Deck 6: Respiration

Question 1

In respiration, most of the energy in the original glucose molecule is:

A)stored in molecules of ADP.
B)stored in molecules of ATP.
C)stored in molecules of pyruvate.
D)released in molecules of carbon dioxide.
E)released as heat.

Answer 1

E

Question 2

When one speaks of the cell's "net energy harvest" from glycolysis one is referring to the amount of:

A)ATP only.
B)ADP only.
C)NAD⁺ only.
D)NADH only
E)ATP and NADH.

Answer 2

E

Question 3

Which of the following statements about the reactions of glucose oxidation is FALSE?

A)The glucose molecule is hydrolyzed.
B)Hydrogen atoms are removed.
C)Oxygen is oxidized.
D)Energy is released.
E)Electrons go from higher to lower energy levels.

Answer 3

C

Question 4

As part of the first step in the first preparatory reaction of glycolysis:

A)the glucose molecule is rearranged.
B)the glucose molecule is split in half.
C)glucose is phosphorylated.
D)NAD⁺ is reduced.
E)NADH is oxidized.

Question 5

Which of the following does NOT occur during respiration?

A)hydrolysis of starch to glucose
B)formation of acetyl CoA
C)electron transport chain
D)citric acid cycle
E)glycolysis

Question 6

The preparatory phase of glycolysis involves:

A)2 molecules of ATP only.
B)2 molecules of NAD⁺ only.
C)2 molecules of NADH only.
D)1 molecule of ATP and 1 molecule of NADH.
E)1 molecule of ATP and 1 molecule of NAD⁺.

Question 7

Pyruvate is converted to acetyl CoA in the ____ of the _____.

A)cytosol; cell
B)matrix; mitochondria
C)lumen; smooth ER
D)cristae; mitochondria
E)ribosomes; rough ER

Question 8

In glycolysis, one molecule of glucose is converted to ______ molecules of ______.

A)two; fructose
B)three; fructose.
C)two; pyruvate
D)three; pyruvate
E)two; sucrose

Question 9

For each molecule of glucose that completes glycolysis, how many NAD⁺ molecules are reduced?

A)0
B)1
C)2
D)3
E)4

Question 10

During the conversion of pyruvate to acetyl CoA, _____ is produced.

A)CO₂
B)ATP
C)NAD⁺
D)ADP
E)3-phosphoglycerate

Question 11

Where in the cell does glycolysis occur?

A)the cytosol
B)mitochondria
C)the nucleus
D)the endoplasmic reticulum
E)chloroplasts

Question 12

As part of the cleavage step in glycolysis, glucose is:

A)converted to glyceraldehyde 3-phosphate and dihydroxyacetone phosphate.
B)phosphorylated to glucose 6-phosphate.
C)oxidized to 1,3-bisphosphoglycerate.
D)reduced to phosphoenolpyruvate.
E)converted by the enzyme isomerase to fructose.

Question 13

Which of the following statements concerning glycolysis is FALSE?

A)It is considered a primitive process.
B)It is an aerobic process.
C)It occurs in a series of 10 steps.
D)It is carried out by virtually all cells.
E)Its reactions are catalyzed by specific enzymes.

Question 14

For every molecule of glucose that begins glycolysis, how many ATP molecules are consumed?

A)0
B)1
C)2
D)3
E)4

Question 15

Most of the enzymes of the citric acid cycle are found in the _____ of the _____.

A)cytosol; cell
B)matrix; mitochondria
C)lumen; smooth ER
D)cristae; mitochondria
E)ribosomes; rough ER

Question 16

For every glucose molecule that completes glycolysis, how many total molecules of ATP are produced?

A)0
B)1
C)2
D)3
E)4

Question 17

For every molecule of glucose that begins glycolysis, how many molecules of acetyl CoA are produced?

A)0
B)1
C)2
D)3
E)4

Question 18

Formation of ATP from ADP and phosphate as a result of electron transport occurs in:

A)the citric acid cycle.
B)the formation of acetyl CoA.
C)fermentation.
D)glycolysis.
E)oxidative phosphorylation.

Question 19

In glycolysis, what is the net energy harvest of ATP molecules per molecule of glucose?

A)0
B)1
C)2
D)3
E)4

Question 20

Which of the following statements concerning fermentation is FALSE?

A)It occurs under anaerobic conditions.
B)It involves O₂ as the ultimate electron acceptor.
C)It involves the breakdown of organic molecules.
D)It releases less than 686 kcal/mole of glucose.
E)It is an exergonic process.

Question 21

In each turn of the citric acid cycle, how many molecules of ATP are produced?

A)0
B)1
C)2
D)3
E)4

Question 22

In the citric acid cycle, how many molecules of NADH are produced per molecule of glucose?

A)0
B)1
C)2
D)4
E)6

Question 23

The energy released by the flow of electrons along the electron transport chain is used directly to:

A)form ATP from ADP and phosphate.
B)oxidize NADH.
C)reduce FAD.
D)decarboxylate citrate.
E)pump protons.

Question 24

In the electron transport chain, electrons pass from complex ____ directly to O₂.

A)I
B)II
C)III
D)IV
E)V

Question 25

Who am I? I move freely within the mitochondrial membrane and thus shuttle electrons between other carriers.

A)CoQ
B)Fe-S proteins
C)cytochromes
D)cytochrome oxidase
E)CoA

Question 26

For each pair of electrons passing from NADH to oxygen, how many ATP molecules can be generated?

A)0
B)1
C)2
D)3
E)4

Question 27

The most abundant component(s) of the mitochondrial electron transport chain is/are:

A)cytochromes.
B)iron-sulfur proteins.
C)coenzyme Q.
D)NAD⁺.
E)FAD.

Question 28

Upon entering the citric acid cycle, the acetyl group combines with ______ to produce ______.

A)coenzyme A; pyruvate
B)glucose; glucose 6-phosphate
C)oxaloacetate; citrate
D)oxaloacetate; carbon dioxide
E)NADH; citrate

Question 29

The electrochemical gradient resulting from electron transport is due to differences in ______ across the inner mitochondrial membrane.

A)only the electric charge
B)proton concentration only
C)electric charge and proton concentration
D)only the ATP concentration
E)ATP and NAD⁺ concentrations

Question 30

Which of the following does NOT occur during the citric acid cycle?

A)decarboxylation
B)substrate-level phosphorylation
C)oxidation
D)oxidative phosphorylation
E)regeneration of oxaloacetate

Question 31

In the citric acid cycle, how many molecules of FADH are produced per molecule of glucose?

A)0
B)1
C)2
D)3
E)4

Question 32

The number of ATP molecules generated from each NADH produced in the conversion of pyruvate to acetyl CoA is _______.

A)0
B)1
C)2
D)3
E)4

Question 33

After acetyl CoA enters the citric acid cycle, the coenzyme A portion of the molecule:

A)combines with oxaloacetate.
B)combines with citrate.
C)is oxidized.
D)is reduced.
E)is released.

Question 34

Oxidative phosphorylation depends on a gradient of ______ across the mitochondrial membrane.

A)ADP
B)phosphate
C)glucose
D)protons
E)electrons

Question 35

Which of the following statements about ATP synthase is FALSE?

A)It synthesizes ATP.
B)It transports electrons.
C)It binds phosphate.
D)It binds ADP.
E)It transports hydrogen ions.

Question 36

The number of ATP molecules generated from each NADH produced in glycolysis is _______.

A)0
B)1
C)2
D)3
E)4

Question 37

The final electron acceptor in the electron transport chain is:

A)CoQ.
B)a cytochrome.
C)FMN.
D)oxygen.
E)carbon dioxide.

Question 38

Which of the following statements about iron-sulfur proteins is FALSE?

A)They are components of the electron transport chain.
B)Their iron is not attached to a porphyrin ring.
C)Their iron is attached to sulfides.
D)Their iron is attached to the sulfur of sulfur-containing amino acids.
E)They carry electrons and protons.

Question 39

Most of the carriers of the electron transport chain are:

A)in the cytosol.
B)in the mitochondrial matrix.
C)contained between the outer and inner mitochondrial membranes.
D)embedded in the inner mitochondrial membrane.
E)embedded in the outer mitochondrial membrane.

Question 40

Most of the ATP formed in respiration is produced by reactions associated with:

A)the electron transport chain.
B)the citric acid cycle.
C)glycolysis.
D)fermentation.
E)the conversion of pyruvate to acetyl CoA.

Question 41

The complete oxidation of one molecule of glucose requires two turns around the citric acid cycle.

Question 42

Cytochromes are unique electron carriers in that they can accept protons as well as electrons.

Question 43

"Catabolism" specifically refers to the various pathways in which organisms ______ organic molecules.

A)synthesize
B)break down
C)phosphorylate
D)oxidize
E)reduce

Question 44

In the citric acid cycle, NADH is produced in some reactions, but it is not consumed.

Question 45

Ubiquinone is also called coenzyme Q.

Question 46

In the citric acid cycle, carbon dioxide is produced in some reactions, but it is not consumed.

Question 47

At the end of glycolysis, most of the energy in the original glucose molecule is still present in pyruvate.

Question 48

The inner mitochondrial membrane is permeable to most small molecules and ions.

Question 49

The metabolic "hub" of the cell is:

A)fermentation.
B)glycolysis.
C)oxidative phosphorylation.
D)the electron transport chain.
E)the citric acid cycle.
True-False Questions

Question 50

In glycolysis, ATP is consumed in some reactions and produced in others.

Question 51

In glycolysis, NADH is consumed in some reactions and produced in others.

Question 52

The complete oxidation of one molecule of glucose requires two turns around the citric acid cycle.

Question 53

For each pair of electrons that passes from NADH to oxygen, three molecules of ATP are formed during oxidative phosphorylation.

Question 54

More energy is obtained when glucose is oxidized under aerobic conditions rather than anaerobic conditions.

Question 55

Under anaerobic conditions, yeasts and most plant cells convert pyruvate to:

A)acetyl CoA.
B)lactate.
C)ethanol and carbon dioxide.
D)ATP.
E)glucose.

Question 56

After glycolysis is completed, the carbon atoms present in a pyruvate molecule move directly into the citric acid cycle.

Question 57

Which of the following processes occurs in both lactate fermentation and alcohol fermentation?

A)formation of acetyl CoA
B)release of carbon dioxide
C)pumping of protons
D)oxidation of NADH
E)activation of ATP synthase

Question 58

In lactate fermentation and alcohol fermentation, the net ATP production is ______ molecules of ATP per molecule of glucose.

A)0
B)1
C)2
D)3
E)4

Question 59

In the citric acid cycle, ATP is produced in some reactions and consumed in others.

Question 60

The process of beta oxidation is involved in the breakdown of:

A)starch.
B)sucrose.
C)proteins.
D)nucleic acids.
E)triglycerides.

Question 61

Without a proton gradient across the inner mitochondrial membrane, chemiosmotic coupling cannot occur.

Question 62

For each glucose molecule that begins respiration, 38 ATPs are formed.

Question 63

ATP synthase catalyzes the synthesis of ATP from ADP and phosphate.

Question 64

The NADH generated during fermentation donates its electrons to the mitochondrial electron transport chain.

Question 65

Each NADH molecule produced in glycolysis is transported across the mitochondrial membrane at a "cost" of one ATP.

Question 66

The hydrolysis of starch to sugars is an example of an anabolic reaction.