Ch. 7: Cellular Respiration + Fermentation

Question 1

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 1

carbon dioxide

Question 2

The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the __________.

Answer 2

H+ concentration across the membrane holding ATP synthase

Question 3

If muscle cells in the human body consume O2 faster than it can be supplied, which of the following is likely to result?

Answer 3

All of the listed events will occur (trouble makung ATP, cosume glucose @ increased rate, not able to carry out O phosphorylation)

Question 4

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

Answer 4

In the cytosol

Question 5

The overall efficiency of respiration (the percentage of the energy released that is saved in ATP) is approximately __________.

Answer 5

34%

Question 6

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

Answer 6

NADH

Question 7

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

Answer 7

NAD+

Question 8

Most of the NADH that delivers electrons to the electron transport chain comes from which of the following processes?

Answer 8

The citric acid cycle

Question 9

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

Answer 9

All of the listed substances are involved in oxidative phosphorylation. (ADP, ATP, O)

Question 10

Why is the citric acid cycle called a cycle?

Answer 10

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

Question 11

Molecular oxygen (O2) has what role in aerobic cellular respiration?

Answer 11

It is the final electron acceptor at the end of the electron transport chain.

Question 12

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 12

Two ATP, six NADH, two FADH2

Question 13

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 13

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

Question 14

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

Answer 14

glucose; oxygen

Question 15

Of the metabolic pathways listed below, which is the most universal metabolic process associated with cellular respiration?

Answer 15

Glycolysis

Question 16

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

Answer 16

Oxidative phosphorylation

Question 17

The electron transport chain involved in cellular respiration is located in/on the __________.

Answer 17

inner membrane of the mitochondrion

Question 18

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

Answer 18

The matrix of the mitochondrion

Question 19

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

Answer 19

None of the listed responses is correct. (Correct is glycolysis)

Question 20

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

Answer 20

Oxidation of glucose to pyruvate; oxidation of pyruvate; oxidation of acetyl-coA; oxidative phosphorylation [GP< P<A<O]

Question 21

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

Answer 21

Oxygen

Question 22

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 22

Four

Question 23

A molecule becomes oxidized when it __________.

Answer 23

loses an electron

Question 24

Of the following molecules in the glycolytic pathway (the process of glycolysis), the one with the most chemical energy is __________.

Answer 24

fructose-1,6-bisphosphate

Question 25

Which of the following best describes the electron transport chain of cellular respiration?

Answer 25

Electrons are passed from one carrier to another, releasing a little energy at each step.