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Unformatted text preview: FORM 1 FIRST TEST
SPRING 2006 l. We observe that when invertebrate c ells, like those of a copepod, are placed a
lower salinity medium, ammonia excretion increases. What is happening ?
a. more amino acids are metabolized and cellular osmolarity is
b. more amino acids are produced within the cell
c. Sodium is rapidly transported from the cell
d. the Krebs cycle essentially runs backwards
e. NAD+ is replenished
2. When oxygen is not present, lactate is produced in muscle cells. What is the
function of this reaction, and why is it necessary for metabolism ?
a. lactate increases the cells’ osmolarity
b. NADH is replenished
c. electrons are harvested for energy
d. NAD+ is replenished
3. Two isozymes of LDH have different Kms for pyruvate. Form 1 has a Km of 0.3
mM pyruvate and Form 2 has a Km of 0.5 mM pyruvate. At 0. 25 mM pyruvate,
which has the higher reaction rate ?
a. Form 1
b. Form 2
c. impossible to tell from the data given
d. both are the same
4. Three digestive enzymes, trypsin, chymotrypsin and pepsin all degrade protein.
Which one has the highest reaction velocity at pH 3.0 ?
d. all are equal
e. trypsin and chymotrypsin
5. Why is myoglobin an affective intracellular store for oxygen ?
a. it has a much higher Km for oxygen than hemoglobin
b. it has a much lower Km for oxygen than hemoglobin
c. it is too large a molecule to leave the cell
d. is has a much lower affinity for oxygen than hemoglobin.
6. In energy catabolism, electrons are harvested and shuttled to the electron
transport chain. In what part of the cycle are the most electrons harvested ?
c. Krebs cycle d. all are equal in the number harvested.
7. For red muscle fibers, which of the following are true ?
a myoglobin levels are higher than in white muscle
a. lactate build up is less than in white muscle
b. the density of mitochondria is greater than white muscle
c. all are true
d . a, b, and c are false
8. For an animal muscle cell, or nerve cell, which statement is true
a. sodium concentration inside is greater than outside
b. potassium concentration inside is greater than outside
c. both sodium and potassium are higher outside
d. both sodium and potassium are higher inside
9. In digestion, bicarbonate is secreted by
a. the stomach
b. the pancreas
c. the gall bladder
d. the small intestine
a. gastrin b. CCK or Cholycystokinin c. secretin d. HCl 10. Activates pepsin -d
11. increases the release of bile salts from the gall bladder --b
12. stimulates the pancreas and inhibits gastrin secretion--c
13. stimulates parietal cells to secrete HCl --a
14. Glycerol has an olive oil/water partition coefficient of 0.0001, ethyl urea is 0.002
and ethanol is 0.05. Which one crosses a lipid bilayer mo re easily ?
a. ethyl urea
d. all are small molecules and cross equally
e. none of these can cross a membrane without a pore
15. In the shark rectal gland (and the human tracheal epithelium), chloride moves
across the apical surface of the tissue. What type of transport is involved ?
c .active transport
d.exocytosis 16. Which of the following would stabilize a membrane in a high temperature
a. higher cholesterol
b. higher unsaturated fats
c. lower cholesterol
d. lower protein
17. Where is most of the water absorbed along the digestive tract ?
a. the stomach
b .the upper small intestine
c .the lower small intestine
d .the large intestine
18. Which of the following is not true o f manatee digestion ?
a. gut passage time is much longer than in humans
b. the digestive tract is much shorter than in humans
c. cellulose is the main ingredient of the diet
d. methane is one of the products of digestion
19. Can an enzyme alone change the direction of a reaction ?
20. In biological systems reactions that don’t require ATP would occur without
enzymes, but they would occur very slowly.
21. The enzyme LDH catalyzes
a. the conversion of pyruvate to lactate
b. the conversion of pyruvate to PEP
c. the conversion of lactate to carbon dioxide and water
d. the conversion of lactate to acetyl CoA
22. Facilitated diffusion
a. requires no ATP
b. is always down a concentration gradient
c. requires a carrier
d. displays saturation kinetics
e .all of these
23. The respiratory quotient is
a. the ratio of oxygen consumed to carbon dioxide released
b. the ratio of carbon dioxide released to oxygen consumed
c . the amount of heat given off in calories
d. the amount of energy generated by a molecule of oxygen 24. Homeothermic mammals radiate energy in the infra-red range
25. Smaller animals need to eat more per gram of animal than larger animals
26. On a log/log plot of metabolic rate vs size of the animal. The slope of the line is
a. - .75
c . -.25
27 .If a development pattern is allometric, then
a. as a limb doubles in length, it also doubles in diameter
b. proportions of an animal change as it grows larger
c . stresses on legs and arms increase with size 2
28. Specific dynamic action refers to
a. the highest metabolic rate that an animal shows
b. the metabolic rate when an animal is burning its oxygen debt
c. the increase in metabolic rate after eating
d . the decrease in metabolic rate
29. The energy of activation of a reaction is decreased as temperature increases
30. Which material provides the best insulation
b. human flesh
c. fox fur d. still air 31. What is an example of the use of conduction to regulate temperature ?
a. a dog panting
b. a fan blowing across your face
d .dilation of face capillaries on a warm day
32. The Q10 for most biological reactions is
a. .5 to 1
b. b. 2-3
c . near 5
33. According to the Michaelis Menten equation, the rate of enzyme activity is
a. linear when the substrate concentration is low
b. directly proportion to the substrate concentration
c. independent of the substrate concentration
34. For homeotherms, the oxygen consumption increases linearly with temperature. a. true b. false 35. . Brush border enzymes of the small intestine
a. function to break down mucus in the digestive tract
b. inactive bacteria
c. activate other digestive enzymes
d. form ion channels in the membrane
36. The rate of gill ventilation of oscars(fish) in Lake Osceola follows the Q10 rules
for metabolic rate. If the fish ventilates 20 times per minute at 18oC, what is the
rate at 28oC ?
a. 20 times per minute
b. 30 times per minute
c. 40 times per minute
d. 10 times per minute
37. The average kinetic energy of a population of molecules increases 2-3% for every
increase of 10oK. How does this change the enrgy of activation needed by these
molecules for reaction ?
a. there is no change in the energy of activation
b. the energy of activation must be 2-3% greater
c. the energy of activation must be 2-3x greater
d. the energy of activation is reduced 2-3%.
38. Metabolic rate changes with temperature. The rate change in endotherms is
about twice as steep as the rate change in ectotherms
39. Which statement is true ?
a. a dog uses more oxygen/ unit time than a shrew
b. a gram of dog uses more oxygen per unit time than a gram of shrew
c. a dog looses more heat per gram than a shrew
d. all are true
40. The key to the survival of the “frozen” frog is the fact that
a. it froze from the inside out
b. it thawed from the inside out
c. it thawed uniformly
d. the lungs thawed first
41. Following absorption, amino acids
a. are transported directly to cells
b. are reassembled as proteins in the cells of the villi
c. are transported directly to the liver
d. are oxidized in the cells of the villi
42. Carbon fragments enter the Krebs cycle as
a. 6 carbon sugars
b. 5 carbon sugars
c. 2 carbons + a coenzyme
d. 4 Carbons + a coenzyme 43. Which class of foods produces the greatest amount of heat per mole, when
burned by direct calorimetry ?
d. nucleic acids
44. When faced with an acute temperature change, which type of adaptation usually
occurs first ?
a. enzyme production is increased or decreased
b. metabolism is increased or decreased
c. the organism behaviorally avoids the shift
d. membrane composition changes
45. Where along the digestive tract is aspirin absorbed ?
a. the esophagus
b. the stomach
c. the large intestine
d. the small intestine
46. What is the function of heat stress proteins ?
a. they increase the osmolarity of the cell like an antifreeze
b. they increase the osmolarity of the blood
c. they bind to cell proteins to prevent conformational change
d. they increase the Km of select enzymes in stress Problems
47-48. Planaria are flat worms that depend on diffusion for the cell supply of oxygen.
How thin does a flat worm need to be for oxygen to effectively reach cells in the
center of the animal if the cells demand is 5 moles O2 per minute ?
Ficks first law
Rate of Diffusion = DA ( C1-C2)
The area of the worm surface is 4 cm2, the diffusion coefficient is --------------, and the
water contains --------moles/ml. (Assume cells of the worm have no oxygen). 49-50. On a graph of enzyme velocity vs substrate concentration, show the difference
between straight diffusion and active transport. ...
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- Fall '08