Bil 265, Physiology, Fall 2006 - Third Examination - Form 1

1. Suppose that the diffusion constant of oxygen gas in air is 0.167 cm²/sec (at 37 degrees C), a reasonable approximation to the actual value. On the average, how far might you expect an oxygen molecule to diffuse in air in 9 seconds? Always choose the best or closest answer.

1) 1.5 cm

2) 3.0 cm

3) 9.0 cm

4) 36.0 cm

5) 53.0 cm

Correct Answer is: 2

2. The diffusion constant of oxygen gas in air is 0.167 cm²/sec (at 37 degrees C). What is the approximate diffusion constant of oxygen gas in water (intracellular contents)? Always choose the best or closest answer.

1) 0.00001 cm²/sec

2) 0.167 cm²/sec

3) 3.24 cm²/sec

Correct Answer is: 1

3. We discussed the diffusion of oxygen gas from the center of a human alveolus, through the epithelial cells separating the alveolar sacs from the blood plasma in a capillary, and finally from wall of a capillary to the center of the capillary. Which of these three steps is the rate-limiting (slowest) step of the three?

1) diffusion of oxygen gas from the center of a human alveolus to the surface of the alveolus

2) diffusion through the epithelial cells separating the alveolar sacs from the blood plasma in a capillary

3) diffusion from wall of a capillary to the center of the capillary.

Correct Answer is: 3

4. Which best describes the Haldane effect?

1) The Haldane effect promotes greater binding of oxygen to hemoglobin when oxygen molecules are already bound to one or more of the subunits of hemoglobin.

2) The Haldane effect promotes release of carbon dioxide from bicarbonate in the presence of oxygen.

3) The Haldane effect promotes dissociation of oxygen from hemoglobin in response to a decrease in pH (say, 7.6 to 7.2).

4) The Haldane effect delays the onset of a muscle twitch because of compression of the series elastic element.

5) The Haldane effect doesn't exist. Choose this answer if the Haldane effect is just a construction of your instructor's imagination or doesn't have anything to do with physiology.

Correct Answer is: 2

5. Which best describes the Bohr effect?

1) The Bohr effect promotes greater binding of oxygen to hemoglobin when oxygen molecules are already bound to one or more of the subunits of hemoglobin.

2) The Bohr effect promotes release of carbon dioxide from bicarbonate in the presence of oxygen.

3) The Bohr effect promotes dissociation of oxygen from hemoglobin in response to a decrease in pH (say, 7.6 to 7.2).

4) The Bohr effect doesn't exist. Choose this answer if the Bohr effect is just a construction of your instructor's imagination or doesn't have anything to do with physiology.

Correct Answer is: 3

6. Which best describes the Rasetti effect?

1) The Rasetti effect promotes greater binding of oxygen to hemoglobin when oxygen molecules are already bound to one or more of the subunits of hemoglobin.

2) The Rasetti effect promotes release of carbon dioxide from bicarbonate in the presence of oxygen.

3) The Rasetti effect promotes dissociation of oxygen from hemoglobin in response to a decrease in pH (say, 7.6 to 7.2).

4) The Rasetti effect doesn't exist. Choose this answer if the Haldane effect is just a construction of your instructor's imagination or doesn't have anything to do with physiology.

Correct Answer is: 4

7. TRUE or FALSE: The Antarctic Icefish has no hemoglobin in its blood at all!

1) True.

2) False.

Correct Answer is: 1

8. TRUE or FALSE: Both human glucagon and human insulin use a Ras protein as part of the internal signaling pathway in vertebrate liver cells.

1) True.

2) False.

Correct Answer is: 2

9. Which of the following is the amino acid that is pulled closer to the plane of the porphyrin ring when an oxygen molecule binds to hemoglobin?

1) cysteine.

2) tyrosine.

3) glutamine

4) histidine

Correct Answer is: 4

10. Which of the following is most accurate?

1) The three-chambered heart of amphibians has two ventricles and one atrium.

2) The squid has separate heart chambers to pump blood to the gills and pump blood to the systemic circulation.

3) In a fish heart, blood flows first into a ventricle and then immediately into an atrium.

4) Some lizards have a separation part way up the one large atrium.

Correct Answer is: 2

11. Which organism would most likely have a "brachial heart"?

1) octopus.

2) frog.

3) teleost.

4) shark.

Correct Answer is: 1

12. Which of the following best describes the particularly useful characteristic of hemoglobin having a sigmoid (S-shaped) oxygen binding curve (% oxygen bound vs. partial pressure of oxygen)?

1) Hemoglobin binds a large amount of oxygen, even at very low oxygen pressures.

2) The maximum amount of oxygen that can be bound for each of the four protein chains is less than if the four protein chains of hemoglobin were separated.

3) Oxygen is released at reasonably high oxygen pressures, before the oxygen pressure drops so low as to starve cells of oxygen.

Correct Answer is: 3

13. What causes "tetanus"?

1) low Calcium.

2) repetitive stimulation of a muscle with a series of closely spaced action potentials.

3) low ATP.

4) a change in pH after death.

Correct Answer is: 2

14. What causes "rigor"?

1) low Calcium.

2) repetitive stimulation of a muscle with a series of closely spaced action potentials.

3) low ATP.

4) a change in pH after death.

Correct Answer is: 3

15. In the lecture notes, the statement is made: "The frequency of pacemaker potentials decreases upon _____ stimulation by the _____ and increases by _____ stimulation." Fill in the blanks:

1) sympathetic, vagus, parasympathetic

2) parasympathetic, celiac, sympathetic

3) sympathetic, celiac, parasympathetic

4) parasympathetic, vagus, sympathetic

Correct Answer is: 4

16. Which of the following are cells that are most active in secreting protein surfactant in the human bronchioles?

1) goblet cells.

2) Bowman's cells.

3) Clara cells.

4) Harvey cells.

5) Mildred cells.

Correct Answer is: 3

17. The thin filaments that attach directly to the Z-disk of human skeletal muscle are comprised primarily of:

1) myosin.

2) tubulin.

3) kinesin.

4) dynein.

5) actin.

Correct Answer is: 5

18. What color is hemocyanin when deoxygenated?

1) red.

2) brown.

3) blue

4) colorless

Correct Answer is: 4

19. During skeletal muscle contraction, calcium is released from the:

1) nucleus

2) mitochondria

3) lumen of the sarcoplasmic reticulum

4) lumen of the T tubules

5) lysosomes

Correct Answer is: 3

20. Which best describes the Lohman reaction?

1) Release of carbon dioxide bound to hemoglobin.

2) The Lohman reaction takes pyruvate and converts it to lactate, in the absence of oxygen.

3) Reactions involving phosphorylation and dephosphorylation of creatine.

4) Converts carbon dioxide gas to bicarbonate.

Correct Answer is: 3

21. In what form is MOST carbon dioxide carried from the peripheral tissues to the lung, in the human?

1) bicarbonate ion bound to hemoglobin.

2) carbon dioxide gas dissolved in the blood plasma.

3) bicarbonate dissolved in interior of red blood cells or the blood plasma.

4) carbonic acid dissolved in interior of red blood cells or the blood plasma.

Correct Answer is: 3

22. What ion is used to bind oxygen gas in invertebrate hemocyanins?

1) magnesium

2) zinc

3) maganese

4) iron

5) copper

Correct Answer is: 5

23. What is chlorocruorin?

1) a receptor tyrosine kinase.

2) a medication used to treat ventricular fibrillation.

3) used to help some animals make enough ATP to power their muscles.

4) an oxygen binding pigment.

Correct Answer is: 4

24. The "chloride shift" in red blood cells

1) results in cotransport of chloride in one direction and sodium in the other direction.

2) occurs when bicarbonate moves out of red blood cells.

3) is catalyzed by the enzyme carbonic anhydrase.

4) occurs in the Antarctic Icefish but not in humans.

Correct Answer is: 2

25. Which of the following is most accurate with respect to tetanus in mammalian cardiac muscle?

1) Tetanus doesn't occur because the action potentials on heart muscle cells are much shorter in duration than on other types of muscles.

2) Tetanus doesn't occur because the action potentials on heart muscle cells are much longer in duration than on other types of muscles.

3) Tetanus doesn't occur because heart muscle has so much myoglobin that ATP concentrations can never fall to low levels.

4) Heart muscle is always in tetanus as a normal part of its contraction.

Correct Answer is: 2

26. Suppose that a vertebrate, striated skeletal muscle cell is prevented from contracting, so that actin and myosin can't bind to each other, as during a normal contraction. Under these conditions, which of the following is true with respect to actin ATPase activity?

1) Actin ATPase activity still occurs, but at a lower rate than in contracting muscle.

2) Actin ATPase activity occurs, but at a higher rate than in contracting muscle.

3) Significant actin ATPase activity occurs, at the same rate as in contracting muscle.

4) Actin doesn't have any significant ATPase activity, either in contracting or noncontracting muscle.

Correct Answer is: 4

27. Which of the following is a hormone that is produced in the supraoptic nucleus of the hypothalamus and released from the posterior pituitary?

1) antidiuretic hormone.

2) insulin.

3) oxytocin.

4) lutenizing hormone

Correct Answer is: 1

28. Which of the following is the protein that physically blocks the contact of actin and myosin in relaxed human skeletal muscle?

1) troponin.

2) desmin.

3) alpha-actinin.

4) tropomyosin.

5) dynein.

Correct Answer is: 4

29. Which of the following is the protein that binds calcium for activation of human skeletal muscle?

1) troponin.

2) desmin.

3) alpha-actinin.

4) tropomyosin.

5) dynein.

Correct Answer is: 1

30. A human patient is being treated with Lithium. In MODERN medical practice, what condition is most likely being treated with Lithium?

1) Bipolar disorder.

2) IDDM.

3) NIDDM.

4) Neurogenic diabetes insipidus.

Correct Answer is: 1

31. Which of the following might I most likely give you if I hit you on the head?

1) Bipolar disorder.

2) IDDM.

3) NIDDM.

4) Neurogenic diabetes insipidus.

Correct Answer is: 4

32. TRUE or FALSE: The hormone Insulin is a protein.

1) True.

2) False.

Correct Answer is: 1

33. TRUE or FALSE: The hormone Epinephrine is a protein.

1) True.

2) False.

Correct Answer is: 2

34. Which of the following receptor and internal cell signaling systems is used by human growth hormone binding to target cells?

1) G-protein and cAMP.

2) G-protein and inositol phospholipids.

3) Receptor tyrosine kinases.

Correct Answer is: 3

35. Where would we most likely find an infundibulum?

1) in the brain.

2) in the liver.

3) in an invertebrate circulatory system.

4) in the human lung.

Correct Answer is: 1

36. Where would we most likely find the pores of Kohn?

1) in the brain.

2) in the liver.

3) in an invertebrate circulatory system.

4) in the human lung.

Correct Answer is: 4

37. You have returned home for the holidays. To celebrate, your family prepares a turkey dinner. As you are eating the white meat of the turkey, you might correctly state: (IMPORTANT - Note that all answers start with "Delicious". You must choose one of these answers since you would not want to say "Yuk" at the holiday dinner table.)

1) "Delicious! These are slow twitch muscle fibers and thus use ATP at a relatively high rate."

2) "Delicious! These are slow twitch muscle fibers and thus use ATP at a relatively low rate."

3) "Delicious! This meat contains mostly fast-twitch oxidative fibers."

4) "Delicious! White meat contains many mitochondria which sustain the rapid flying of muscles of turkeys."

5) "Delicious! White meat contains few mitochondria and depends a lot on glycolysis to produce ATP."

Correct Answer is: 5

38. Human skeletal muscle produces the most power when:

1) when the muscle is shortening, but at less than maximum velocity.

2) when the muscle is shortening at maximum velocity.

3) the muscle is pulling against an fixed object and the muscle can't shorten.

Correct Answer is: 1

39. Suppose for a human, the cellular receptors for insulin are destroyed. Which of the following best describes this condition?

1) Type 1 diabetes insipidus.

2) Type 2 diabetes insipidus.

3) Type 1 diabetes mellitus.

4) Type 2 diabetes mellitus.

Correct Answer is: 4

40. Suppose for a human, the pancreas produces much less insulin than normal. Which of the following best describes this condition?

1) Type 1 diabetes insipidus.

2) Type 2 diabetes insipidus.

3) Type 1 diabetes mellitus.

4) Type 2 diabetes mellitus.

Correct Answer is: 3