Questions:

1. Which of the following statements about the electron transport chain is NOT correct
  1. It is located in the inner mitochondrion membrane
  2. Cytochrome C accepts electrons from complex II
  3. Cytochrome oxidase (complex IV) accepts electrons from Cytochrome c
  4. Complex I is called NADH dehydrogenase
  5. Coenzyme Q accepts electrons from complex I and complex II
2. Which of the following statements about oxidative phosphorylation is NOT true  (Note! The electron transport chain or electron transfer chain is abbreviated etc.)
  1. The movement of electrons down the etc. only happens if protons are pumped out of the mitochondria
  2. If the proton gradient is too high, electrons will not move through the etc.
  3. A proton gradient is formed across the outer mitochondria membrane
  4. The fee energy of the proton gradient can be used to create high energy bonds
  5. Protons enter the mitochondria via ATP Synthase if, and only if, ATP is synthesized
3. All of the following statements are true EXCEPT
  1. Complex II accepts two electrons from FADH2 of succinate dehydrogenase of the TCA cycle
  2. Complex I donates two electrons to Coenzyme Q
  3. If the ATP/ADP ratio is low enough, the oxidation of succinate will produce about 1.5 ATPs
  4. When succinate is oxidized, protons are pumped at complex I
  5. When succinate is oxidized, protons are pumped at complex III and IV
4. The function of an electron in the electron transport chain is
  1. To transfer energy from complex II to complex I
  2. To pump hydrogen ions using complex II
  3. To use its free energy to pump protons against their concentration gradient
  4. To combine with phosphate when ATP is synthesized
  5. To react with ATP synthase
5. All of the following statements about cytochromes of the electron transport chain are true EXCEPT
  1. They are heme proteins
  2. They serve as electron carriers in oxidation-reduction reactions
  3. They all have the same energy when reduced
  4. When reduced, iron is in the +2 state
  5. When oxidized, iron is in the +3 state
6. Fatigue in iron deficiency anemia may be explained in part by all of the following EXCEPT
  1. A lack of hemoglobin in the blood
  2. An inability to transport oxygen
  3. A lack of cytochromes in the ets.
  4. The inability to synthesize ATP at a reasonable rate.
  5. A lack of Coenzyme Q
7. Cytochrome oxidase
  1. Uses H2O as a substrate
  2. Produces HOOH as a product
  3. Cannot function if oxygen is absent
  4. Accepts electrons from hydrogen ions
  5. Uses ADP and Pi as substrates
8. All of the following are included in the chemiosmotic theory EXCEPT
  1. The movement of electrons is coupled to ATP synthesis in the mitochondria
  2. The etc is coupled to ATP synthesis by a proton gradient
  3. The proton gradient contains the energy to drive the ATP synthase reaction
  4. The energy in the proton gradient is derived from the energy in NADH and FADH2 in the mitochondria
  5. Oxidative phosphorylation is reversible
9. Concerning the generation of ATP by oxidative phosphorylation, all of the following are true EXCEPT
  1. NADH produced in the cytosol of the cell will generate 2.5 ATPs
  2. NADH produced in the mitochondria will generate 2.5 ATPs
  3. NADH produced by the succinate thiokinase reaction will generate 1.5 GTPs
  4. FADH2 produced in the mitochondria will generate 1.5 ATPs
  5. Acetyl CoA entering the TCA cycle will produce 10 ATPs
10. Given that the standard free energy change for oxidative phosphorylation using NADH as a substrate is about a –53 kcal/mole, and that the free energy in the 2.5 moles of ATP generated is -17.5 kcal/2.5 moles, you can conclude all of the following EXCEPT
  1. Only about 33% of the free energy in NADH was used to generate ATP
  2. About 66% of the free energy in NADH was converted to heat
  3. The overall change in free energy of the reaction was –35.5 kcal/mole
  4. Oxidative phosphorylation generates a lot of heat
  5. Oxidative phosphorylation is a reversible reaction
11. All of the following statements about the binding of CN- to the electron transport chain are correct EXCEPT
  1. Oxidative phosphorylation will be inhibited
  2. Electron transport will be inhibited
  3. Proton pumping will be inhibited
  4. Some cytochromes will become oxidized
  5. FADH2 and NADH will not be oxidized
12. A baby is born with congenital lactic acidosis because she has a defective electron transport protein.  This causes a decrease in the rate at which NADH and FADH can be oxidized to produce ATP using oxidative phosphorylation.  You would expect all of the following EXCEPT
  1. The concentration of ADP in the cell would increase and activate glycolysis
  2. Increased glycolysis would produce NADH and pyruvate
  3. The inhibition of the electron transport chain would increase the concentration of NADH
  4. The increased NADH would increase the conversion of pyruvate to acetyl CoA
  5. Increased NADH and pyruvate would be converted to lactate by lactate dehydrogenase
13. All of the following help to explain why shivering produces heat EXCEPT
  1. Muscle contraction requires the generation of heat
  2. The ADP produced must be converted to ATP
  3. Oxidative phosphorylation generates heat
  4. Most of the reactions oxidizing fuels produce heat
  5. In adults, shivering uncouples oxidative phosphorylation
14. Suppose that there is a dramatic increase in the work done by a cell.  You would expect an increase in all of the following EXCEPT
  1. The utilization on oxygen
  2. The ratio of ATP to ADP in the cell
  3. The rate of utilization of ADP by ATP synthase
  4. The entrance of H+ into the mitochondria through ATP synthase
  5. The pumping of H+ out of the mitochondria by the electron transport chain
15. Assume that a cell has a dramatic need to increase the work being done.  You would expect all of the following to lead to activation of the pyruvate dehydrogenase complex EXCEPT
  1. A decrease in the concentration of NADH
  2. A decrease in the concentration of Acetyl CoA
  3. A decrease in the activity of NADH dehydrogenase
  4. An increased activity of the TCA cycle
  5. An increase in ADP
16. Suppose a cell is subjected to high concentrations of Aspirin, T4 or some other chemical uncoupler of oxidative phosphorylation, one would expect an increase in the rate of all of the following EXCEPT
  1. ATP synthesis
  2. Proton pumping by the electron transport chain
  3. Heat generation by the mitochondria
  4. Oxygen utilization by the cell
  5. NADH oxidation by NADH dehydrogenase
17. Comparing the effect of an inhibitor with an uncoupler of oxidative phosphorylation,
  1. The uncoupler would stop the oxidation of NADH by the electron transport chain
  2. The inhibitor would allow electrons to pass through the electron transport chain
  3. The uncoupler would inhibit the reduction of oxygen by the electron transport chain
  4. The inhibitor would increase the pumping of protons by the electron transport chain
  5. The uncoupler would increase heat production by the mitochondria
18. There are many transport systems in the mitochondrial membrane.  One that exchanges ADP for ATP is called a(n)
  1. Antiporter
  2. Symporter
  3. Uniporter
  4. Active Uniporter
  5. Active Transporter
19. Your patient had a heart attack and was administered a vasodilating agent in an effort to reduce her hypertension.  The vasodilating agent will lower all of the following EXCEPT
  1. Rate of utilization of ATP
  2. Mitochondrial proton gradient
  3. Work done by the heart
  4. Chance of cell lysis
  5. Oxygen consumption
20. All of the following statements about TPA are true EXCEPT
  1. TPA stands for tissue plasminogen activator
  2. TPA Is an enzyme
  3. TPA converts fibrinogen to fibrin
  4. Plasmin is a protease that digests fibrin
  5. Plasminogen is a normal constituent of blood
21. One of the following statements is NOT true.  During a heart attack and when the cell is oxygen starved, anaerobic glycolysis will
  1. Be activated by the low oxygen pressure
  2. Be activated by the low ATP to ADP ratio
  3. Produce ATP by oxidative phosphorylation
  4. Produce lactate as an end product of the pathway
  5. Produce H+ and lower the pH
22. Your patient has hyperthyroidism was the result of Graves’ disease.  Assume that some of the symptoms seen result from uncoupling of oxidative phosphorylation.  Compared to a normal person, your patient is doing all of the following EXCEPT
  1. Oxidizing more NADH
  2. Using more oxygen
  3. Pumping more protons
  4. Producing more heat
  5. Eating less food

Answers:

1. Answer: B. Chapter 21 , Objective 1: Objective 1: Be able to draw a cartoon demonstrating oxidative phosphorylation. Include NADH, complexes I, II, III and IV, CoQ, cytochrome c, and ATP synthase. Demonstrate the sites for the pumping of protons and the direction of movement. Indicate the excess protons on one side of the membrane. Draw equations showing the synthesis of H2O and ATP Back to question 1.
2. Answer: C. Chapter 21 , Objective 2: Why does the movement of protons produce ATP? Back to question 2.
3. Answer: D. Chapter 21 , Objective 3: Where is complex II found? What reaction of the TCA cycle does it catalyze? How much ATP is produced when 2 electrons of succinate are passed through the chain to O2? Which complexes couple proton pumping and succinate oxidation? Back to question 3.
4. Answer: C. Chapter 21 , Objective 4: What is the function of an electron in the electron transport chain? Back to question 4.
5. Answer: C. Chapter 21 , Objective 5: What is a cytochrome? Back to question 5.
6. Answer: E. Chapter 21 , Objective 6: Explain how iron deficiency anemia affects oxygen transport in the blood and oxidative phosphorylation in mitochondria. Back to question 6.
7. Answer: C. Chapter 21 , Objective 7: What reaction is catalyzed by cytochrome oxidase? Back to question 7.
8. Answer: E. Chapter 21 , Objective 8: Be able to state the chemiosmotic theory! Back to question 8.
9. Answer: C. Chapter 21 , Objective 9: How many ATPs are synthesized by ATP synthase for each NADH oxidized by the electron transport chain? How many for FAD(2H)? Back to question 9.
10. Answer: E. Chapter 21 , Objective 10: Is oxidative phosphorylation a reversible reaction? Why? Back to question 10.
11. Answer: D. Chapter 21 , Objective 11: What portion of the ETC is inhibited by CN-? What is the effect of cyanide inhibition upon proton pumping and ATP synthesis? Back to question 11.
12. Answer: D. Chapter 21 , Objective 12: Why does an impairment of the electron transport chain result in lactic acidosis? Back to question 12.
13. Answer: E. Chapter 21 , Objective 13: How does shivering generate heat? Back to question 13.
14. Answer: B. Chapter 21 , Objective 14: Be able to go through the series of events whereby increases ATP utilization is coupled to increased O2 utilization. Back to question 14.
15. Answer: C. Chapter 21 , Objective 15: Be able to go through the series of events whereby pyruvate dehydrogenase is activated by increased ATP utilization. Back to question 15.
16. Answer: A. Chapter 21 , Objective 16: Understand how a chemical uncoupler works. What happens to heat production, proton pumping, ATP synthesis, and NADH utilization following uncoupling? Back to question 16.
17. Answer: E. Chapter 21 , Objective 17: What is the difference between an inhibitor of electron transport and an uncoupler of electron transport with respect to NADH utilization, proton pumping, and ATP synthase? Back to question 17.
18. Answer: A. Chapter 21 , Objective 18: Give an example of both a symport and an antiport that functions in the mitochondrial membrane. Back to question 18.
19. Answer: B. Chapter 21 , Objective 19: Concerning Cora Nari: She had a heart attack. Why was nasal oxygen administered? Why was her blood pressure lowered? What might have been the effect on ATP production if nitroprusside had been continued for several days? Back to question 19.
20. Answer: C. Chapter 21 , Objectives 20: Concerning Cora Nari: What is TPA and how does it dissolve blood clots? Back to question 20.
21. Answer: C. Chapter 21 , Objectives 21: Concerning Cora Nari: How did the change in the ratio of ATP to ADP and AMP affect anaerobic glycolysis? How did this affect the pH? Back to question 21.
22. Answer: E. Chapter 21 , Objective 22: Concerning X.S.Teefore, Explain how the affect of excess thyroid hormone on oxidative phosphorylation could explain increased appetite and sweating? Back to question 22.