Deck 23: Metabolism and Energy Production

Question 1

The citric acid cycle is used in the oxidation of

A) glucose only.
B) glucose and fatty acids only.
C) fatty acids only.
D) glucose, fatty acids, and proteins.
E) proteins only.

Answer 1

glucose, fatty acids, and proteins.

Question 2

Which of the following compounds in the citric acid cycle undergoes oxidative decarboxylation?

A) citrate
B) isocitrate
C) succinate
D) fumarate
E) succinyl CoA

Answer 2

isocitrate

Question 3

FAD is a coenzyme which usually participates in

A) oxidation of alcohols to aldehydes.
B) formation of carbon-carbon double bonds.
C) decarboxylation reactions.
D) phosphorylation reactions.
E) β-oxidation reactions.

Answer 3

formation of carbon-carbon double bonds.

Question 4

Which coenzyme is the electron acceptor in the following reaction?

A) FAD
B) NAD+
C) FMN
D) NADH
E) FADH₂

Question 5

The transformation of citrate to isocitrate in the citric acid cycle requires two __________ reactions.

A) oxidation
B) reduction
C) hydrolysis
D) decarboxylation
E) dehydration-hydration

Question 6

Another name for the citric acid cycle is

A) the Krebs cycle.
B) gluconeogenesis.
C) glucose hydrolysis.
D) oxidative phosphorylation.
E) the chemiosmotic pump.

Question 7

Most of the energy released in the citric acid cycle is used to produce

A) glucose.
B) acetyl CoA.
C) NADH and FADH₂.
D) carbon dioxide and water.
E) citric acid.

Question 8

In the first reaction of the citric acid cycle

A) glucose becomes pyruvate.
B) ATP is produced.
C) NADH is produced.
D) acetyl CoA reacts with oxaloacetate to give citrate.
E) pyruvate becomes CO₂ and H₂O.

Question 9

During the first reaction in the citric acid cycle,

A) free CoA is released.
B) acetyl CoA is made.
C) a decarboxylation occurs.
D) a decomposition occurs.
E) ATP is synthesized.

Question 10

NAD+ participates in reactions that produce

A) a CH₂ group.
B) a C=O bond.
C) phosphorylation.
D) ADP from ATP.
E) a C-C bond.

Question 11

The citric acid cycle operates only under aerobic conditions because

A) oxygen is a reactant in the citric acid cycle.
B) oxygen is a product of the citric acid cycle.
C) CO₂ is a product of the citric acid cycle.
D) the NADH and FADH₂ produced by the citric acid cycle can only be reoxidized by the electron transport chain.
E) the NAD⁺ and FAD produced by the citric acid cycle can only be reduced by the electron transport chain.

Question 12

Which of the following is the net reaction for one turn of the citric acid cycle?

A) Acetyl-S-CoA + 3 NAD+ + FAD + GDP + Pi + 2H₂O → 2 CO₂ + 3 NADH + 3 H+ + FADH₂ + HS-CoA + GTP
B) Pyruvate + 3 NAD+ + FAD + GDP + Pi + 2H₂O → 3 CO₂ + 3 NADH + 3 H+ + FADH₂ + GTP
C) Acetyl-S-CoA + NAD+ + FAD + GDP + Pi → 2 CO₂ + NADH + H+ + FADH₂ + HS-CoA + GTP
D) Glucose + 2 NAD+ + 2GDP + 2 Pi + 2H₂O → 2Pyruvate + 2 NADH + 2 H+ + GTP
E) Glucose + 2GDP + 2Pi → 2Lactate + 2GTP

Question 13

Which coenzyme is the electron acceptor in the following reaction?

A) FAD
B) NAD+
C) FMN
D) NADH
E) FADH₂

Question 14

What electron acceptor(s) is(are) used in the citric acid cycle?

A) FAD only
B) NAD+ only
C) NADH + FADH₂ + CoASH
D) FMN
E) NAD+ + FAD

Question 15

Which of the three major stages of metabolism includes the citric acid cycle?

A) Stage one
B) Stage two
C) Stage three

Question 16

Another name for the citric acid cycle is

A) electron transport.
B) glycolysis.
C) the tricarboxylic acid (TCA) cycle.
D) glucolysis.
E) the transamination pathway.

Question 17

In order to enter the citric acid cycle, pyruvate is first converted to

A) ate.
B) acetaldehyde.
C) citrate.
D) acetyl CoA.
E) ethanol.

Question 18

The citric acid cycle takes place in the

A) mitochondria.
B) cytosol.
C) cytoplasm.
D) Golgi apparatus.
E) endoplasmic reticulum.

Question 19

When oxygen is in plentiful supply in the cell, pyruvate is converted to

A) CoA.
B) acetyl CoA.
C) glucose.
D) lactate.
E) fructose.

Question 20

When combined with electron transport, one turn of the citric acid cycle produces __________ ATP.

A) 24
B) 12
C) 11
D) 14
E) 2

Question 21

The citric acid cycle step that removes the first CO₂ molecule is a(n)

A) oxidative decarboxylation.
B) reduction.
C) carbonylation.
D) hydrolysis.
E) combination.

Question 22

Under anaerobic conditions, there is a net production of __________ ATP during glycolysis.

A) zero
B) two
C) four
D) six
E) eight

Question 23

In the chemiosmotic model, protons circulate through a protein complex called

A) iron-sulfur clusters.
B) FMA.
C) CoA.
D) CoQ.
E) ATP synthase.

Question 24

In electron transport, the oxidized product from the reaction of FMN + NADH + H+ is

A) CoQ.
B) FMNH₂.
C) FADH.
D) FAD.
E) NAD+.

Question 25

Step 5 of the citric acid cycle is the hydrolysis of succinyl CoA. In this reaction

A) the energy released is used to make GTP.
B) the energy released is used to make ATP.
C) carbon dioxide is released.
D) α-ketoglutarate is released.
E) the enzyme aconitase is needed.

Question 26

In the chemiosmotic model of oxidative phosphorylation, ATP is synthesized as

A) OH- flows through ATP synthase.
B) electrons flow through ATP synthase.
C) Ca2+ flows through ATP synthase.
D) H+ flows through ATP synthase.
E) Na+ flows through ATP synthase.

Question 27

The electron carrier __________ provides two ATP via electron transport.

A) FADH₂
B) NADH
C) NADPH
D) CoASH
E) FNMH₂

Question 28

In electron transport, the three protein complexes (I, III, and IV)

A) act as proton pumps, which generate a proton gradient.
B) transfer electrons from NAD+ to O₂.
C) transfer electrons from FAD to O₂.
D) act as electron pumps, which generate an electron gradient.
E) act as Ca2+ pumps, which generate a Ca2+ gradient.

Question 29

In the dehydration of succinate to fumarate in the citric acid cycle, the coenzyme used is

A) CoA.
B) acetyl CoA.
C) NAD+.
D) NADH.
E) FAD.

Question 30

The GTP formed in step 5 of the citric acid cycle is used to make

A) carbon dioxide.
B) oxygen.
C) water.
D) CoA.
E) ATP.

Question 31

In the hydrolysis of succinyl CoA in step 5 of the citric acid cycle, CoA is released as

A) CoA-SH.
B) CoA-OH.
C) CoA-O-.
D) CoA- S-
E) CoA- COO-.

Question 32

The last step in the citric acid cycle converts malate to

A) citrate.
B) isocitrate.
C) succinate.
D) fumarate.
E) oxaloacetate.

Question 33

The process which requires oxygen to produce carbon dioxide and water is called

A) fermentation.
B) reduction.
C) decomposition.
D) oxidation.
E) respiration.

Question 34

Cyanide ion and carbon monoxide inhibit

A) cytochrome c oxidase.
B) ATP production.
C) antibiotic activity.
D) CoQ formation.
E) CoA formation.

Question 35

The components of the electron transport chain do NOT include

A) oxygen (O₂).
B) cytochromes.
C) FMN.
D) CoQ.
E) acetyl CoA.

Question 36

In electron transport, the synthesis of ATP from ADP + Pi is called

A) glycolysis.
B) fermentation.
C) oxidative phosphorylation.
D) isomerization.
E) hydrolysis.

Question 37

One method of regulation of the citric acid cycle is

A) allosteric control.
B) osmosis.
C) temperature control.
D) carbon dioxide production.
E) water concentration.

Question 38

In the third major step of the citric acid cycle, NAD+ is converted to

A) NAS-.
B) NAD2+.
C) NADH₂
D) NAD.
E) NADH.

Question 39

In step 7 of the citric acid cycle, fumarate is converted to malate by a __________ reaction.

A) hydrolysis
B) dehydrogenation
C) hydrogenation
D) hydration
E) dehydration

Question 40

Which of the following metabolic pathways can occur in the absence of oxygen?

A) electron transport
B) oxidative phosphorylation
C) citric acid cycle
D) glycolysis
E) β-oxidation

Question 41

In this figure depicting the Stages of Metabolism taken from your text, identify the metabolic substance numbered.
substance 8

Question 42

Overall, one turn of the citric acid cycle produces

A) three CO₂ molecules.
B) three NADH molecules.
C) two FADH₂ molecules.
D) 6 ATP.
E) 2 GTP.

Question 43

In this figure depicting the Stages of Metabolism taken from your text, identify the metabolic substance numbered.
substance 6

Question 44

In this figure depicting the Stages of Metabolism taken from your text, identify the metabolic substance numbered.
substance 1

Question 45

Which is the best choice for the box labeled "Answer" in the illustration below?

A) oxidized carrier B
B) carbon dioxide
C) OH-
D) reduced carrier BH₂
E) energy

Question 46

In this figure depicting the Stages of Metabolism taken from your text, identify the metabolic substance numbered.
substance 7

Question 47

In this figure depicting the Stages of Metabolism taken from your text, identify the metabolic substance numbered.
substance 2

Question 48

What is the correct coefficient for ATP in the complete combustion of glucose? C6H12O6 + 6O₂ → 6CO₂ + _____ ATP + 6H₂O

A) 6
B) 12
C) 18
D) 24
E) 36

Question 49

The energy released during electron transport is used to produce

A) glucose.
B) citric acid.
C) carbon dioxide.
D) ATP.
E) NADH.

Question 50

In glycolysis, glucose produces 2 pyruvate ions and a total of __________ ATP molecules.

A) 2
B) 4
C) 6
D) 8
E) 12

Question 51

One example of an electron carrier in the respiratory chain is

A) ATP.
B) GTP.
C) coenzyme Q.
D) citrate.
E) water.

Question 52

Electron transport is also called

A) the citric acid cycle.
B) β-oxidation.
C) transamination.
D) the respiratory chain.
E) fermentation.

Question 53

The complete oxidation of glucose produces __________ ATP molecules.

A) 2
B) 8
C) 12
D) 24
E) 36

Question 54

In stage three of metabolism, the overall result is to release

A) glucose and water.
B) lactate and acetyl CoA.
C) lactate and glucose.
D) glycogen and water.
E) carbon dioxide and energy.

Question 55

In this figure depicting the Stages of Metabolism taken from your text, identify the metabolic substance numbered.
substance 5

Question 56

In this figure depicting the Stages of Metabolism taken from your text, identify the metabolic substance numbered.
substance 4

Question 57

In this figure depicting the Stages of Metabolism taken from your text, identify the metabolic substance numbered.
substance 3

Question 58

Which of the following is NOT a possible product of pyruvate under anaerobic conditions?

A) lactate
B) acetaldehyde
C) fumarate
D) ethanol
E) CO₂

Question 59

In electron transport, NADH and FADH₂ are used to provide

A) oxygen.
B) electrons and hydrogen ions.
C) carbon atoms.
D) water and carbon dioxide.
E) thiol groups.

Question 60

The compounds in the respiratory chain that remove hydrogen ions and electrons from NADH are classified as

A) oxidative transporters.
B) osmotic carriers.
C) electron carriers.
D) phosphorylators.
E) citrates.

Question 61

The conversion of ATP to ADP and inorganic phosphate produces 7.3 kcal/mole of energy.

Question 62

Indicate the amount of ATP produced when each of the following reactions occurs.
complete oxidation of glucose

A)6 ATP
B)2 ATP
C)36 ATP
D)12 ATP
E)3 ATP

Question 63

In this figure, depicting part 1 of the Citric Acid Cycle, taken from your text, identify the substances numbered.
substance 13

Question 64

In this figure, depicting part 1 of the Citric Acid Cycle, taken from your text, identify the substances numbered.
substance 15

Question 65

NAD+ acts as a hydrogen acceptor in metabolic reactions.

Question 66

In this figure, depicting part 1 of the Citric Acid Cycle, taken from your text, identify the substances numbered.
substance 17

Question 67

In reaction 4 of the citric acid cycle, α-ketoglutarase , a five-carbon keto acid, is decarboxylated.

Question 68

12 ATP are produced when glucose is oxidized to CO₂ and H₂O.

Question 69

Indicate the amount of ATP produced when each of the following reactions occurs.
glucose → 2 pyruvate under aerobic conditions

A)6 ATP
B)2 ATP
C)36 ATP
D)12 ATP
E)3 ATP

Question 70

In this figure, depicting part 1 of the Citric Acid Cycle, taken from your text, identify the substances numbered.
substance 18

Question 71

In this figure depicting the Stages of Metabolism taken from your text, identify the metabolic substance numbered.
process 10

Question 72

Indicate the amount of ATP produced when each of the following reactions occurs.
Acetyl CoA → 2CO₂

A)6 ATP
B)2 ATP
C)36 ATP
D)12 ATP
E)3 ATP

Question 73

In this figure, depicting part 1 of the Citric Acid Cycle, taken from your text, identify the substances numbered.
substance 14

Question 74

In this figure depicting the Stages of Metabolism taken from your text, identify the metabolic substance numbered.
process 11

Question 75

In this figure depicting the Stages of Metabolism taken from your text, identify the metabolic substance numbered.
process 9

Question 76

In this figure, depicting part 1 of the Citric Acid Cycle, taken from your text, identify the substances numbered.
substance 16

Question 77

In this figure, depicting part 1 of the Citric Acid Cycle, taken from your text, identify the substances numbered.
substance 12

Question 78

FADH₂ is the oxidized form of FAD.

Question 79

Cyt c is a component of complex IV.

Question 80

The energy levels of complexes decrease as electron transport progresses.