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204 Cards in this Set
- Front
- Back
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What Physiology is primarily concerned?
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Physiology is primarily concerned with the molecular level up through populations
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What are physiologists concerned with?
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Physiologists are interested in everything from the molecular level to how physiological adaptations affect an organism’s ability to adapt to and survive in particular environments
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Are lymphatics a system?
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The question sometimes arises about whether the lymphatics are a system. They are an anatomical system, but physiologically, the lymphatics function as part of three systems:
• Circulatory (returning excess fluid and escaped proteins from interstitial space to the plasma), • Digestive (transporting fats from the intestine to the circulation), • Immune (lymph nodes contain clusters of immune cells). Thus, in a physiology course they are often not considered a system. |
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What are the 3 part system of the lymphatic system?
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• Circulatory (returning excess fluid and escaped proteins from interstitial space to the plasma),
• Digestive (transporting fats from the intestine to the circulation), • Immune (lymph nodes contain clusters of immune cells). Thus, in a physiology course they are often not considered a system. |
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Physiology is an integrative science. Organ systems often operate as integrated units. Give examples of integration?
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* An example of integration is the regulation of calcium concentration in the body.
• The endocrine system acts on bones, kidneys, and intestine to ensure that plasma calcium concentrations remain within a certain range. |
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What are the ten organ systems?
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1. Circulatory (cardiovascular) – made up of the heart, blood and vessels.
• Function: is to transport materials between all cells of the body. 2. Digestive (gastrointestinal or GI) – consists of the GI tract. • Function: to process food for energy and nutrient uptake. 3. Endocrine – made up of various glands and cells. • coordinates body functions through the synthesis and release of regulatory molecules. 4. Immune – made up of lymphatic tissue with some parts of the integumentary and circulatory systems. • it protects against invaders. 5. Integumentary – consists of the skin and its derivatives. • protection from the external environment. 6. Musculoskeletal – made up of skeleton and bones. • primary function is support and movement. 7. Nervous – consists of the brain, spinal cord and nerves. • coordinates function through electrical signals and release of regulatory molecules. 8. Reproductive – made of the gonads and accessory structures. • functions to perpetuate the species. 9. Respiratory – made up primarily of the lungs. • O2 and CO2 exchanges between the internal and external environments. 10. Urinary (renal) – consisting of the kidneys and bladder. • It maintains the internal environment by regulating water and solutes and by removing wastes. |
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What is the circulatory organ system and function?
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1. Circulatory (cardiovascular) – made up of the heart, blood and vessels.
• Function: is to transport materials between all cells of the body. |
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What is the digestive organ system and function?
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2. Digestive (gastrointestinal or GI) – consists of the GI tract.
• Function: to process food for energy and nutrient uptake. |
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What is the endocrine system and function?
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3. Endocrine – made up of various glands and cells.
• coordinates body functions through the synthesis and release of regulatory molecules. |
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What is the immune system and its function?
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4. Immune – made up of lymphatic tissue with some parts of the integumentary and circulatory systems.
• it protects against invaders. |
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What is the integumentary system and function?
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5. Integumentary – consists of the skin and its derivatives.
• protection from the external environment. |
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What is the musculoskeletal system and function?
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6. Musculoskeletal – made up of skeleton and bones.
• primary function is support and movement. |
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What is the nervous system and its function?
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7. Nervous – consists of the brain, spinal cord and nerves.
• coordinates function through electrical signals and release of regulatory molecules. |
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What is the reproductive system and function?
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8. Reproductive – made of the gonads and accessory structures.
• functions to perpetuate the species. |
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What is the respiratory system and function?
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9. Respiratory – made up primarily of the lungs.
• O2 and CO2 exchanges between the internal and external environments. |
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What is the urinary system and function?
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10. Urinary (renal) – consisting of the kidneys and bladder.
• It maintains the internal environment by regulating water and solutes and by removing wastes. |
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Physiology cuts across many levels of organization. While we understand how most of the body works at the system level, we are still learning about the human body at the molecular and cellular levels.
One difficulty in acquiring this knowledge is that there is such an interdependence between various submolecular, molecular, cellular, tissue, organ and system phenomena that it is difficult to study. ~Adding to this complexity is the number of emergent properties within the human body. What is an emergent property? |
• An emergent property is some property of a system that is greater than the simple sum of the individual parts. These include such things as emotion, intelligence and memory
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Remember that the science of physiology is based on normative values that reflect averages of the population, not an individual. What is a ecological fallacy and give an example?
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it is wrong to say that someone who smoked a cigarette will lose 3 minutes off their life because of it. Yes, it is true that on average, people who smoke will have more health problems and a shorter life span, but you cannot attribute the qualities of the group to one individual. This is known as an ecological fallacy.
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What are the two opposing views of life that attempt to explain natural phenomena
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TELEOLOGICAL VS. MECHANISTIC APPROACH
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What is the mechanist view of life?
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The mechanist view of life, the view often taken by physiologists, holds that all phenomena are describable in terms of physical and chemical laws. It essentially says that human beings are machines and can be broken into sub units for study. It is considered to be the “how” of the system.
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What is the teleology view of life?
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Teleology holds that some additional force is required to explain the function of living organisms.
It is often called the “why” of the system. |
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Which idea teleology or mechanists view is most popular and why?
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For the past 100 years or so the mechanistic view has predominated because of the abundance of experimental evidence that has supported it.
This idea makes the study of physiology extremely broad ranging from the molecular genetic level to the interactions of organisms with their environment. |
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What is one problem with teleology?
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One problem that comes up when studying physiology is teleology. This is when we explain physiological events in terms of a purpose. An example would what does glucose “want” to do once it gets inside the blood stream? Be careful of this (but I will do it sometimes too).
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Define homeostasis?
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Homeostasis is often defined as the maintenance of a constant internal environment and is the underlying theme of physiology.
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Who were the two people who found and coined the work homeostasis?
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Physiologist Claude Bernard is credited for coming up with the idea of homeostasis, however, Walter Canon actually coined the term homeostasis which he meant same within oneself.
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How does homeostasis maintain stability?
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In homeostasis, the body maintains stability of internal environment by correcting any changes through negative feedback.
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What are 3 key main points of homeostasis?
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1) the parameters are maintained within narrow limits,
2) there exists a dynamic steady state and 3) homeostatic control mechanisms detect changes and initiate compensatory responses to restore level of the controlled variable. |
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Homeostasis is controlled by which two systems?
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Homeostasis is controlled by two systems: intrinsic control systems and extrinsic control systems.
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What is an intrinsic control system and give an example?
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• An intrinsic control system is also known as local control or autoregulation. In this type of regulation, the control comes from within the system itself.
o There is no control from an outside source. o An example of this is when an arteriole will control its own diameter based on pressure and flow within the system itself. o It is an intrinsic control because this works even if the arteriole is removed from the body and placed in a beaker. |
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What is an extrinsic control system?
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• An extrinsic control system is one that comes from outside the system being controlled.
There are two types of extrinsic control: humoral and neural. |
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What are two types of extrinsic control?
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There are two types of extrinsic control: humoral and neural.
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What is humoral control?
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o Humoral control refers to substances carried in the blood or fluids. This refers primarily to the endocrine system.
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What is neural control?
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o Neural control refers to the nervous system. The autonomic nervous system is primarily involved here. Arteriolar diameter is also controlled extrinsically.
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Chemicals from outside the system can cause what to the body and results in ?
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Chemicals from outside the system can cause constriction (epinephrine) or dilation (nitric oxide). In addition, the sympathetic nervous system also changes arteriolar diameter based on its activity.
~If we fail to maintain homeostasis, disruption of body function will result. In fact, failure to maintain homeostasis leads to pathophysiological conditions—disease states. |
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Diseases generally arise in what two categories?
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• Problem arises from internal failure of normal physiological process (autoimmune diseases)
• Problem arises from some outside source (pathogenic bacteria, virus, etc.) |
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Give an example of integrative physiology?
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Diabetes mellitus as a good example of integrative physiology.
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What are the four basic themes in physiology?
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There are four basic themes, which run through physiology.
1. Homeostasis and control systems 2. Biological energy 3. Structure/function relationships 4. Communication |
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What theme does Homeostasis and control systems provide?
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1. Homeostasis and control systems – body systems work together to maintain homeostasis (constant internal environment).
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What theme does biological energy provide?
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2. Biological energy – living processes require continuous input of energy.
• Energy is used for synthesis and breakdown of molecules, to transport molecules across membranes or against gradients and for movement. |
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What theme does structural /function relationships provide?
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3. Structure/function relationships – the integration of structure and function is another physiological theme.
• Molecular interaction - the ability of molecules to react is vital to this integration. The mechanical properties of various systems also influence their function. • Compartmentation is the presence of separate body compartments (separated by membranes) which allows areas to specialize their functions. This allows more specific function. |
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What theme does communication provide?
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4. Communication – cell-to-cell communication and coordination is vital to integration of systems.
• A variety of methods exists that allow cells to communicate mostly related to chemical and electrical signals. Various sensors relay information about specific internal and external conditions. This allows information to flow especially across cell membranes. • Communication between internal and external cellular environments requires information transfer across the cell membrane. o Cell membranes are selectively permeable, allowing some substances to pass while prohibiting others. However, there may be proteins present that allow molecules or their signals access to the interior of the cell. o In addition, substances move throughout and within body compartments by the principle of mass flow. There must be a driving force such as a pressure or concentration gradient. Mass flow is usually discussed in relation to time. o It can be described by the equation: mass flow (amount/minute) = concentration (amount/volume) x volume flow (volume/minute). |
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1. At rest, the typical left ventricle of the heart pumps 5.0 liters of blood per minute. Blood flow to the kidneys is approximately 1,200 ml per minute at rest. Assuming a constant proportionality, what will be the blood flow to the kidneys if the heart pumps 6.5 liters per minute?
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This problem is easiest to work if the units are all the same, so first you need to convert ml to liters. You could do it the other way, but liters are easier to work with in this instance. In order to that, we take:
1,200 ml x (1 liter / 1000 ml) = 1.2 liters. Then, 1.2 / 5 = X / 6.5, so X = 1.2 x 6.5 / 5 = 1.56 L/min |
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An electrocardiogram is recorded on mm grid paper (paper where the grids are 1 mm apart) moving at a speed of 25 mm per second. If the distance between cycles as recorded is 21.4 mm, what is the subject’s heart rate in beats per minute?
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(25 mm / sec) x (1 beat / 21.4 mm) x (60 sec / 1 min) = 70.0 beats/min
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A differential white blood cell count was determined to have the following values for each type of white blood cell. Determine the percentages of each type of white blood cell present in the samples. A total of 143 cells were counted.
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Perhaps the easiest way to approach this problem is to make additional columns like the ones you see below added to the original data. You also need to add up the total number (n). In this case, the total number of cells counted is 143. Then you need to divide each number of individual counts by the total to get the individual percentage. The expected percentage is provided as a guide. You can also check to make sure the total percent adds up to something close to 100. It does in this case.
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What is the formula for standard deviation?
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What is the mean?
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The first to so here is to calculate the mean. Remember that the mean is calculated as the summation of x / n (which in English means add up all of the numbers and divide by the number of cases you have.
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You want 500 ml of a 1M glucose solution. How would you prepare that solution in the most efficient way?
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To prepare the solution in the most efficient way means to have no waste. This problem is easiest if you just use definitions. To prepare a 1M glucose solution, you would put 1 mole of glucose in 1 liter of solution (by definition). Thus, it follows that a 500 ml solution (half a liter as a liter is 1000 ml) would require half a mole of glucose. In order to know how much a half mole of glucose is, we need to calculate the formula weight for glucose first. The formula for glucose is C6H12O6. Each element has a specific molecular weight. Carbon (C) has a molecular weight of 12. Since there are 6 carbons, they add up to 72 (number x molecular weight or 6 x 12 = 72). There are 12 hydrogens (H) with each having a molecular weight of 1. Thus, they account for 12 (12 x 1 = 12). Lastly, oxygen (O) has a molecular weight of 16. This would account for 96 (6 x 16 = 96). Adding them all up gives us a total of 180. Thus, since one mole of glucose will be 180 grams it follows that one half mole of glucose will be 90 grams. So we need to add 90 grams of glucose to 500 ml of water to prepare the solution in the most efficient way.
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You want 500 ml of a 1M glucose solution. How would you prepare that solution in the most efficient way? Use dimentional analysis
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How much NaCl do you need to make 100 ml of a 1.5% solution? How much glucose do you need to make 100 ml of a 1.5% solution?
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Since percent solutions only depend on the percentage amount per 100 ml, you would need 1.5 grams. This is true since 1 gram of water = 1 ml of water in the metric system. Thus, 100 ml is also 100 grams. When looking at it this way, it should be obvious that 1.5% of 100 grams is 1.5 grams. Thus, to make a 1.5% solution you need to 1.5 grams. Also note that percent solutions are independent of the substance involved, so they tell us little about the actual nature of the solution. The answer would be the same for any substance that would dissolve in water. Because of this, percent solutions are not often used in physiology.
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Given a glucose solution where 360 grams of glucose was added to 1 liter of solution, calculate the concentration in mg/dL.
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Given: 360 grams of glucose placed into 1 liter of solution.
To go from g / L to mg / dL we need to change the g to mg and L to dL. (360 g / 1 L) x (1000 mg / 1 g) x (1 L / 10 dL) = 36,000 mg / dL |
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Given a glucose solution where 360 grams of glucose was added to 1 liter of solution, calculate the concentration in mg/dL to mmol/L.
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Given: 360 grams of glucose placed into 1 liter of solution
36,000 mg / dL To go from mg / dL to mmol / L we can use the formula (mmol / L = mg / dL x 10 / molecular weight). Remember that the molecular weight is calculated by the sum of the individual molecular weights. For glucose (C6H12O6) it is 180. 36,000 mg / dL x (10 / 180) = 2,000 mmol / L . |
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Given a glucose solution where 360 grams of glucose was added to 1 liter of solution, calculate the concentration in grams to moles.
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Given: 360 grams of glucose placed into 1 liter of solution.
Alternatively, you can use the common chemistry formula to go from grams to moles. 360 g / 1 liter x 1 mole / 180 g = 2 moles / liter or 2 M This value then needs to be converted to mmol/L. This is easily done by dimensional analysis. 2 moles / liter x 1000 mmol / 1 mole = 2000 mmol / L |
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Given a glucose solution where 360 grams of glucose was added to 1 liter of solution, calculate the concentration in mosmol/L.
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Given: 360 grams of glucose placed into 1 liter of solution.
For mosm / L we use the formula (mosm / L = mmol / L x number of dissociable particles). The number of dissociable particles is found by looking at the added substance and seeing whether or not it breaks into smaller pieces (dissociates). All ionic bonds will dissociate, but covalent will not. This is important since it is the actual number of particles in a solution that determines the osmotic force, not the size or charge of the particle. Glucose remains intact when placed in water, so it is considered to be 1 dissociable particle. 2,000 mmol / L x 1 = 2,000 mosm / L |
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Given a saltwater solution where 116 grams of NaCl was added to 1 liter of solution, calculate the concentration in mg/dL, mmol/L, meq/L, and mosmol/L.
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Given: 116 grams of NaCl placed into 1 liter of solution.
We first need to calculate the concentration in mg/dL. This problem is easiest to approach if we take what we started with and cancel the corresponding units through dimensional analysis to end up with what we need. To go from g / L to mg / dL we need to change the g to mg and L to dL. (116 g / 1 L) x (1000 mg / 1 g) x (1 L / 10 dL) = 11,600 mg / dL To go from mg / dL to mmol / L we can use the formula (mmol / L = mg / dL x 10 / molecular weight). Remember that the molecular weight is calculated by the sum of the individual molecular weights. For NaCl it is 58. 11,600 mg / dL x (10 / 58) = 2,000 mmol / L |
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Given a saltwater solution where 116 grams of NaCl was added to 1 liter of solution, calculate the concentration from grams to moles.
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Alternatively, you can use the common chemistry formula to go from grams to moles.
116 g / 1 liter x 1 mole / 58 g = 2 moles / liter or 2 M This value then needs to be converted to mmol/L. This is easily done by dimensional analysis. 2 moles / liter x 1000 mmol / 1 mole = 2000 mmol / L Notice you get the same answer by either method. |
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Given a saltwater solution where 116 grams of NaCl was added to 1 liter of solution, calculate the concentration in mosmol/L.
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For mosm / L we use the formula (mosm / L = mmol / L x number of dissociable particles). The number of dissociable particles is found by looking at the added substance and seeing whether or not it breaks into smaller pieces (dissociates). All ionic bonds will dissociate, but covalent will not. This is important since it is the actual number of particles in a solution that determines the osmotic force, not the size or charge of the particle. NaCl dissociates into Na and Cl, so it is considered to be 2 dissociable particles.
2,000 mmol / L x 2 = 4,000 mosm / L |
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What is the range?
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The range is calculated as the difference between the highest and lowest scores. Mathematically, it is:
Range = highest Xn - lowest Xn |
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What is the common standard computations using ratios in the lab?
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This is simply a mathematical statement of the equality of 2 ratios.
A/B = C/D (in this equation, A/B & C/D are ratios) |
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What is percentage and its formula?
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This is simply a part of a whole expressed in hundredths.
A/B x 100 = % or measured/expected x 100 = % |
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What is the standard molecule to mole formula given a molecular weight of 111, calculate the mOsm of a solution of CaCl2 if 22.2 grams of the substance were added to 1 liter of water.
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1. 22.2g/dL x 10dL x 1mol/111g=0.2mol
2. 0.2mol x 1000mmol = 200mmol 3. 200mmol x 3mosm = 600mosm |
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What are non electrolytes?
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Non electrolytes are organic molecules that are uncharged. They are made up of covalent bonds that include glucose and lipids.
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What are electrolytes?
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Electrolytes are inorganic salts made up of ions. Therefore, they are charged and by definition, can conduct electricity. Because they are ionic, each molecule produces two or more particles (ions) through dissociation. Since they break up into multiple particles, they are important in determining the osmolality of body solutions because each particle exerts osmotic action. Thus, a solution of sodium chloride (NaCl) will dissociate into two particles (Na+ and Cl-) and will exert twice as much osmotic force as a similar concentrated molecule that does not dissociate. Likewise, CaCl2 will dissociate into three particles. Because of this fact, concentrations of electrolytes are often given in the number of charges per liter.
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What is a solvent?
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A solvent is a liquid or gas in which some other material (solute = solid, liquid, or gas) has been dissolved.
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What is a solute?
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A solute is the material (solid, liquid, or gas) that is dissolved in the solvent (liquid or gas).
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What is a solution?
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A solution is a mixture of a solvent and solute (e.g. NaCl in water).
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What are some of the conditions on being a solution?
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In order to be a solution, it must have the following properties. The solute does not settle out. It cannot be separated from the solvent by filtration. It can, however, be retrieved by boiling off the solvent through distillation. The components of the solution cannot be distinguished when they are mixed together. The liquid portion of blood (plasma) forms a solution in which oxygen, carbon dioxide, and ions (such as NaCl) are transported.
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What is a suspending medium?
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A suspending medium is a liquid where the material can mix, but will eventually settle out.
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Give an example of an suspended medium?
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A colloid is the material placed in a suspending medium, which eventually settles out.
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What are some ways concentrations can be expressed as measurements?
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It can be expressed as: milligrams per deciliter (mg/dL - also known as milligrams per 100 milliters and milligrams percent), milliequivalents per liter (meq/L), millimoles per liter (mmol/L) or milliosmoles per liter (mosmol/L).
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What is milligrams per deciliter?
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(mg/dL - also known as milligrams per 100 milliters and milligrams percent). This is simply a measure of the concentration of a substance with a liquid. It is a measure of the weight of a substance within a given volume. This is a very common method to report concentration.
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What is Millimoles per liter (mmol/L)?
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The atomic weight is an assigned number to an element, which allows comparison of relative weights between elements. It is a unitless value purely based on their relative ratios. The molecular weight of a molecule (MW), is the sum total of all the weights of its constituents. For example since oxygen has a MW of 16 and hydrogen of 1, H2O has a MW of 18 [(2 x 1) +16]. One mole (mol) of any substance is defined as the MW of that substance in grams. Thus, one millimole (mmol) is equal to one-thousandth of a mole or the MW in milligrams. Since the MW of sodium is 23, 23 mg of sodium is equal to 1 mmol. If this solution was put into a liter of water, it would be 1 mmol/L of sodium. To convert from milligrams per deciliter (mg/dL) to mmol/L, use the following formula:
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To convert from milligrams per deciliter (mg/dL) to mmol/L, use the what formula?
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mmol/L = (mg/dL) x (10 dL/1 L) x (1 mole/MW) x (1 g/1000 mg) x (1000 mmol/1 mole)
or more simply put (this is a shortcut for converting mg/dL to mmol/L) mmol/L = mg/dL x 10/MW. |
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What is Milliosmoles per liter (mosmol/L)?
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The osmotic pressure of a solution is proportional to the number of particles per unit volume of solvent, not to the type, valence or weight of particles. The unit of measurement of osmotic pressure is the osmole (osm or osmole). One osmole is defined as one-gram molecular weight (1 mmol) of any non dissociable substance. In relatively dilute fluids in the body, this is measured in terms of milliosmoles per kilogram of water. To convert, use this formula.
mosmol/kg = n x mmol/L (where n is the number of dissociable particles) |
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When does ionization happen?
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Ionization happens when molecules of acids, bases, or salts are placed in water and they break apart into positively charged cations and negatively charged anions. Since glucose is not as acid, base or salt, it dissolves but it does not ionize when placed in water.
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What is an acid?
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An acid is defined as any substance that dissociates into one or more H+ and one or more negative anions. Alternatively, it is any substance, which is a proton donor. As an example:
HCl------->H+ + Cl- |
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What is a base?
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A base is any substance, which dissociates into one or more hydroxyl ions (OH-) and one or more positive ions. Alternatively, it is known as any substance that is a proton acceptor. As an example:
NaOH------> Na+ + OH- |
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What is a salt?
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A salt is any substance which dissociates into cations and anions neither of which is H+ or OH-. Acids and bases react with each other to form water and a salt. As an example:
HCl + NaOH-------> NaCl + H2O |
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What is the pH scale?
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The pH scale is a way of expressing the number of hydrogen ions (H+) or hydroxide ions (OH-) in a solution. The scale is logarithmic in nature such that a shift of one pH unit changes the H+ or OH- ion concentration ten times.
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Give an example of the change in PH and its relative increase or decrease in H+ ions?
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If the pH changes from a pH 7-->pH 6 = 10x increase in H+; 10x decrease in OH-
If the pH changes from a pH 7-->pH 5 = 100x increase in H+; 100x decrease in OH- |
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What is the ph of arterial blood?
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The pH of arterial blood is 7.40. If the blood pH shifts to 6.90 or 7.80 the person will die. Shifts of less than one pH unit are very significant because of the effect they have on enzyme function and the fact that it is a log scale.
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How many grams in a kilogram
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1000 grams in 1 kilogram
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Hom many grams in a milligram
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o.oo1 gram for 1 milligram
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How many grams in a picogram?
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10 to the negative 12 grams per 1 pico gram.
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How many grams in a microgram?
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10 to the negative 6 gram per 1 microgram.
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What is the formula for mOsm?
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mOsm = mM (mMol) x the number of dissociable particles
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What are the disassociated particles for the following?
A) urea = 1 B) glucose C) NaCl D) KCl E) CaCl2 |
A) urea = 1
B) glucose = 1 C) NaCl = 2 D) KCl = 2 E) CaCl2 = 3 |
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As an example, say you are given 100 mmol of NaCl. Since the number of dissociable particles is 2 for NaCl- what sis the mOsm?
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then we have 200 mOsm of NaCl because 100 mmol NaCl x 2 is 200 mOsm NaCl.
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In addiiton, since the osmocicity and tonicity are due solely to the number of dissolved particles in a solution, these can be added together. For instance we put 200 mmol of glucose and 100 mmol of NaCl into a solution- whats is the total # of mOsm?
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The mOsm will be 400 for that solution since 200 mmol glucose x 1 = 200 mOsm and 100 mmol of NaCl x 2 = 200 mOsm, so the total is 400 mOsm for that solution.
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We always assume that initially the inside of the red blood cell is # of mOsm? (unless otherwise stated)
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We always assume that initially the inside of the red blood cell is 280 mOsm unless otherwise stated.
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If the concentration is the same outside as inside then it is an isosmotic solution (same as) and what is its mOdm condition inside the cell and outside?
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This would be when the solution outside the cell is 280 mOsm and the inside of the cell is 280 mOsm.
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B) If the concentration is the lower outside than inside then it is a hyposmotic solution (lower than), the what is the mOsm # inside and outside of the cell?
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This would be when the solution outside of the cell is LESS than 280 mOsm.
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C) If the concentration is the higher outside than inside then it is a hyperosmotic solution (higher than). What is the # of mOsm inside and outside of the cell?
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This would be when the solution outside the cell is MORE than 280 mOsm.
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Tonicity
In order to determine the tonicity, you need to know which molecules are permeable in the cell membrane. Which of substance is the only one permeable in a cell? |
Urea is the only substance that we are dealing with that can pass through the membrane in these problems. In additon, all solutes located inside the red blood cell are also stuck there as they cannot pass out of the cell. For completeness, here is list of permeable and nonpermeable substances you are responsible for on an exam.
A) urea = permeable B) glucose = impermeable C) NaCl = impermeable D) KCl = impermeable E) CaCl2 = impermeable |
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Why is it important that Urea is permeable and what occurs?
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Urea will diffuse into a red blood cell until it reaches equillibrium. This occurs because under most cases, the amount of urea in a red blood cell starts off as zero. Thus, half of the urea will diffuse into a red blood cell and half will stay outside the red blood cell as it reaches equilibrium. Since urea dissolves in water, it does have an osmostic action, so we have to account for the changes inside the cell and outside the cell if urea diffuses into the cell.
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In summary, What are the steps you need to determine the osmicity and tonicity of a problem you will be given in class
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1) Make sure all values are in mOsm by converting any value given in mM to mOsm by multiplying the mM (mmol) by the number of dissociable particles. When multiple substances are given, add the values together to get a single value for the outside of the cell.
2) Determine the osmicity first as this depends on the initial condition of the cell. In order to do this, you do NOT mave any particles. You just compare the mOsm outside of the cell to the inside of the cell. Remember that the inside of the cell is 280 mOsm unless otherwise noted. If they are equal it is isosmotic, if the outside has a smaller number it is hyposmotic and if the outside has a larger number it is hyperosmotic. 3) Move urea by allowing it to diffuse across the cell membrane. For most conditions, there is no urea inside a red blood cell, so it will diffuse directly across the membrane into the cell until it reaches equilibrium. This means that half of the urea will diffuse into the cell. Adjust the mOsm for the inside and outisde of the cell once urea has moved. 4) Draw an arrow from the smallest mOsm number to the largest mOsm number to indicate the movement of water. If the arrow has no direction because the values are the same, it is in an isotonic solution. Cells stay the same size in an isotonic solution as there is no net water movement. If the arrow points to the inside of the cell, water would have a net movement to the inside. This would cause the cell to gain water. By definition, this would be called a hypotonic solution. If the arrow points out of the cell, water would leave the cell. In this case the cell gets smaller. A solution that casues a cell to shrink (crenate) is called a hypertonic solution. |
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Which type of transport uses passive diffusion (uses no atp)?
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1.Simple diffusion
2.Diffusion through a membrane 3.Diffusion through a channel 4.Facilitated diffusion 5. Osmosis |
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Which of the five passive transport uses a protein?
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Diffusion through a channel & Facilitated diffusion
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Which of the five passive transport uses both a protein and an active transport?
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Facilitated diffusion
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What is the direction of movement of all passive transport?
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Down gradient
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What are the two type of active transport ?
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Primary active Transport & Secondary active transport
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Which active transport relies on energy and uses energy directly?
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Primary active transport and secondary transport both use ATP but only the primary uses energy directly.
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What is the direction of active transport?
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against a gradient
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True or False? Active transport uses a protein and a carrier.
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TRUE
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Simple diffusion has what property?
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Does not necessarily move across a membrane
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Diffusion through a membrane has what property?
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Moves in accordance to Fick’s law
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Diffusion through a channel has what property?
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Channel is a protein, but not a carrier
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Facilitated diffusion has what property?
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Displays specificity, competition and saturation
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Osmosis has what special property?
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Special case of diffusion of water
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Primary active Transport has what special property?
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Has an ATPase
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Secondary active transport has what special property?
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Relies on primary active transport
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What is matter and what is its units?
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Matter, simply defined is anything that takes up space and has mass.• The units matter that form all chemical substances are called atoms.
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What is each atom called?
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• Each type of atom is called a chemical element and is designated by a universal shorthand 1-2 letter symbol (e.g. C, H, O, etc.)
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What are atoms composed of ?
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Atoms are composed of subatomic particles called protons, neutrons, and electrons.
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What are protons, electrons, and neutrons?
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Protons have one positive charge, electrons have one negative charge, and neutrons have no charge.
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Where do protons, neutrons, and electrons reside in a cell?
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Protons and neutrons cluster into nucleus, while the electrons are found somewhere outside the nucleus.
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What is an element and what is it distinguised by?
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An element is distinguished by the unique number of protons in its nucleus.
• atomic # equals the number of protons • atomic mass equals the number of protons and neutrons. |
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What is the atomic weight refer to?
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The atomic weight refers to the mass of an atom relative to a carbon atom with a value of 12. This value often approximates the number of neutrons and protons in the nucleus.
~The actual weight for a H atom for instance is 1.67 x 10-24 g. |
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What 4 elements occur in our body cosist of?
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While there are over 90 naturally occurring elements, most of our bodies consist of CHON. These are called the major essential elements. In addition, there are minor elements and trace elements. These are things that are necessary for life, but needed in small amounts.
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What are isotopes?
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Isotopes of an element are atoms with different numbers of neutrons.
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What are some properties of electrons?
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Electrons form bonds between atoms, form ions, capture energy and form free radicals.
• Electrons are arranged into shells and orbitals that encircle the nucleus. o This has important implications for the stability of an element or molecule. Electrons can be transferred or shared between elements to form bonds between atoms. Electrons play several roles in physiology such as in communication, • capture and transfer energy, • allow movement, synthesis of molecules and proteins, and bioluminescence |
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What is a molecule and what are some of its properties?
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• A molecule is two or more atoms that share electrons.
Chemical formula indicates the number of atoms and molecular weight of a molecule. Four common bond types: • covalent bonds, • ionic bonds, • hydrogen bonds, • Van der Waals |
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What are ionic bonds?
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Ionic Bonds Form When Atoms Gain or Lose Electrons
Ionic Bond: Bond between a cation and anion Ion: Atoms that gain or lose an electron become charged and are considered to be ions (charged) |
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What are cations and anions?
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Cation: Atoms that lose an electron and therefore have a positive charge
Anion: Atoms that gain an electron and therefore have a negative charge |
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When is ionic bonding formed?
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Ionic Bond: An ionic bond is formed when oppositely charged atoms are attracted.
• The force is called electrostatic attraction and it just means that the atoms are more stable closer together. • All ionic bonds will end up with a neutral molecule, so you need to balance the individual elements in terms of charge (i.e. NaCl, CaCl2) |
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What are some properties of the following molecules?
NaCl KCl CaCl2 Glucose Urea |
Molecule Solubility in Lipids
NaCl not soluble in lipid KCl not soluble in lipid CaCl2 not soluble in lipid Glucose not soluble in lipid Urea lipid soluble |
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What are covalent bonds?
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Covalent Bonds are formed when adjacent atoms share electrons
• Covalent bond: Atoms share one or more pairs of electrons |
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What are non polar covalent bonds?
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Nonpolar covalent bond:
• Electrons are distributed evenly among atoms so that there is no net charge in molecule. o Example: CH4 (C tends to form nonpolar covalent bonds) |
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What are polar covalent bonds?
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Polar covalent bond:
• Atoms that share unequally so that the electrons are pulled closer to the nucleus thereby causing a charge distribution. • Example, H2O (O and N tend to form polar covalent bonds) |
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What are some of the properties of hydrogen bonds?
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Hydrogen Bonds are Weak Bonds between Molecules or Regions of a Molecule
• Hydrogen bond: Hydrogen forms weak bond with nearby oxygen, nitrogen, or fluorine • It can occur between neighboring molecules or give three dimensional shape to the same molecule. o For example, it accounts for surface tension in water. Water bugs are able to walk on the surface of the water because of the surface tension. o On the surface of a fluid with surface tension, spherical objects distribute their force more evenly and are supported by the tension of the fluid surface. Consequently, the tips of water-walking insect’s legs are shaped like spheres. |
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What are solutes?
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Solutes = Substances that dissolve in liquid
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What are solvents?
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Solvents = Liquids that dissolve solutes
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What is a solution?
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Solution = Solute + solvent
• Not All Molecules Dissolve in Aqueous Solutions |
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What is the universal solvent?
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Water
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What is the degree of solubility and what are some of its properties?
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• Hydrophilic: Molecules that dissolve easily in water.
o These tend to be polar (either ions or put together with polar covalent bonds) and are often lipophobic (lipid fearing) • Hydrophobic: Molecules that do not dissolve easily in water. o These tend to be nonpolar and are often lipophilic (lipid loving) |
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What are some of the ways to express the concentration of a solution?
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There are Several Ways to Express the Concentration of a Solution
Units used to express the concentration of a solution • Weight is given in grams • # of molecules in moles • # of solute ions in equivalents • volume as liters or milliliters |
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What is a mole?
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Mole: 6.02 x 1023 atoms (Avogadro’s number)
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What is Molarity?
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Molarity: number of moles of solute per liter. Abbreviated mol/L or M
• Ex. 1 molar solution of glucose = 180 grams of glucose in 1 liter of water |
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How do u make a percent solution and which units do you use?
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The metric system is a great system since 1 milliliter (ml) of water equals one gram.
• Thus, a 100 ml of water equals 100 grams of water. Now, you just need to make a percentage based 100. 10% solution = 10 parts solute / 100 parts total solution |
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The concentration of hydrogen ions in the body is expressed in what units?
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The concentration of Hydrogen Ions in the Body is expressed in pH units
pH: Power of hydrogen ions (H+) • Concentration H+ of determines body pH pH = 1/log [H+] [∫ Appendix A] |
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What is acid and its pH?
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Acids: Characterized by a pH of less than 7 (the lower the number, the more acidic).
• They are often defined as molecules that ionize and release a H+ |
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What are base and what is its pH level?
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Bases: Characterized by a pH of greater than 7 (the higher the number, the more basic).
• They are often defined as molecules that ionize and combine with H+ |
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What are buffers?
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Buffers in the body prevent large increases in the [H+], so they help stabilize pH.
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What are biomolecules?
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Organic molecules contain carbon (C).
Other important elements for biomolecules: oxygen (O), hydrogen (H) (and nitrogen (N), phosphorous (P) Sulfur (S)). |
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What is the most abundant molecule and what are its properties?
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Carbohydrates are the most abundant type of biomolecule
• Always CH20 • polar • 4 calories/gram • fundamental unit = monosaccharides |
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What are some simple sugars and its properties?
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Simple sugars: Monosaccharides and disaccharides
• Examples of simple sugars: Mono: Ribose, glucose Di: sucrose • Function: many, but important energy source Complex sugars: Polysaccharides • Ex: Glycogen, starch, cellulose, chitin (all just repeating units of glucose) • Function: Energy source, structural component (cellulose) |
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What are lipids and their properties?
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Lipids are made mainly of Hydrogen and Carbon
• Always CHO (but in varying amounts) • nonpolar • 9 calories/gram • fundamental unit = fatty acids Lipids (fats and oils) and related molecules Lipids: are composed of glycerol and fatty acid chains; also cholesterol derivatives and other molecules. Mono-, di-, or triglycerides have fatty acids linked to glycerol • Function: energy source |
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What are phospolipids?
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Phospholipids
• A triglyceride where one of the fatty acids has been replaced by a phosphate group. • Function: component of cell membranes |
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What are steroids?
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Steroids (derived from cholesterol)
• Functions: component of cell membranes, form hormones |
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What are eicosanoids?
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Eicosanoids
• Form prostaglandins which function as chemical messengers |
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What are proteins and its properties?
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Proteins are the most versatile of the Biomolecules
• Always CHON • polar • 4 calories/gram • fundamental unit = amino acid (20 naturally occurring in proteins) Composed of large amino acids chains called polypeptides • There are amino acids that do not occur in proteins—homoscysteine, GABA, creatine, etc. |
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What is the structure of proteins?
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Structure of proteins: Primary, secondary, tertiary and quaternary
• Functions: Structural component (collagen), enzymes, o forms hemoglobin, hormones, neurotransmitters, antibodies, carries for cholesterol |
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What are conjugated proteins?
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Some molecules combine carbohydrates, proteins, and lipids
Conjugated proteins: proteins combined with carbohydrates and/or lipids |
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What are the properties of nucleotides?
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Nucleotides Transmit and Store Energy and Information
• Always CHONP • polar • 0 calories/gram • fundamental unit = nucleotides Composed of one or more phosphate groups, a five carbon sugar and a nitrogenous base Many types of nucleotides: ATP, cyclic AMP, NAD, FAD, DNA, RNA. • Functions: information storage and energy carriers |
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What is Cytology, histology, and who were the people whom helped bring about cytology?
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A. Cytology = Study of cells
B. Histology = Study of tissues C. Short history of cytology 1. Van Leeuwenhoek and Hooke |
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What are the four principle parts of cells?
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The cell is made up of four principle parts:
• Cell Membrane – protects cell, gives support and separates it from the external environment • Organelles – specialized sections of the cell that perform unique functions • Cytosol – liquid portion of the cell (intracellular fluid) allows reactions to occur • Inclusions – things that can be found in a cell, but do not need to be there (ex: glycogen and melanin) |
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What is a cell membrane?
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• Cell Membrane – protects cell, gives support and separates it from the external environment
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What is an organelle?
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• Organelles – specialized sections of the cell that perform unique functions
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What is Cytosol?
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• Cytosol – liquid portion of the cell (intracellular fluid) allows reactions to occur
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What is inclusions?
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• Inclusions – things that can be found in a cell, but do not need to be there (ex: glycogen and melanin)
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What is the purpose of a cell membrane?
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The Cell Membrane Separates the Cell from Its Environment
A. Phospholipid bilayer with associated proteins and integral proteins (some of which are membrane-spanning) B. Separates extracellular fluid from the inside of cell. C. Has lipid, carbohydrate and protein components. 1. Lipids • phospholipids (make membrane selectively permeable) • cholesterol (keep membrane flexible) • sphingolipids (important in certain membranes may have phospholipid or glycolipid heads) 2. Proteins • peripheral (on ends) • integral (spans across membrane) • lipid anchored proteins (lipid rafts that “float” above the membrane that are associated with sphingolipids and can develop different properties) 3. Carbohydrates – glycolipids and glycoproteins serve as cell recognition sites and in cellular communication |
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What are some of the properties of lipids?
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• phospholipids (make membrane selectively permeable)
• cholesterol (keep membrane flexible) • sphingolipids (important in certain membranes may have phospholipid or glycolipid heads) |
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What are some of the properties of Proteins?
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• peripheral (on ends)
• integral (spans across membrane) • lipid anchored proteins (lipid rafts that “float” above the membrane that are associated with sphingolipids and can develop different properties) |
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What are some of the properties of Carbohydrates?
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. Carbohydrates – glycolipids and glycoproteins serve as cell recognition sites and in cellular communication
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The cystosol includes what?
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The Cytoplasm Includes Cytosol and Organelles
A. Cytoplasm = All material inside cell except nucleus B. Organelles = “little organs” 1. Nonmembranous: Direct contact with cytosol 2. Membranous: One or more phospholipid membranes |
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What is cytoplasm?
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Cytoplasm = All material inside cell except nucleus
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What are organelles?
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Organelles = “little organs”
1. Nonmembranous: Direct contact with cytosol 2. Membranous: One or more phospholipid membranes |
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What are some properties of non membranous organelles?
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Nonmembranous Organelles Are in Direct Contact with the Cytosol
A. 2 groups: 1. Those made from RNA and protein (ribosomes, vaults) 2. Those made from insoluble protein fibers (cytoskeleton, centrosomes, centrioles, cilia, flagella) |
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What are protein derived organelles and its properties?
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Protein Derived Organelles
There are Three Sizes of Protein Fibers in the Cytoplasm A. Cytoplasmic protein fibers include: microfilaments, intermediate filaments, and thick filaments B. Protein monomers involved in protein filaments: |
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What are some of the properties of the cytoskeleton?
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The Cytoskeleton Is a Changeable Organelle
A. Cytoskeleton = Flexible, changeable 3-D scaffolding extending through cytoplasm B. Composed of microfilaments, intermediate filaments, and thick filaments C. Associated with mechanical support, position of organelles, transport of material, cell linkage, cell motility |
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What are Cilia and Flagella?
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Cilia and Flagella Are Movable Hair-like Structures
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What is Cilias properties?
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Cilia: Short, hair-like structures projecting from cell surface
1. Cover surface of cell 2. Movement: sweep fluid secretions across cell surface |
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What is Flagella and its properties?
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Flagella: Longer than cilia
1. one or 2 per flagellated cell 2. Propel cell through fluid |
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What is membranous organelles and its properties?
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Membranous Organelles - Compartments for Specialized Functions
A. Membranous organelles separated from cytosol by one or more phospholipid membranes similar to cell membrane. 1. Many membranous organelles have hollow interior (lumen). 2. Mitochondria, the endoplasmic reticulum, the Golgi apparatus, lysosomes, and peroxisomes B. Membrane barrier allows for separation 1. Separate harmful substances from other cell areas 2. Separate function from other cell areas |
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What is mitochondria and its properties?
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Mitochondria Are the Powerhouse of the Cell
A. Small spherical to elliptical organelle with double wall 1. Outer membrane 2. Inner membrane: Folds into cristae 3. Intermembrane space: Space between the 2 membranes important. in ATP production 4. Matrix: Center of the mitochondrion—within inner membrane a. Contains enzymes, ribosomes, granules, DNA B. Makes ATP through oxidative phosphorylation (i.e. has to have oxygen present) C. Example of symbiotic evolution D. Two characteristics unusual in organelles: 1. Mitochondrial DNA and ribosomes can manufacture their own proteins 2. Mitochondrial DNA allows mitochondrial replication |
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What is the endoplasmic Reticulum and its properties?
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The Endoplasmic Reticulum Is the Site of Protein and Lipid Synthesis
A. Endoplasmic reticulum is a continuation of the outer nuclear membrane. B. Network of interconnected, membranous tubes of two types: 1. Smooth ER (SER) lacks ribosomes. Synthesize lipids, steroids and fatty acids 2. Rough ER (RER) has ribosomes attached to cytoplasmic surface. Proteins made on ribosomes are inserted into lumen of ER 3. Both RER and SER store Ca2+ |
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What is the golgi apparatus and its properties?
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The Golgi Apparatus Packages Proteins into Membrane-Bound Vesicles
A. Structure composed of 1. 5-6 hollow curved sacs B. “IIntracellular UPS” - Modifies proteins and sorts them into secretory or storage vesicles 1. Receives substances from ER 2. Enzymes modify proteins 3. Secretory vesicles: Hold proteins to be exported out of cell 4. Storage vesicles: Never leave cytoplasm |
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What are lysosomes and its properties?
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Lysosomes Are the Intracellular Digestive System
A. Lysosomes: Small spherical storage vesicles 1. Appear as dark membrane-bound granules B. Contain digestive enzymes 1. pH of lysosome interior: 4.8-5.0 2. Membrane separates powerful digestive enzymes from cytoplasm a. Damaged cells release lysosome components → self-destruction (autolysis) |
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What are peroxisomes and its properties?
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Peroxisomes Contain Enzymes That Neutralize Toxins
A. Peroxisomes: Storage vesicles smaller than lysosomes B. Main function: Degrade long-chain fatty acids C. Contain enzymes that digests hydrogen peroxide that is made during this process |
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What is the nucleus?
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The Nucleus Is the Cell’s Control Center
A. Structure 1. Nuclear envelope: 2 membrane structure separating nucleus from cytoplasm 2. Outer membrane connected with ER by pores 3. Nuclear pore complexes restrict movement of large molecules B. Contains DNA: Genetic material C. Contains nucleoli, with genes and proteins controlling ribosomal RNA synthesis |
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What do students tend to confuse about the membranes in the body?
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MEMBRANES IN THE BODY
A. Don’t confuse the different “membranes in the body. 1. Cell membrane or plasma membrane = phospholipid bilayer that surrounds the cell 2. Membrane can mean epithelial tissues that line a cavity or two compartments. |
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What are some properties of cell membranes?
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CELL MEMBRANES
A. Already discussed in section on cells B. General function of membranes 1. Physical isolation 2. Regulation of exchange with environment 3. Communication between cell and its environment 4. Structural support C. Types of gated channels: 1) Chemically gated channels: specific ligands open or close channel 2) Voltage-gated channels: electrical state of cell opens or closes 3) Mechanically gated channels: physical force opens or closes 4) Time gated channels. some specific unit time elapses before they change configuration 5) Light gated channels. change their configuration based on exposure to photons of light |
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What are some properties of body fluid compartments?
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BODY FLUID COMPARTMENTS
A. Few cells are in direct contact with the outside world; most are surrounded by extracellular fluid B. Total Body Water (TBW) = 42 liters (60% of body weight is water) B. Two main compartments: 1. Intracellular fluid (ICF): fluid inside cells (2/3 or about 28 liters) 2. Extracellular (ECF): fluid outside cells (1/3 or about 14 liters) a. Interstitial fluid: fluid directly bathing cells; lacks plasma proteins (11 liters) b. Plasma: fluid portion of blood (3 liters) c. Transcellular fluid. fluid not in any other place (CSF, intraocular fluid, synovial fluid, etc.) |
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What are some properties of movement across a membrane?
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MOVEMENT ACROSS MEMBRANES
A. Membrane composition determines which molecules move across B. Membranes are selectively permeable 1. Permeable molecules: cross membrane by any method (need to be small, uncharged, nonpolar and lipophilic) 2. Impermeable molecules: cannot cross membrane (must get across by another means – help of a protein) C. Factors influencing molecule permeability: 1. Size – only small molecules can fit through the lipid bilayer 2. Lipid solubility or polarity – need to be nonpolar D. How molecule move across membranes 1. Passive transport: does not require outside energy – direct, through a channel or uses transport protein 2. Active transport: requires energy input (ATP) – direct or indirect usage of ATP |
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What are some properties of passive transport?
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Passive Transport
A) Simple diffusion - movement of like substances from an area of high to low concentration. B) Diffusion through a membrane (Fick’s Law) - movement of like substances through a semipermeable membrane from an area of high to low concentration. Determined by the factors in Fick’s law. C) Diffusion through channels - movement of like substances through protein channels in the membrane from an area of high to low concentration. This depends on the number of channels present and the number of those channels which are open. D) Facilitated diffusion (with transporters) - movement of like substances across the membrane using protein transporters from an area of high to low concentration. Since these transporters are proteins they exhibit the characteristics of specificity, competition and saturation. E) Osmosis (special case of water through a semi-permeable membrane) - movement of water across a semipermeable membrane in response to a concentration gradient. • Water moves from higher water concentrations to lower water concentrations. This means water moves from lower solute to higher solute concentration. • Water then “moves to dilute” an area of concentrated solutes. • Water moves freely until osmotic equilibrium. |
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What are some properties of diffusion?
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Diffusion Uses Only the Energy of Molecular Movement
A. Diffusion = Movement of molecules from area of higher concentration → lower concentration B. Properties of diffusion: 1. Molecules move down concentration gradient 2. Passive process: uses energy of the concentration gradient 3. Net movement continues until system reaches dynamic equilibrium 4. Slower with increasing distance 5. Directly related to temperature 6. Inversely related to molecular size |
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What are some properties of lipophilic molecules that diffuse through the phospolipid bilayer?
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Lipophilic Molecules Can Diffuse through the Phospholipid Bilayer
A. Lipid nature of membrane creates barrier between ECF and ICF B. (Relatively small) Lipophilic substances can cross directly through membrane by simple diffusion C. Properties of simple diffusion across membrane in addition to above 1. Rate depends on lipid solubility 2. Rate proportional to concentration gradient and surface area of membrane 3. Rate is inversely proportional to membrane thickness and membrane resistance D. Fick’s law of diffusion describes simple diffusion across a membrane (F = kpA(Co-Ci) where the net flux is directly proportional to the difference in concentration across the membrane, the surface area of the membrane and the membrane permeability constant). Your book presents it in a different form: rate of diffusion () = (available surface area x concentration gradient) / (membrane resistance x membrane thickness) E. Membrane resistance depends on: 1. Size, lipid solubility of molecule 2. Composition of lipid layer F. Lipophobic molecules require proteins or vesicles to cross membrane |
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What do carrier mediated transport exhibit and its properties?
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Carrier-Mediated Transport Exhibits Saturation, Specificity, and Competition
A. Mediated transport = Movement with aid of carrier protein 1. Passive: facilitated transport 2. Active: active transport B. Three properties of mediated transport: specificity, competition, saturation |
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What are the properties of specificity?
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Specificity
A. Protein carrier moves only one type or family of closely related molecules 1. Ex: GLUT transporters move glucose, mannose, galactose, fructose |
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What are the properties of competition?
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Competition
A. Carrier has preference (or affinity) for certain molecule(s) B. Result: competition for binding C. Competitive inhibitors block carrier but aren’t transported |
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What are the properties of saturation?
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Saturation
A. Saturation occurs when a group of carrier proteins is transporting substrate at maximum rate 1. Depends on number of available carriers and substrate concentration 2. Cells can sometimes increase or decrease the number of available carriers to control substrate movement. B. As substrate concentration increases, transport rate increases until carriers become saturated |
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What is facilitated diffusion and its properties?
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Facilitated Diffusion Is Diffusion That Uses Membrane Proteins
A. Facilitated diffusion: 1. Molecules bind to membrane protein 2. Molecules move down concentration gradient 3. No energy required 4. Obeys laws of simple diffusion 5. Also shows specificity, competition, saturation |
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What is active transport and its properties?
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Active Transport Requires the Input of Energy from ATP
A. Active transport: 1. Proteins move molecules against their concentration gradient a. Disequilibrium is created and maintained 2. Requires energy from ATP B. Protein moves one or more substances: 1. Uniport = Protein that only moves one kind of molecule 2. Cotransporter = Protein that moves more than one molecule at a time a. Symporter: moves molecules in one direction b. Antiporter: moves molecules in different directions |
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What is primary active transport and its properties?
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Primary Active Transport (direct)
A. ATP energy directly fuels transport B. Ex: Sodium-potassium ATPase (many primary active transporters are “ATPases”) 1. Sodium out of cell, potassium into cell 2. Fueled by ATP hydrolysis 3. Helps maintain membrane potential difference by moving ions against their concentration gradient a. Important to many functions, including nervous system function |
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What is secondary transport (indirect) and its properties?
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Secondary active transport (indirect)
A. Secondary active transport uses potential energy stored in a concentration gradient 1. Energy released when one molecule moves down its gradient is used to move another molecule against its concentration gradient 2. No ATP is used directly to fuel transport B. Ex: Na+ -glucose transporter 1. Na+ moves down concentration gradient 2. Glucose against concentration gradient |
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What does it mean when the body is in osmotic equilibrium?
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A. Osmosis = Movement of water across a semipermeable membrane in response to a concentration gradient
1. Water moves from higher water concentrations to lower water concentrations a. This means water moves from lower solute to higher solute concentration b. Water then “moves to dilute” an area of concentrated solutes 2. Osmotic pressure (atm or mmHg) opposes movement of water across a membrane B. Water moves freely until osmotic equilibrium (Fig. 5-31b) Osmolarity Describes the Number of Particles in Solution A. Osmolarity 1. Osmolarity describes the number of particles per liter of a solution a. Osmoles per liter = osmol/L or OsM or b. Milliosmoles/ liter (mOsM/L) 2. Osmolarity takes into account dissociation of molecules in solution 3. Convert molarity to osmolarity a. Osmolarity (osmol/L) = molarity x (number of particles/molecule in solution) 4. Osmolality a. Osmoles per kilogram = osmol/kg solvent (H2O) |
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What is osmolarity and its formula?
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Osmolarity describes the number of particles per liter of a solution
a. Osmoles per liter = osmol/L or OsM or b. Milliosmoles/ liter (mOsM/L) |
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How do you convert molarity in osmolarity?
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Convert molarity to osmolarity
a. Osmolarity (osmol/L) = molarity x (number of particles/molecule in solution) |
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What is osmolality?
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Osmolality
a. Osmoles per kilogram = osmol/kg solvent (H2O) |
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How do you compare osmolarities of two solutions?
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Comparing Osmolarities of Two Solutions
A. How to compare osmolarities of two solutions B. Solutions may be isosmotic, hyperosmotic, or hyposmotic: 1. Isosmotic: 2 solutions have same number of particles/unit volume 2. Hyperosmotic: Osmolarity of solution A > osmolarity solution B, so A hyperosmotic to B 3. Hyposmotic: From above, solution B is hyposmotic to solution A C. Osmolarity is a colligative property: 1. Depends solely on the number of particles per liter solution |
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What are the properties of tonicity?
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The Tonicity of a Solution Describes How the Size of a Cell Would Change If It Were Placed in the Solution
A. Tonicity describes how cell volume would change if placed in solution 1. Tonicity does not describe osmolarity and has no units; always comparative B. Terms used to describe changes in tonicity: isotonic, hypertonic, hypotonic 1. Isotonic: Cell volume doesn’t change 2. Hypertonic: Cell volume decreases when placed in solution 3. Hypotonic: Cell volume increases when place in solution C. Tonicity depends on nature of solutes, not on osmolarity: 1. Penetrating solutes: Can enter cell (urea; glucose is slowly penetrating) 2. Nonpenetrating solutes: Cannot enter cell (sucrose, NaCl) D. To determine tonicity: 1. Determine relative concentrations of nonpenetrating solutes in solution and in cell a. Water will move to dilute nonpenetrating solutes b. Penetrating solutes will then distribute to equilibrium 2. Now decide how the cell volume will change (tonicity) |
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What does it mean when the body is in a state of electrical equilibrium?
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The Body Is in a State of Electrical Disequilibrium
A. Results of chemical disequilibrium 1. Major intracellular ions: K+, phosphate 2. Extracellular ions: Na+, Cl- 3. Creates electrical disequilibrium—resting membrane potential difference |
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What is Ficks Law?
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Fick’s Law of Diffusion is concerned with the diffusion of substances directly across the cell membrane. It is described by the equation:
Net Flux Rate = available surface area x concentration gradient / membrane resistance x membrane thickness |
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Give and example of applying Fixx law- using this problem.
A. An experimental drug is given that increases the membrane resistance to oxygen of mitochondria by fourfold. What happens to the diffusion rate of oxygen into the mitochondria? |
Since the drug increased membrane resistance by fourfold, we take our basic equation and make the appropriate changes. Thus:
Net Flux Rate = available surface area x concentration gradient / membrane resistance x membrane thickness Net Flux Rate = 1 x 1 / 4 x 1 = ¼ We know that membrane resistance is inversely proportional to the net rate of flux, so the flux should decrease. Therefore, we can say that the qualitative change was a decrease in the net flux while the quantitative change was ¼. |
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Explain ficks law of diffusion?
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Thus, the rate of diffusion is directly proportional to available surface area x concentration gradient. This means that if either of these variables increase, the net flux will also increase as well. The rate is also inversely proportional to the membrane resistance x membrane thickness. Thus, increases in these variables will result in a decrease in net flux. We will use the basic model to make quantitative assessments as well. The problems indicate that only one variable changes so we will assume that the others are equal to the value of one (1). If we change the appropriate variable by the amount stated in the problem, we can make accurate assessments of the quantitative changes.
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