitors -noncompetitive inhibitors |
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Glycolysis |
•resultsin the production of pyruvate and occurs in the cytoplasm. |
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Theend product(s) of glycolysis is (are) |
•pyruvate. |
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Rough ER |
synthesize polypeptides
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Smooth ER, |
synthesizes lipids, such as phospholipids and steroids |
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Golgi Apparatus |
SHIPPING First, it receives transport vesicles sent to it by rough and smooth ER. The molecules within the vesicles are modified as they move between saccules. Finally, the Golgi apparatus sorts the modified molecules and packages them into new transport vesicles according to their particular destinations |
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Lysosomes |
produced by the Golgi |