Full Test Bank Energy and metabolism Chapter 15

Test questions for Chapter 15

Energy and metabolism

1. Which of the following statements describes a necessary role of glucose in the body?
   1. Glucose supplies energy to the brain.
   2. Proteins are composed of glucose.
   3. Fat stores are composed of glucose.
   4. Glucose is the only source of energy for the entire body.
   5. All of the above are true.
2. Which of the following biomolecules provides fuel for the brain?
   1. proteins
   2. steroids
   3. glucose
   4. triglycerides
   5. Any biomolecule can provide fuel for the brain.
3. Which of the following statements best describes why proteins are metabolized when calories are severely reduced?
   1. Actually, fats are metabolized during a starvation diet, not proteins.
   2. Proteins have the highest energy content per gram of any of the biomolecules.
   3. Proteins contain amino acids, which fuel the brain.
   4. Glycogen is a type of protein.
   5. There is a metabolic pathway in which glucose can be made from protein.
4. Which of the following statements does NOT describe the safest and healthiest way for a person to lose weight?
   1. A person should drastically reduce their caloric intake.
   2. A person should eat a moderate intake of calories.
   3. A person should include exercise in their daily routine.
   4. A person should eat nutritious foods.
   5. A person should maintain steady blood glucose levels.
5. Why is the metabolism of fat sometimes called “burning fat”?
   1. because the fat is heated
   2. because exercise is a painful activity
   3. because the fat is oxidized
   4. because exercise makes a person sweat and feel hot
   5. because the fat melts
6. Fats, proteins and carbohydrates are all broken down into __________, the central molecule of metabolism.
7. glucose
8. carbon dioxide
9. acetyl coenzyme A
10. ATP
11. pyruvate
12. Which of the following pathways directly produces acetyl CoA?
13. hydrolysis of proteins
14. hydrolysis of a polysaccharide
15. glycolysis
16. β-oxidation
17. All of the above directly produce acetyl CoA.
18. Catabolism is often called
19. oxidative phosphorylation.
20. cellular respiration.
21. anabolism.
22. oxidation-reduction.
23. the citric acid cycle.
24. Which of the following choices is NOT a function of cellular respiration?
    1. It converts food and oxygen to CO₂ and water.
    2. It extracts energy from food.
    3. It stores energy in the form of ATP.
    4. It builds proteins and synthesizes DNA.
    5. It reduces coenzymes NAD⁺ and FAD.
25. Which statement best summarizes the first stage of catabolism?
    1. Biomolecules are condensed in the first step.
    2. Biomolecules are hydrolysed in the first step.
    3. Biomolecules are reduced in the first step.
    4. Biomolecules are hydrated in the first step.
    5. All of the above occur in the first step of metabolism.
26. Protein, fat, and carbohydrate catabolism all share some key steps. Which of the following statements describes a part of catabolism that these biomolecules have in common?
27. These biomolecules undergo hydrolysis.
28. These biomolecules are broken down and then react to become acetyl CoA.
29. Acetyl CoA from these biomolecules enters the citric acid cycle.
30. The carbons in these biomolecules are eventually converted into CO₂ and coenzyme A.
31. Proteins, fats, and carbohydrates share all of these catabolic steps.
32. Whether a sugar starts out as a fructose, galactose, or glucose, it must undergo enzyme-catalyzed reactions in order to become a single type of monosaccharide so that it can go through the second stage of catabolism, glycolysis. Which monosaccharide must all of these sugars become?
33. fructose
34. galactose
35. mannose
36. talose
37. glucose
38. What is the first step of the metabolism of carbohydrates?
39. In the mouth, amylase hydrolyses starch into glucose, maltose, and dextrins.
40. In the stomach, amylase hydrolyses starch into glucose, maltose, and dextrins.
41. Glucose enters cells.
42. A phosphoryl group is transferred.
43. A glucose molecule is split into two pyruvates.
44. Under what circumstances are amino acids metabolized?
    1. They are metabolized during starvation.
    2. All dietary amino acids are metabolized.
    3. Essential amino acids are always metabolized.
    4. Proteins are not hydrolyzed into proteins under any circumstance.
    5. They are metabolized under anaerobic conditions.
45. What is the product of hydrolysis of a triglyceride in the first step of catabolism?
    1. one molecule of glycerol and three fatty acid molecules
    2. one molecule of glycerol and one fatty acid
    3. three glucose molecules
    4. glucose, fatty acids, and glycerol
    5. Triglycerides do not undergo hydrolysis during catabolism.
46. The ATP synthesized during catabolic processes is used to provide energy for ____ processes in the cell.
47. oxidative
48. anabolic
49. slow
50. unusual
51. spontaneous
52. Which of the following changes is NOT spontaneous?
53. water flowing downhill
54. two like charges attracting each other
55. a skydiver falling toward the earth
56. salt dissolving in water
57. the hydrolysis of ATP
58. Which of the following characteristics do spontaneous processes share?
59. They release heat.
60. They must be heated to occur.
61. They increase in order.
62. They can drive nonspontaneous processes.
63. They must be driven by other processes.
64. Which of the following statements about spontaneous reactions is NOT true?
65. If a reaction is spontaneous, the reverse reaction is nonspontaneous.
66. All spontaneous reactions occur quickly.
67. Spontaneous reactions occur without input of energy.
68. Spontaneous reactions have a negative energy value.
69. Spontaneous reactions can do work.
70. The following reactions are several steps in the conversion of acetyl coenzyme A to carbon dioxide. Which of the reactions is NOT spontaneous?

1. II only
2. IV only
3. III only
4. III and IV
5. I, III, and IV
6. Which of the following statements bests describes how nonspontaneous reactions occur in the body?
7. Reactions that are not spontaneous do not occur in the body.
8. Enzymes make these reactions occur at a reasonable rate.
9. The heat of the body drives these reactions.
10. They are coupled to spontaneous reactions.
11. Nonspontaneous reactions occur just like spontaneous ones do, without any input of energy.
12. Which of the following terms describes the role of ATP in this reaction?

C₃H₈O₃ C₃H₇O₃PO₃

1. The hydrolysis of ATP is inhibiting this reaction.
2. The hydrolysis of ATP is a catalyst for this reaction.
3. The hydrolysis of ATP is regulating this reaction.
4. The hydrolysis of ATP is coupled to this reaction.
5. All of the above
6. The first step of glycolysis is phosphorylating glucose to make glucose 6-phosphate as shown below. Which of the following statements about this reaction is TRUE?

Glucose + P_i → glucose 6-phosphate + H₂O ΔG = + 3.3 kcal/mol

1. This reaction releases energy.
2. This reaction is spontaneous.
3. This reaction cannot occur in the body.
4. This reaction must be coupled to another reaction to occur.
5. An enzyme is required to provide the energy for this reaction.
6. During fatty acid oxidation, a fatty acid must react with coenzyme A to become a fatty acyl-CoA, as shown below.

Fatty acid + CoA → Fatty acyl – CoA ΔG = + 7.0 kcal/mol

In the body, the reaction above is coupled to the hydrolysis of two phosphate groups from ATP as shown below:

ATP → AMP + 2 P_i ΔG = −15.7 kcal/mol

Which of the following chemical equations correctly shows these two reactions coupled together?

1. During fatty acid oxidation, a fatty acid must react with coenzyme A to become a fatty acyl-CoA, as shown below.

Fatty acid + CoA → Fatty acyl – CoA ΔG = + 7.0 kcal/mol

In the body, the reaction above is coupled to the hydrolysis of two phosphate groups from ATP as shown below:

ATP → AMP + 2 P_i ΔG = −15.7 kcal/mol

Which of the following equations is the correct calculation of the overall free energy of the coupled reaction?

1. ΔG_overall = 7.0 kcal/mol + 15.7 kcal/mol
2. ΔG_overall = 7.0 kcal/mol − 15.7 kcal/mol
3. ΔG_overall = 15.7 kcal/mol + 7.0 kcal/mol
4. ΔG_overall = 7 kcal/mol × 15.7 kcal/mol
5. ΔG_overall = 7 kcal/mol × −15.7 kcal/mol
6. The structure below is acetyl coenzyme A. Select the choice in which each part of acetyl coenzyme A is correctly labeled.

1. What is the purpose of coenzyme A in metabolism?
2. Coenzyme A delivers ADP so that it can be phosphorylated to become ATP.
3. Coenzyme A delivers ATP so that it can be dephosphorylated to become ADP.
4. Coenzyme A provides the energy for catabolism to occur.
5. Coenzyme A transfers electrons to where they need to go.
6. Coenzyme A transfers acyl groups.
7. Which of the following molecules could be transferred by coenzyme A?

1. None of these could be transferred by Coenzyme A.
2. Only I could be transferred.
3. I and II could be transferred by Coenzyme A.
4. Only III could be transferred.
5. All of these could be transferred by Coenzyme A.
6. Which of the following molecules is an acetyl group?

1. When acetyl coenzyme A is hydrolyzed during the citric acid cycle, which bond in the molecule is broken?

1. The partial structures of the coenzymes NADH and NAD⁺ are shown below. What type of reaction is this?

NADH NAD⁺

a. oxidation

b. reduction

c. acid-base

d. hydrolysis

e. condensation

1. Which bond is broken when ATP is hydrolyzed to ADP?

a. a b. b c. c d. d e. e

1. Which of the following choices correctly label each type of bond in the following molecule of ATP?

1. All are phosphate ester bonds.
2. All are phosphoanhydride bonds.
3. Both a and b are phosphoanhydride bonds and c is a phosphate ester bond.
4. Both a and b are phosphate ester bonds and c is a phosphoanhydride bonds.
5. Both a and c are phosphate ester bonds and b is a phosphoanhydride bonds.
6. What are the products of ATP hydrolysis?
7. ADP and P_i­
8. AMP and P_i
9. ADP and water
10. AMP and water
11. ADP, AMP, P_i, and water
12. During ATP hydrolysis, to what molecule is a phosphoryl group transferred?
13. another ATP
14. ADP
15. AMP
16. water
17. P_i
18. During glucose metabolism, the following reaction occurs. What is this reaction called?

1. phosphoryl group transfer reaction
2. hydrolysis
3. hydration
4. dehydration
5. oxidation
6. Which bond in ATP is referred to as a “high-energy bond”?
7. a C–H bond
8. a C–P bond
9. a C–O bond
10. a P–O bond
11. a P=O bond
12. Energy is only released during a reaction when a bond is formed, never when it is broken. Which bond is formed during ATP hydrolysis, releasing energy?
13. a C–H bond
14. a C–P bond
15. a H–O bond
16. a P–O bond
17. a P=O bond
18. A “high-energy bond” is a bond that
19. releases energy when it is broken.
20. is very strong.
21. is very stable.
22. is weak.
23. requires energy to form.
24. The following reaction is a key step in the metabolism of glucose. Which of the following molecules is formed as a result of this reaction?

1. ADP
2. H⁺
3. ATP
4. H₂O
5. P_i
6. Which of the following pathways results in pyruvate?
7. hydrolysis
8. glycolysis
9. gluconeogenesis
10. the citric acid cycle
11. All of these pathways produce pyruvate.
12. Where in the cell does glycolysis occur?
13. in the mitochondria
14. in endoplasmic reticulum
15. in the golgi complex
16. in the cytoplasm
17. in the vacuoles
18. Which of the following statements about glycolysis is NOT true?
    1. Glycolysis is the only energy producing metabolic pathway in the brain.
    2. Glycolysis requires oxygen.
    3. Anaerobic microorganisms use glycolysis for energy production.
    4. Glycolysis is an important biochemical pathway in botulism.
    5. Glycolysis produces pyruvate from glucose.

1. As a monosaccharide goes through glycolysis, it must stay within the cell. How are the starting monosaccharide and all of the intermediates of glycolysis kept within the cell during glycolysis?
2. Nothing needs to be done to them; the molecules just stay in the cell.
3. The hydroxyl groups lose their protons and become negatively charged.
4. The molecules are phosphorylated.
5. The molecules attach to enzymes in the cytoplasm.
6. All of the above can occur.
7. Which of the following is NOT a purpose of the glycolysis pathway?
8. It is a way to extract energy from glucose without the use of oxygen.
9. It is a way to extract and store energy as ATP.
10. It is a way to form pyruvate.
11. It is a way to make NADH.
12. It is a way to make FAD⁺.
13. Which of the choices below best describes the purpose of the following step of glycolysis?

a. In this step, the molecule is phosphorylated to keep it in the cell.

b. In this step, the molecule is split into two, both of which will become pyruvate.

c. In this step, NADH is made.

d. In this step, energy is stored as ATP.

e. In this step, pyruvate is made.

1. Which of the choices below best describes the purpose of the following step of glycolysis?

a. In this step, the molecule is phosphorylated to keep it in the cell.

b. In this step, the molecule is split into two, both of which will become pyruvate.

c. In this step, NADH is made.

d. In this step, energy is stored as ATP.

e. In this step, pyruvate is made.

1. Which of the choices above below describes the purpose of the following step of glycolysis?

a. In this step, the molecule is phosphorylated to keep it in the cell.

b. In this step, the molecule is split into two, both of which will become pyruvate.

c. In this step, NADH is made.

d. In this step, energy is stored as ATP.

e. In this step, pyruvate is made.

1. Which of the choices below best describes the purpose of the following step of glycolysis?

a. In this step, the molecule is phosphorylated to keep it in the cell.

b. In this step, the molecule is split into two, both of which will become pyruvate.

c. In this step, energy is stored as ATP.

d. In this step, pyruvate is made.

e. In this step, both pyruvate and ATP are made.

1. What is the relationship between the following two intermediates in glycolysis?

1. They are identical.
2. They are conformers.
3. They are enantiomers.
4. They are constitutional isomers.
5. They are diastereomers.
6. One of the steps of glycolysis is given below. What type of reaction is this?

1. oxidation
2. hydration
3. hydrogenation
4. dehydration
5. phosphoryl transfer
6. The net result of glycolysis is an output of energy in the form of _______ from the catabolism of a single glucose molecule.
7. 2 ATPs
8. 2 NADHs
9. 4 ATPs
10. 2 ATPs and 2 NADHs
11. 4 ATPs and 2 NADHs
12. Which of the following statements about glycolysis is TRUE?
13. In every step of glycolysis, energy is stored as ATP.
14. A phosphate group is on every intermediate.
15. Glycolysis is an aerobic process.
16. Any sugar can be converted to pyruvate through glycolysis.
17. All of the above statements are true.
18. Which of the following statements best describes the purpose of oxygen in the oxidation of pyruvate to acetyl CoA?
19. The oxygen is released during the reaction.
20. The oxygen is required to react with pyruvate.
21. The oxygen makes HS-CoA more reactive.
22. The oxygen regenerates NAD+ from NADH.
23. The oxygen reacts with H⁺.
24. Which of the following statements describe what can happen to pyruvate after it is produced during glycolysis?
    • 1. Pyruvate immediately enters the citric acid cycle.
      2. It is oxidized.
      3. It is reduced.
25. I only
26. II only
27. III only
28. II and III
29. I and II
30. The fate of pyruvate depends on its environment. Which of the following choices correctly matches how pyruvate reacts, what molecule it becomes, and where it goes next?

1. Which of the following statements does NOT describe conditions under which lactic acid is formed?
2. Lactic acid is formed in aerobic conditions.
3. Lactic acid is formed when oxygen is depleted.
4. Lactic acid is formed during vigorous exercise.
5. Lactic acid is produced by the bacteria that cause tooth decay.
6. Actually, all of these are true.
7. Lactic acid is turned back into pyruvate in the liver. Which statement best describes the body’s purpose in making lactic acid from pyruvate in the first place?
8. To cause “the burn” during strenuous exercise.
9. To raise the pH of the immediate environment.
10. To produce NAD+ for use in glycolysis.
11. To produce FADH₂ for use in glycolysis.
12. To regenerate ADP.
13. Which of the following processes does NOT occur during the citric acid cycle?
14. ADP is phosphorylated to make ATP.
15. NAD⁺ is reduced to NADH.
16. FAD is reduced to FADH₂.
17. GDP is phosphorylated to make GTP.
18. CO₂ is released.
19. Which of the following choices is the key outcome of the citric acid cycle?
20. Oxygen is consumed.
21. Carbon dioxide is released.
22. Biomolecules are catabolized.
23. FAD and NAD⁺ are reduced.
24. ADP is phosphorylated.
25. What is the last stage of metabolism for glucose, fatty acids and some amino acids?
    1. glycolysis
    2. β-oxidation
    3. pyruvate catabolism
    4. hydrolysis
    5. the citric acid cycle
26. The citric acid cycle is a unique metabolic pathway because it is cyclic. Which statement best describes how it is cyclic?
27. It is cyclic because oxaloacetate is regenerated.
28. It is cyclic because FAD and NAD⁺ are reduced.
29. It is cyclic because CO₂ is regenerated.
30. It is cyclic because it is linked with oxidative phosphorylation.
31. All of the above are reasons that the citric acid cycle is cyclic.
32. Which of the following choices is NOT a common name for the citric acid cycle?
33. CAC
34. TCA cycle
35. Krebs cycle
36. tricarboxylic acid cycle
37. All of these are common names of the citric acid cycle.
38. Every acetyl CoA molecule that goes through the citric acid cycle provides enough energy to phosphorylate ____ ADP molecules to ATP.
    1. 10
    2. 5
    3. 1
    4. 100
    5. 0
39. In the electron-transport chain, one NADH molecule supplies the energy to phosphorylate ___ ADP molecules and one FADH₂ supplies the energy to phosphorylate ___ ADP molecules.
40. 1; 1
41. 2; 2
42. 3; 3
43. 2; 3
44. 2.5; 1.5
45. The citric acid cycle has a unique circular appearance when written due to the regeneration of oxaloacetate. Which of the following molecules is oxaloacetate?

a. b. c. d. e.

1. Two molecules of carbon dioxide are released for every turn of the citric acid cycle. What happens to those molecules of carbon dioxide?
2. They are used in anabolic processes.
3. They stay within the citric acid cycle, contributing to the cyclic nature of the pathway.
4. They are exhaled.
5. They are excreted in urine.
6. They undergo oxidative phosphorylation.
7. Which of the following statements best describes what is illustrated in this diagram?

1. This diagram illustrates the carbon balance of the citric acid cycle.
2. This diagram illustrates the electron balance of the citric acid cycle.
3. This diagram illustrates the oxygen balance of the citric acid cycle.
4. This diagram illustrates the hydrogen balance of the citric acid cycle.
5. All of the above are illustrated in this diagram.
6. According to the diagram below, what happens to the four atoms that begin the citric acid cycle in oxaloacetate?

1. All four atoms continue around the cycle over and over again.
2. Two of the atoms continue around the cycle a second time and two atoms are released from the cycle.
3. One of the atoms continues around the cycle a second time and three atoms are released from the cycle.
4. Three of the atoms continue around the cycle a second time and one atom is released from the cycle.
5. All four atoms are released from the cycle.
6. What is the identity of I in the following diagram of the citric acid cycle?

1. acetate
2. GTP
3. NADH
4. FADH₂
5. carbon dioxide
6. The following is step 8 of the citric acid cycle. During this step, NAD⁺ is ________ while L-malate is ________.

1. phosphorylated; isomerized
2. isomerized; dehydrated
3. oxidized; reduced
4. reduced; oxidized
5. hydrated; dehydrated
6. L-malate is an intermediate in the citric acid cycle. What does the L imply about L-malate?
7. L-malate is highly reactive.
8. L-malate is non-reducible.
9. L-malate is chiral.
10. L-malate is an amino acid.
11. L-malate is a lipid.
12. The following is step 3 of the citric acid cycle. Isocitrate is converted into α-ketoglutarate by a(n) _______ reaction followed by _______.

1. oxidation-reduction; phosphorylation
2. phosphorylation; oxidation-reduction
3. isomerization; dehydration
4. oxidation-reduction; decarboxylation
5. hydration; decarboxylation
6. The following is step 3 of the citric acid cycle. During this step, NAD⁺ is ________, while isocitrate is ________.

1. phosphorylated; isomerized
2. isomerized; dehydrated
3. oxidized; reduced
4. reduced; oxidized
5. hydrated; dehydrated
6. The following is step 3 of the citric acid cycle. What is the functional group transformation that occurs in the first part of this step?

1. A ketone and an alcohol change positions.
2. An alcohol becomes a ketone.
3. The –COO^– is transformed.
4. The alcohol becomes an aldehyde.
5. A carbon-carbon double bond is added.

1. The following is step 3 of the citric acid cycle. What is the identity of the molecule represented by I?

1. acetate
2. GTP
3. NADH
4. FADH₂
5. carbon dioxide
6. What occurs during the process known as oxidative phosphorylation?
7. NADH produced during the citric acid cycle is oxidized.
8. FADH₂ produced during the citric acid cycle is oxidized.
9. ADP is phosphorylated to make ATP.
10. Oxygen is reduced to water.
11. All of the above processes occur.
12. Where in the cell does oxidative phosphorylation occur?
13. everywhere
14. in the ribosomes
15. in the mitochondria
16. in the cytoplasm
17. in the nucleus
18. Which of the following processes does NOT occur in the mitochondria?
19. β-oxidation
20. citric acid cycle
21. oxidative phosphorylation
22. glycolysis
23. All of these occur in the mitochondria.
24. Most enzymes involved in the citric acid cycle are found in the ________ of the mitochondria.
25. inner membrane
26. outer membrane
27. intermembrane space
28. matrix
29. The citric acid cycle does not occur in the mitochondria.
30. ATP-synthase, an enzyme that catalyzes the phosphorylation of ADP to ATP, is found here.
31. inner membrane
32. outer membrane
33. intermembrane space
34. matrix
35. the inner membrane and the matrix
36. Which parts of the mitochondria are lipids?
37. inner membrane
38. outer membrane
39. intermembrane space
40. matrix
41. Both membranes are lipids.
42. Which of the following statements about the role of oxygen in the electron-transport chain is NOT true?
43. Oxygen is the ultimate receptor of electrons.
44. Oxygen is reduced to water during oxidative phosphorylation.
45. We inhale oxygen so that it can be used to accept electrons.
46. Catabolism is called cellular respiration because it uses oxygen.
47. All of the above are true.
48. Which of the following statements best describes the electron-transport chain?
49. It is a series of protein complexes that transfer electrons from NADH and FADH₂ to oxygen.
50. It is another name for the citric acid cycle.
51. It is the same thing as catabolism.
52. It is cyclic, where the same oxygens are used over and over to transport electrons.
53. All of the above are true.
54. Which of the following proteins is mobile?
55. Complex I
56. Complex II
57. Complex III
58. Complex IV
59. cytochrome C
60. What is the role of coenzyme Q and cytochrome C in the electron-transport chain?
61. They pump protons from the matrix to the intermembrane space.
62. They pump protons from the intermembrane space to the matrix.
63. The carry coenzymes from one protein complex to the next protein complex.
64. They carry electrons from one protein complex to the next protein complex.
65. They carry small ions from one protein complex to the next protein complex.
66. What is the primary purpose of the flow of electrons through the protein complexes in the inner mitochondrial membrane?
67. To reduce oxygen.
68. To oxidize NADH and FADH₂.
69. To supply energy for the proton pump.
70. To reduce enzymes involved in catabolism.
71. To phosphorylate ADP.
72. The following figure illustrates a proton gradient. In this figure, protons are indicated by small circles. Which part of the figure has the lowest pH?

I II

1. part I because it has a lower concentration of protons
2. part II because it has a lower concentration of protons
3. part I because it has a higher concentration of protons
4. part II because it has a higher concentration of protons
5. They both have the same pH because pH has nothing to do with protons.
6. A difference in proton concentration between adjacent regions is known as a
7. pH difference.
8. proton concentration difference.
9. proton gradient.
10. PCAR.
11. mitochondrion.
12. The figure below illustrates protons (the circles) separated by a membrane permeable to the protons and water. What will happen to the protons as time passes and the system equilibrates?

I II

permeable membrane

1. The protons will neutralize.
2. All of the protons will move from compartment I to compartment II.
3. All of the protons will move from compartment II to compartment I.
4. The concentration of the protons in compartments I and II will become equal.
5. Nothing will happen.
6. The potential energy stored in the unequal distribution of protons is called
7. the proton pump.
8. oxidation-reduction.
9. pH.
10. the electron-transport chain.
11. the proton-motive force.
12. Even though there are more protons in the intermembrane space of the mitochondria, protons do not diffuse from there into the matrix. Why not?
13. They do not diffuse because the inner mitochondrial membrane is not permeable to them.
14. They do not diffuse because that would require energy.
15. They do not diffuse because only water diffuses, not protons.
16. They do not diffuse because they are not charged.
17. Actually, they do diffuse.
18. By which of the following chemical reactions does the electron-transport chain occur?
19. protonation-deprotonation
20. hydration-dehydration
21. oxidation-reduction
22. isomerization
23. phosphorylation-dephosphorylation
24. What is the general order in which electrons pass through the electron-transport chain?
25. from lowest electron affinity to highest electron affinity
26. from highest electron affinity to lowest electron affinity
27. from most reactive to least reactive
28. form strongest acid to weakest acid
29. from most mobile to least mobile
30. What is the fate of oxygen in the electron transport chain?
    1. It is oxidized.
    2. It becomes carbon dioxide.
    3. It is reduced to water.
    4. It is added to an alkene.
    5. Any of these can occur.
31. The following diagrams illustrate the two aqueous spaces and the inner membrane of the mitochondrial. In which diagram is the relative concentration of protons such that oxidative phosphorylation could occur if ATP synthase were present?

1. What is the role of ATP synthase in the synthesis of ATP?
2. ATP synthase harvests the energy for the synthesis.
3. ATP synthase catalyzes the phosphorylation of ADP reaction.
4. ATP synthase captures APD and P_i.
5. ATP synthase allows protons to flow into the matrix through its proton channel.
6. All of the above are roles of ATP synthase.
7. Where does ATP synthase get the energy required to drive phosphorylation of ADP?
8. the potential energy of the proton motive force
9. from the reduction of NAD⁺
10. from the hydrolysis of ATP
11. from the reduction of oxygen
12. ATP synthase does not require energy.
13. Where does ATP synthase get the energy required to drive phosphorylation of ADP?
14. from the flow of protons from the intermembrane space to the matrix through the inner membrane
15. from the flow of protons from the matrix to the intermembrane space through the inner membrane
16. from the flow of protons from the intermembrane space to the matrix through the enzyme
17. from the flow of protons from the matrix to the intermembrane space through the enzyme
18. from ATP
19. What is the name of the force that drives the phosphorylation of ADP?
20. gravity
21. osmotic pressure
22. weak
23. electric
24. proton-motive
25. When ATP synthase catalyzes the synthesis of ATP, protons are shunted through it. Which of the following diagrams best illustrates this process? Note that the circles represent protons and the arrows through the enzyme represent the direction of proton flow.

1. Overall, how much ATP is produced when one molecule of glucose is oxidized to 6 molecules of carbon dioxide through glycolysis, aerobic oxidation of pyruvate, the citric acid cycle, and oxidative phosphorylation?
   1. none
   2. 10 ATP
   3. 32 ATP
   4. 99 ATP
   5. The number of ATP is highly variable.
2. Which of the following choices illustrates the general pathway by which fats are catabolized?
3. reduction to acetyl CoA → citric acid cycle
4. oxidation to acetyl CoA → citric acid cycle
5. hydrolysis → reduction to acetyl CoA → citric acid cycle
6. hydrolysis → oxidation to acetyl CoA → citric acid cycle
7. hydrolysis → citric acid cycle
8. Where in the cell does β-oxidation take place?
9. the mitochondria
10. the cell membrane
11. the cytoplasm
12. the nucleus
13. everywhere
14. What is produced by β-oxidation?
15. acetyl CoA only
16. acetyl CoA and ATP
17. acetyl CoA, NADH, and FADH­₂
18. ATP only
19. ATP, NADH, and FADH₂
20. How is a fatty acid activated before it goes through β-oxidation?
21. It forms a thioester with Coenzyme A.
22. It is hydrolyzed.
23. It is deprotonated.
24. It is reduced.
25. Actually, it’s not activated.
26. How many carbons are removed from a fatty acid each time the fatty acid goes through β-oxidation?
27. 0
28. 1
29. 2
30. 3
31. 4

.

1. The first step of β-oxidation is shown below. What type of reaction is this?

1. oxidation
2. reduction
3. hydration
4. hydrolysis
5. hydrogenation
6. The second step of β-oxidation is shown below. What type of reaction is this?

1. oxidation
2. reduction
3. hydration
4. hydrolysis
5. hydrogenation
6. The third step of β-oxidation is shown below. What type of reaction is this?

1. oxidation
2. reduction
3. hydration
4. hydrolysis
5. hydrogenation
6. How many times will a fatty acid with 20 carbons go through β-oxidation?
7. 20
8. 19
9. 18
10. 10
11. 9
12. In which of the following choices is the number of ATPs produced as a result of the catabolism of 1 myristic acid (14 carbons) molecule correctly calculated?

1. Why is fatty acid catabolism called β-oxidation?
2. because half of the reactions involve oxidation of the third carbon atom in the fatty acid chain
3. because half of the reactions involve oxidation of the second carbon atom in the fatty acid chain
4. because half of the reactions involve oxidation of the first carbon atom in the fatty acid chain
5. because it is the second biochemical pathway in fatty acid catabolism
6. because it is the penultimate pathway in fatty acid catabolism
7. Generally, how do compounds such as rotenone and cyanide inhibit the electron transport chain?
   1. They block electron transfer downstream from the inhibitor bound enzyme.
   2. They absorb electrons.
   3. They are acidic.
   4. They inhibit the production of proteins involved in the electron transfer chain.
   5. They increase the rate of electron transfer.
8. Which part of the electron transport chain does cyanide inhibit?
   1. all of it
   2. Complex I
   3. Complex I and III
   4. Complex II
   5. the reduction of oxygen
9. Which of the following is NOT a symptom of cyanide poisoning?
   1. stroke
   2. headache
   3. lethargy
   4. respiratory arrest
   5. convulsions
10. Cyanide alters the normal relative concentration of protons in the intermembrane space and the matrix of the mitochondria. What is the effect of this change in concentration?
11. The electron-transport chain will run out of control.
12. NADH cannot be oxidized.
13. FADH₂ cannot be oxidized.
14. ATP cannot be synthesized.
15. All of the above are true.