Deck 8: How Cells Make Atp Energy-Releasing Pathways

Question 1

During the citric acid cycle, each acetyl group entering the cycle yields:

A) 1 ATP, 2 NADH, and 3 FADH₂.
B) 1 ATP, 3 NADH, and 1 FADH₂.
C) 3 ATP, 2 NADH, and 1 FADH₂.
D) 4 ATP, 2 NADH, and 1 FADH₂.
E) 1 ATP, 2 NADH, and 4 FADH₂.

Answer 1

B

Question 2

The energy released during the chain of electron transport molecules is used to create a(n) ____ gradient across the inner mitochondrial membrane for chemiosmosis.

A) ADP
B) ATP
C) proton
D) oxygen
E) electron

Answer 2

C

Question 3

During chemiosmosis, what must be transferred from NADH and FADH₂ to electron acceptor molecules?

A) protons
B) electrons
C) ATP molecules
D) ADP molecules
E) water molecules

Answer 3

B

Question 4

After the conversion of pyruvate molecules to acetyl CoA molecules, how many NADH molecules have been produced from one glucose molecule?

A) one
B) two
C) three
D) four
E) five

Question 5

A glucose molecule that is metabolized via aerobic respiration has been completely broken down and released as CO₂ by the end of:

A) glycolysis.
B) fermentation.
C) the citric acid cycle.
D) the electron transport chain.
E) ATP synthesis in the mitochondria.

Question 6

Which is a product from the first reaction of the citric acid cycle?

A) ATP
B) NAD⁺
C) citrate
D) phosphate
E) acetyl-CoA

Question 7

In glycolysis, a phosphorylated sugar (fructose-1, 6-bisphosphate) is split, forming two molecules of:

A) ADP.
B) G3P.
C) glucose.
D) citric acid.
E) acetyl CoA.

Question 8

Where does the citric acid cycle take place in a eukaryotic cell?

A) nucleus
B) cytosol
C) mitochondrial matrix
D) endoplasmic reticulum
E) mitochondrial membrane

Question 9

Glycolysis yields a net energy profit of ____ ATP molecules per molecule of glucose.

A) no
B) one
C) two
D) four
E) six

Question 10

What does the oxidative decarboxylation of two pyruvates yield?

A) 2 G3P
B) 2 glucose molecules
C) 2 ATP + 4 CO₂ + 2 NADH
D) 1 fructose-1, 6-bisphosphate
E) 2 acetyl CoA + 2 CO₂ + 2 NADH

Question 11

Which reactant of aerobic respiration is oxidized?

A) water
B) oxygen
C) glucose
D) energy
E) carbon dioxide

Question 12

During the first phase of glycolysis, because glucose is relatively stable and not easily broken down, two ____ reactions take place to transfer a phosphate group from ATP to the sugar.

A) redox
B) exergonic
C) metabolic
D) hydrolysis
E) phosphorylation

Question 13

Which reaction is the aerobic respiration of glucose?

A) C₆H₁₂O₆ + 6 H₂O → 6 CO₂ + 12 H₂ + energy
B) C₄H₁₂O₄ + 2 H₂O + 6 CO₂ → 6 O₂ + ATP + energy
C) C₄H₁₂O₄ + 12 O₂ + 6 H₂O → 6 CO₂ + ATP + energy
D) C₆H₁₂O₆ + 6 O₂ + 6 H₂O → 6 CO₂ + 12 H₂O + energy
E) C₄H₁₂O₂ + 6 O₂ + ATP → 6 CO₂ + 12 H₂O + energy

Question 14

What is the chemical reaction illustrated in the figure? ​
​

A) fermentation
B) the first step in the citric acid cycle
C) the energy investing phase of glycolysis
D) part of the electron transport chain
E) the energy capture phase of glycolysis

Question 15

In glycolysis, a six-carbon glucose molecule is converted into two three-carbon molecules of:

A) citrate.
B) acetate.
C) pyruvate.
D) oxaloacetate.
E) coenzyme A

Question 16

Why must the transfer of electrons from glucose to oxygen during aerobic respiration take place in a series of steps?

A) The energy of the protons can be used to make ATP.
B) The energy of the electrons can be used to make ATP.
C) The energy of the electrons can be used to make ADP.
D) It is chemically impossible to transfer electrons directly from glucose to oxygen.
E) The chemical intermediates donate some of their electrons in order to increase the electron pool.

Question 17

In the electron transport chain, exergonic redox processes drive the endergonic reaction in which:

A) pyruvate is converted to acetyl CoA.
B) ATP is produced by phosphorylation of ADP.
C) G3P is produced from phosphorylation of ADP.
D) ADP is produced by dephosphorylation of ATP.
E) glucose is produced from phosphorylation of ADP.

Question 18

During aerobic respiration, nutrients are ____ to carbon dioxide and water.

A) reduced
B) oxidized
C) fermented
D) anabolized
E) catabolized

Question 19

In glycolysis, glucose receives two phosphate groups from ____, thus forming fructose-1, 6-bisphosphate.

A) ADP
B) ATP
C) G3P
D) a bisphosphate group
E) fructose-1, 6-bisphosphate

Question 20

What type of reaction is aerobic respiration?

A) redox
B) anabolic
C) hydrolysis
D) glycolysis
E) polymerization

Question 21

Aerobic respiration is regulated by the binding of ATP or AMP to what enzyme?

A) aldolase
B) isomerase
C) hexokinase
D) phosphofructokinase
E) pyruvate dehydrogenase

Question 22

Which of the following statements about the electron transport chain is true?

A) Protons are pumped out of the mitochondria by the complexes of the electron transport chain.
B) The proton gradient established during electron transport is a form of potential energy.
C) The electron transport chain can be found in the mitochondria of aerobic bacteria and other cells.
D) The movement of protons down a concentration gradient is an endergonic process.
E) ATP synthesis associated with the electron transport chain is an example of substrate level phosphorylation.

Question 23

During aerobic respiration, what molecule is degraded for the formation of acetyl coenzyme A?

A) NAD
B) FADH
C) glucose
D) pyruvate
E) coenzyme A

Question 24

How does anaerobic respiration differ from aerobic respiration?

A) Anaerobic respiration produces CO₂.
B) Anaerobic respiration produces ATP.
C) Anaerobic respiration involves an electron transport chain.
D) Anaerobic respiration utilizes O₂ as the terminal electron acceptor.
E) Anaerobic respiration utilizes NO₃ ⁻ as the terminal electron acceptor.

Question 25

Which of the following statements about lactic acid fermentation is FALSE?

A) It uses glucose as a substrate.
B) It is inefficient compared to aerobic respiration.
C) It produces two ATP molecules for every glucose molecule.
D) Oxygen is the final electron acceptor of this pathway.
E) Glycolysis is the only energy-yielding step of this pathway.

Question 26

Which of the following is an exploited product of lactate fermentation?

A) butter
B) beer
C) yogurt
D) ice cream
E) loaf of bread

Question 27

The electron transport chain forms a concentration gradient for H+, which diffuses through ATP synthase complexes, producing ____.

A) ATP
B) FAD
C) G3P
D) NADH
E) pyruvate

Question 28

In the skeletal muscle cells of vertebrates, as many as ____ ATP molecules are produced from one molecule of glucose, which is less than might be expected because electrons from NADH produced during glycolysis must be shuttled through the ____ mitochondrial membrane at a cost.

A) 2; outer
B) 2; inner
C) 6; outer
D) 36; inner
E) 38; inner

Question 29

What is the role of the oxygen molecules required for aerobic respiration?

A) To form ATP
B) To produce CO₂
C) To accept electrons directly from either NADH or FADH₂
D) To accept the low energy electrons at the end of the electron transport chain
E) To store high energy electrons to pass to complex I of the electron transport chain

Question 30

In chemiosmosis, ATP is produced as hydrogen ions (protons) pass through _____.

A) ATP synthase
B) ATP decarboxylase
C) ATP dehydrogenase
D) a series of electron carriers
E) the outer mitochondrial membrane

Question 31

Saturated fatty acids store more energy than unsaturated fatty acids. Based on your knowledge of aerobic respiration, you draw this conclusion because saturated fatty acids:

A) lack phosphate.
B) are deaminated.
C) contain more ATP.
D) are more highly reduced.
E) contain more ester linkages.

Question 32

Which of the following is an end product of glycolysis?

A) CO₂
B) ATP
C) NAD⁺
D) FADH₂
E) acetyl CoA

Question 33

What is the function of coenzyme Q?

A) To reduce glucose
B) To oxidize glucose
C) To transfer electrons
D) To transfer phosphate to ATP
E) To provide energy in the citric acid cycle

Question 34

One gram of ____ contains more than twice the amount of energy of a gram of glucose.

A) starch
B) lipids
C) ATP
D) protein
E) amino acids

Question 35

Which of the following is an anaerobic pathway?

A) chemiosmosis
B) fermentation
C) citric acid cycle
D) aerobic respiration
E) electron transport chain

Question 36

Peter Mitchell demonstrated ATP production by aerobic bacteria to prove what process?

A) glycolysis
B) hydrolysis
C) fermentation
D) chemiosmosis
E) citric acid cycle

Question 37

Which of the following steps in the citric acid cycle directly produces a molecule of ATP (or GTP)?

A) citrate → isocitrate
B) succinate → fumarate
C) malate → oxaloacetate
D) succinyl CoA → succinate
E) isocitrate → α -ketoglutarate

Question 38

Which of the following molecules can be used as a substrate for cellular respiration?

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

Question 39

In eukaryotes, where does glycolysis occur?

A) cytosol
B) lysosomes
C) Golgi complex
D) mitochondrial matrix
E) mitochondrial inner membrane

Question 40

The complete aerobic metabolism of one molecule of glucose yields a maximum of how many ATPs?

A) 2
B) 4
C) 18
D) 32 to 34
E) 36 to 38

Question 41

Which molecule contains the least stored chemical energy?

A) ethyl alcohol
B) pyruvate
C) glucose
D) lactate
E) oxygen

Question 42

If yeast cells are incubated under anaerobic conditions, the pyruvate they produce is converted to lactate .
__________________

Question 43

Identify and briefly describe the process(es) of cellular respiration that occur in the mitochondria. Indicate the amount of ATP, NADH, and FADH₂ produced in each process.

Question 44

In liver cells, each NADH produced via glycolysis results in two ATP molecules in the electron transport chain.
__________________

Question 45

Explain how proteins can be metabolized by the same pathways that oxidize glucose.

Question 46

What is chemiosmosis, and how is it used to synthesize ATP? Use the following terms in your explanation: inner mitochondria membrane, mitochondrial matrix, endergonic, exergonic, ADP, P_i, and NADH/FADH₂.

Question 47

The reactions of the citric acid cycle take place in the matrix of the mitochondrion.
__________________

Question 48

If yeasts are grown under anaerobic conditions, pyruvate is converted first to ____ and then to ____.

A) citrate; oxaloacetate
B) acetaldehyde; lactate
C) lactate; carbon dioxide
D) acetaldehyde; ethyl alcohol
E) acetyl coenzyme A; citrate

Question 49

Phosphofructokinase is stimulated by high levels of ATP.
__________________

Question 50

During fermentation, the immediate fate of the electrons in NADH is that they:

A) are transferred to the electron transport chain.
B) are transferred to an organic molecule.
C) are transferred to O₂.
D) are used to make CO₂.
E) are used to form H₂O.

Question 51

Both alcohol fermentation and lactate fermentation are highly ____ because the fuel is only partially ____.

A) efficient; reduced
B) efficient; oxidized
C) inefficient; reduced
D) inefficient; oxidized
E) efficient; metabolized

Question 52

Substrate level phosphorylation reactions occur in the process of chemiosmosis.
__________________

Question 53

An example of a(n) anabolic reaction is the splitting of a polysaccharide into monosaccharides.
__________________

Question 54

The stage of cellular respiration in which most of the ATP is produced is the citric acid cycle. __________________

Question 55

Alcohol is the end product of fermentation by what type of organism?

A) cow
B) algae
C) yeast
D) protist
E) bacteria

Question 56

In the tricarboxylic acid cycle, oxaloacetate reacts with acetyl CoA forming citrate .
__________________

Question 57

For each glucose molecule that begins cellular respiration, the citric acid cycle must turn once .
__________________

Question 58

For each acetyl CoA molecule that enters the citric acid cycle, two CO₂ molecules are produced.
__________________

Question 59

The downhill flow of protons through the ATP synthase complex powers the production of ATP.
__________________

Question 60

Compare and contrast aerobic and anaerobic pathways used by cells to extract energy from organic molecules. Include the mechanism of ATP formation, the final electron acceptor, and the end products in your comparison.

Question 62

Although our muscle cells contain mitochondria and normally undergo aerobic respiration, during strenuous activity, lactate is formed, which contributes to cramps in our muscles. What is the evolutionary advantage of lactate production in our cells?

Question 63

What is the major difference between substrate-level phosphorylation and oxidative phosphorylation?

Question 64

In the process of aerobic respiration, nitrate can function as the terminal electron acceptor in the electron transport chain.
__________________

Question 65

Describe how cells can regulate aerobic respiration at the level of the conversion of glucose-6-phosphate to fructose-1, 6-bisphosphate as catalyzed by phosphofructokinase (PFK).

Question 66

Explain why fermentation is a highly inefficient process.