Chapter 9 (Cellular Respiration and Fermentation)

Question 1

A molecule becomes more oxidized when it __________.

Answer 1

loses an electron

Question 2

In the overall process of glycolysis and cellular respiration, __________ is oxidized and __________ is reduced.

Answer 2

glucose; oxygen

Question 3

Most of the ATP produced in cellular respiration comes from which of the following processes?

Answer 3

Oxidative phosphorylation

Question 4

Which of the following is a correct description of the events of cellular respiration in proper sequence?

Answer 4

Oxidation of glucose to pyruvate; oxidation of pyruvate; citric acid cycle; oxidative phosphorylation

Question 5

Oxygen gas (O2) is one of the strongest oxidizing agents known. The explanation for this is that

Answer 5

the oxygen atom is very electronegative

Question 6

The function of cellular respiration is to __________.

Answer 6

extract usable energy from glucose

Question 7

During the reaction C6H12O6 + 6 O2 → 6 CO2 + 6 H2O, which compound is reduced as a result of the reaction?

Answer 7

Oxygen

Question 8

Which of the following statements is the best explanation of what happens to the temperature and carbon dioxide concentration during a 1-hour class period in a classroom of 300 students if the heating and air-conditioning is turned off and all doors are kept closed?

Answer 8

Temperature and the level of carbon dioxide rise as heat and carbon dioxide are by-products of cellular respiration.

Question 9

A small amount of ATP is made in glycolysis by which of the following processes?

Answer 9

Transfer of a phosphate group from a fragment of glucose to ADP by substrate-level phosphorylation

Question 10

Where do the reactions of glycolysis occur in a eukaryotic cell?

Answer 10

The cytosol

Question 11

Which of the following is the process in which glucose is oxidized to generate two molecules of pyruvate and in which ATP and NADH are produced?

Answer 11

None of the listed responses is correct.

the name of the process that oxidizes glucose to pyruvate and produces ATP and NADH is glycolysis.

Question 12

A chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to kill bacteria in people with infections. However, he cannot do this because __________.

Answer 12

human cells must also perform glycolysis; the drug might also poison them

Question 13

There is no production of carbon dioxide in glycolysis. Which of the following is the best explanation for this fact?

Answer 13

The products of glycolysis contain the same total number of carbon atoms as in the starting material.

Question 14

Which of the following molecules in the process of glycolysis possesses the most chemical energy?

Answer 14

Fructose-1,6-bisphosphate

Question 15

Which of the following processes generates most of the NADH that delivers electrons to the electron transport chain?

Answer 15

The citric acid cycle

Question 16

In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive oxygen. The mice were closely monitored, and after a few minutes, radioactive oxygen atoms showed up in __________.

Answer 16

carbon dioxide

Question 17

In preparing pyruvate to enter the citric acid cycle, which of the following steps occurs?

Answer 17

Pyruvate is oxidized, and a molecule of carbon dioxide is removed. The electrons removed in this process are used to reduce NAD+ to NADH.

Question 18

Why is the citric acid cycle called a “cycle”?

Answer 18

The four-carbon acid that accepts the acetyl CoA in the first step of the cycle is regenerated by the last step of the cycle.

Question 19

In the citric acid cycle, for each pyruvate that enters the cycle, one ATP, three NADH, and one FADH2 are produced. For each glucose molecule that enters glycolysis, how many ATP, NADH, and FADH2 are produced in the citric acid cycle?

Answer 19

Two ATP, six NADH, two FADH

Question 20

Where do the reactions of the citric acid cycle occur in eukaryotic cells?

Answer 20

The matrix of the mitochondrion

Question 21

How many molecules of ATP are gained by substrate-level phosphorylation from the complete breakdown of a single molecule of glucose in the presence of oxygen?

Answer 21

4

Question 22

Which of the following represents the major energy-related accomplishment of the citric acid cycle, even though it is not the only energy-related accomplishment?

Answer 22

Formation of NADH and FADH2

Question 23

After completion of the citric acid cycle, most of the usable energy from the original glucose molecule is in the form of __________.

Answer 23

NADH

Question 24

Which of the following events accompanies the conversion of pyruvate to acetyl CoA before the citric acid cycle?

Answer 24

Release of CO2 and synthesis of NADH

Question 25

The energy given up by electrons as they move through the electron transport chain is used in which of the following processes?

Answer 25

Pumping H+ across a membrane

Question 26

Energy for synthesizing ATP is obtained by ATP synthase directly from which of the following processes?

Answer 26

The flow of H+ across the inner mitochondrial membrane through the ATP synthase enzyme

Question 27

When a poison such as cyanide blocks the electron transport chain, glycolysis and the citric acid cycle also eventually stop working. Which of the following is the best explanation for this?

Answer 27

NAD+ and FAD are not available for glycolysis and the citric acid cycle to continue.

Question 28

Most of the electrons removed from glucose by cellular respiration are used for which of the following processes?

Answer 28

The first two choices are correct.

Question 29

Each ATP molecule contains about 1% of the amount of chemical energy available from the complete oxidation of a single glucose molecule. Cellular respiration produces about 32 ATP from one glucose molecule. What happens to the rest of the energy in glucose?

Answer 29

It is converted to heat.

Question 30

Of the listed metabolic pathways, which is the only pathway found in all organisms?

Answer 30

Glycolysis

Question 31

In brewing beer, maltose (a disaccharide of glucose) is __________. (

Answer 31

the substrate for alcoholic fermentation

Question 32

Which of the following substances is/are involved in oxidative phosphorylation?

Answer 32

ADP Oxygen ATP

Question 33

Which of the following is the source of the energy that produces the chemiosmotic gradient in mitochondria?

Answer 33

Movement of electrons down the electron transport chain

Question 34

In eukaryotic cells, the components of the electron transport chain are located in or on __________.

Answer 34

the inner membrane of the mitochondrion

Question 35

In glycolysis in the absence of oxygen, cells need a way to regenerate which compound?

Answer 35

NAD+