Deck 23: Metabolism and Energy Production

Question 1

During the first reaction in the citric acid cycle,

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

Answer 1

HS- CoA is released.

Question 2

Which coenzyme is the electron acceptor in the following reaction?

A)FAD
B)NAD+
C)FMN
D)NADH
E)FADH₂

Answer 2

FAD

Question 3

Which coenzyme is the electron acceptor in the following reaction?

A)FAD
B)NAD⁺
C)FMN
D)NADH
E)FADH₂

Answer 3

NAD⁺

Question 4

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 5

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 6

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

A)Acetyl CoA + 3 NAD+ + FAD + GDP + Pi + 2H₂O → 2CO₂ + 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 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 + 2 Pi → 2Lactate + 2GTP

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

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 9

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.

Question 10

The citric acid cycle takes place in the

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

Question 11

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

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

Question 12

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

A)24
B)12
C)10
D)14
E)2

Question 13

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 14

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.

Question 15

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 16

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 17

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 18

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

A)FAD only
B)NAD+ only
C)NADH + FADH2 + HS - CoA
D)FMN
E)NAD+ + FAD

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

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

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

Question 21

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

A)HS-CoA.
B)HO-CoA.
C)CoA-O-.
D)CoA-S-.
E)CoA-COO-.

Question 22

The last step in the citric acid cycle converts malate to

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

Question 23

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 24

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

A)CoQ.
B)CoQH₂.
C)FADH.
D)FAD.
E)NAD+.

Question 25

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 26

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

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

Question 27

Cyanide ion and carbon monoxide inhibit

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

Question 28

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 29

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 30

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

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

Question 31

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 32

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 33

The components of the electron transport chain do NOT include

A)oxygen (O₂).
B)Cyt c.
C)Complex III.
D)CoQ.
E)acetyl CoA.

Question 34

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 35

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 36

The electron carrier ________ provides 1.5 ATP via electron transport.

A)FADH₂
B)NADH
C)NADPH
D)HS-CoA
E)acetyl CoA

Question 37

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

A)Cyt c.
B)FMN.
C)Complex III.
D)CoQ.
E)ATP synthase.

Question 38

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 39

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

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

Question 40

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 41

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

Question 42

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

Question 43

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)32

Question 44

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 45

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

Question 46

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

Question 47

One example of an electron carrier in the respiratory chain is

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

Question 48

The energy released during electron transport is used to produce

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

Question 49

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

A)2
B)4
C)7
D)8
E)12

Question 50

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

Question 51

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

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

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 54

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 55

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 56

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

Question 57

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 58

The complete oxidation of glucose produces ________ ATP molecules.

A)2
B)8
C)12
D)24
E)32

Question 59

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 60

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

Question 61

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

Question 62

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

Question 63

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

Question 64

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

Question 65

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

Question 66

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

Question 67

NAD+ acts as a hydrogen acceptor in metabolic reactions.

Question 68

The oxidation of NADH yields 2.5 ATP.

Question 69

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

Question 70

FADH2 is the oxidized form of FAD.

Question 71

Cyt c is a component of complex IV.

Question 72

The energy levels of complexes decrease as electron transport progresses.

Question 73

Citrate is one of the products of the citric acid cycle.

Question 74

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

Question 75

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

Question 76

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

Question 77

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

Question 78

In reaction 1 of the citric acid cycle, acetyl CoA reacts with oxaloacetate.

Question 79

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

Question 80

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