Question 1

Humans use about ________ of their daily calories to maintain brain cells and power other life-sustaining activities.

Accepted Answer

A)  25% 
B)  50% 
C)  75% 
D)  90% 
A)  25% 
B)  50% 
C)  75% 
D)  90% C

Question 2

Marathon runners are long-distance runners (marathons are races that are 26.2 miles long). Studies have shown that the muscles of marathon runners contain an abundance of slow-twitch muscle cells. Which of the following statements about these fibers is true?

Accepted Answer

A)  Slow-twitch fibers have lots of mitochondria to make ATP aerobically. 
B)  Slow-twitch fibers have lots of mitochondria to make ATP through fermentation. 
C)  Slow-twitch fibers have few mitochondria and make ATP aerobically. 
D)  Slow-twitch fibers have few mitochondria and make ATP through fermentation. 
A)  Slow-twitch fibers have lots of mitochondria to make ATP aerobically. 
B)  Slow-twitch fibers have lots of mitochondria to make ATP through fermentation. 
C)  Slow-twitch fibers have few mitochondria and make ATP aerobically. 
D)  Slow-twitch fibers have few mitochondria and make ATP through fermentation. A

Question 3

When an organism such as a yeast lives by fermentation, it converts the pyruvate from glycolysis into a different compound, such as alcohol. Why doesn't it secrete the pyruvate directly?

Accepted Answer

A)  The conversion yields 32 ATP per pyruvate molecule. 
B)  The conversion yields 1 NADH per pyruvate molecule. 
C)  The conversion is needed to regenerate the molecules needed for glycolysis. 
D)  A buildup of pyruvate in the surrounding environment would be too toxic. 
A)  The conversion yields 32 ATP per pyruvate molecule. 
B)  The conversion yields 1 NADH per pyruvate molecule. 
C)  The conversion is needed to regenerate the molecules needed for glycolysis. 
D)  A buildup of pyruvate in the surrounding environment would be too toxic. C

Question 4

During redox reactions,

Accepted Answer

A)  the loss of electrons from one molecule is called reduction. 
B)  electrons are lost from one substance and added to another substance. 
C)  protons from one molecule replace the electrons lost from another molecule. 
A)  the loss of electrons from one molecule is called reduction. 
B)  electrons are lost from one substance and added to another substance. 
C)  protons from one molecule replace the electrons lost from another molecule.

Question 5

The end products of the citric acid cycle include all of the following except

Accepted Answer

A)  CO2. 
B)  pyruvate. 
C)  ATP. 
D)  FADH2. 
A)  CO2. 
B)  pyruvate. 
C)  ATP. 
D)  FADH2.

Question 6

The label on the box of breakfast cereal lists one serving as containing "200 Calories" per serving. How many calories are actually in one serving?

Accepted Answer

A)  20 
B)  2,000 
C)  200,000 
D)  2,000,000 
A)  20 
B)  2,000 
C)  200,000 
D)  2,000,000

Question 7

A drug is tested in the laboratory and is found to create holes in both mitochondrial membranes. Scientists suspect that the drug will be harmful to human cells because it will inhibit

Accepted Answer

A)  the citric acid cycle only. 
B)  oxidative phosphorylation only. 
C)  glycolysis only. 
D)  the citric acid cycle and oxidative phosphorylation. 
A)  the citric acid cycle only. 
B)  oxidative phosphorylation only. 
C)  glycolysis only. 
D)  the citric acid cycle and oxidative phosphorylation.

Question 8

When a cell uses fatty acids for aerobic respiration, it first hydrolyzes fats to

Accepted Answer

A)  glycerol and amino acids. 
B)  glycerol and fatty acids. 
C)  fatty acids and sugars. 
D)  sugars and glycerol. 
A)  glycerol and amino acids. 
B)  glycerol and fatty acids. 
C)  fatty acids and sugars. 
D)  sugars and glycerol.

Question 9

Which of the following statements about the energy yield of aerobic respiration is false?

Accepted Answer

A)  Glycolysis resulting from 1 glucose molecule yields 2 ATP molecules. 
B)  The oxidation of pyruvate results in the production of 0 ATP molecules. 
C)  Oxidative phosphorylation resulting from 1 glucose molecule yields 12 ATP molecules. 
D)  The citric acid cycle resulting from 1 glucose molecules yields 2 ATP molecules. 
A)  Glycolysis resulting from 1 glucose molecule yields 2 ATP molecules. 
B)  The oxidation of pyruvate results in the production of 0 ATP molecules. 
C)  Oxidative phosphorylation resulting from 1 glucose molecule yields 12 ATP molecules. 
D)  The citric acid cycle resulting from 1 glucose molecules yields 2 ATP molecules.

Question 10

Yeasts can produce ATP by either fermentation or oxidative phosphorylation; thus, they are

Accepted Answer

A)  strict anaerobes. 
B)  strict aerobes. 
C)  facultative anaerobes. 
D)  facultative aerobes. 
A)  strict anaerobes. 
B)  strict aerobes. 
C)  facultative anaerobes. 
D)  facultative aerobes.

Question 11

To obtain energy from starch and glycogen, the body must begin by

Accepted Answer

A)  hydrolyzing the starch to glucose and the glycogen to amino acids. 
B)  hydrolyzing both starch and glycogen to glucose. 
C)  converting both starch and glycogen to fatty acids. 
D)  removing one glucose at a time with a condensation reaction. 
A)  hydrolyzing the starch to glucose and the glycogen to amino acids. 
B)  hydrolyzing both starch and glycogen to glucose. 
C)  converting both starch and glycogen to fatty acids. 
D)  removing one glucose at a time with a condensation reaction.

Question 12

If you consume 1 g of each of the following, which will yield the most ATP?

Accepted Answer

A)  fat 
B)  glucose 
C)  protein 
D)  starch 
A)  fat 
B)  glucose 
C)  protein 
D)  starch

Question 13

The enzymes of the citric acid cycle are located in the

Accepted Answer

A)  cytoplasm. 
B)  outer mitochondrial membrane. 
C)  nucleus. 
D)  mitochondrial matrix and inner mitochondrial membrane. 
A)  cytoplasm. 
B)  outer mitochondrial membrane. 
C)  nucleus. 
D)  mitochondrial matrix and inner mitochondrial membrane.

Question 14

How do cells capture the energy released by cellular respiration?

Accepted Answer

A)  They produce ATP. 
B)  They produce glucose. 
C)  They store energy in molecules of carbon dioxide. 
D)  The energy is coupled to oxygen. 
A)  They produce ATP. 
B)  They produce glucose. 
C)  They store energy in molecules of carbon dioxide. 
D)  The energy is coupled to oxygen.

Question 15

Which step of the citric acid cycle requires both NAD+ and ADP as reactants?

Accepted Answer

A)  step 1 
B)  step 2 
C)  step 3 
D)  step 4 
A)  step 1 
B)  step 2 
C)  step 3 
D)  step 4

Question 16

As a scientist employed by the FDA, you've been asked to sit on a panel to evaluate a pharmaceutical company's application for approval of a new weight loss drug called Fat Away. The company has submitted a report summarizing the results of their animal and human testing. In the report, it was noted that Fat Away works by affecting the electron transport chain. It decreases the synthesis of ATP by making the mitochondrial membrane permeable to H+, which allows H+ to leak from the intermembrane space to the mitochondrial matrix. This effect leads to weight loss.
-You predict that a side effect of Fat Away will be increased

Accepted Answer

A)  production of NADH. 
B)  production of pyruvate. 
C)  production of lactate. 
D)  body temperature. 
A)  production of NADH. 
B)  production of pyruvate. 
C)  production of lactate. 
D)  body temperature.

Question 17

The function of coenzyme A in the citric acid cycle is most like

Accepted Answer

A)  a limousine driver dropping off a couple at the school prom. 
B)  a frog that turns into a prince. 
C)  a kid jumping up and down on a trampoline. 
D)  throwing a baited hook into a lake and catching a fish. 
A)  a limousine driver dropping off a couple at the school prom. 
B)  a frog that turns into a prince. 
C)  a kid jumping up and down on a trampoline. 
D)  throwing a baited hook into a lake and catching a fish.

Question 18

After glycolysis but before the citric acid cycle

Accepted Answer

A)  pyruvate is oxidized. 
B)  a carbon atom is added to pyruvate to make a four-carbon compound. 
C)  coenzyme A is cleaved off pyruvate. 
D)  glucose is split, producing two molecules of pyruvate. 
A)  pyruvate is oxidized. 
B)  a carbon atom is added to pyruvate to make a four-carbon compound. 
C)  coenzyme A is cleaved off pyruvate. 
D)  glucose is split, producing two molecules of pyruvate.

Question 19

As a scientist employed by the FDA, you've been asked to sit on a panel to evaluate a pharmaceutical company's application for approval of a new weight loss drug called Fat Away. The company has submitted a report summarizing the results of their animal and human testing. In the report, it was noted that Fat Away works by affecting the electron transport chain. It decreases the synthesis of ATP by making the mitochondrial membrane permeable to H+, which allows H+ to leak from the intermembrane space to the mitochondrial matrix. This effect leads to weight loss.
-Fat Away prevents ATP from being made by

Accepted Answer

A)  eliminating the H+ gradient that allows ATP synthase to work. 
B)  preventing glycolysis from occurring. 
C)  preventing the conversion of NADH to NAD+. 
D)  slowing down the citric acid cycle. 
A)  eliminating the H+ gradient that allows ATP synthase to work. 
B)  preventing glycolysis from occurring. 
C)  preventing the conversion of NADH to NAD+. 
D)  slowing down the citric acid cycle.

Question 20

When proteins are used as a source of energy for the body, the proteins

Accepted Answer

A)  are converted into glucose molecules, which are fed into glycolysis. 
B)  are converted mainly into intermediates of glycolysis or the citric acid cycle. 
C)  donate electrons directly to the electron transport chain. 
D)  are hydrolyzed to glucose and converted to acetyl CoA, which enters the citric acid cycle. 
A)  are converted into glucose molecules, which are fed into glycolysis. 
B)  are converted mainly into intermediates of glycolysis or the citric acid cycle. 
C)  donate electrons directly to the electron transport chain. 
D)  are hydrolyzed to glucose and converted to acetyl CoA, which enters the citric acid cycle.

Exam 6: How Cells Harvest Chemical Energy

Humans use about ________ of their daily calories to maintain brain cells and power other life-sustaining activities.

Marathon runners are long-distance runners (marathons are races that are 26.2 miles long). Studies have shown that the muscles of marathon runners contain an abundance of slow-twitch muscle cells. Which of the following statements about these fibers is true?

When an organism such as a yeast lives by fermentation, it converts the pyruvate from glycolysis into a different compound, such as alcohol. Why doesn't it secrete the pyruvate directly?

During redox reactions,

The end products of the citric acid cycle include all of the following except

The label on the box of breakfast cereal lists one serving as containing "200 Calories" per serving. How many calories are actually in one serving?

A drug is tested in the laboratory and is found to create holes in both mitochondrial membranes. Scientists suspect that the drug will be harmful to human cells because it will inhibit

When a cell uses fatty acids for aerobic respiration, it first hydrolyzes fats to

Which of the following statements about the energy yield of aerobic respiration is false?

Yeasts can produce ATP by either fermentation or oxidative phosphorylation; thus, they are

To obtain energy from starch and glycogen, the body must begin by

If you consume 1 g of each of the following, which will yield the most ATP?

The enzymes of the citric acid cycle are located in the

How do cells capture the energy released by cellular respiration?

Which step of the citric acid cycle requires both NAD+ and ADP as reactants?

The function of coenzyme A in the citric acid cycle is most like

After glycolysis but before the citric acid cycle

When proteins are used as a source of energy for the body, the proteins

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