Question 1

Which of the following most accurately describes what is happening along the electron transport chain in Figure 7.2?

Accepted Answer

A)  Chemiosmosis is coupled with electron transfer. 
B)  Each electron carrier alternates between being reduced and being oxidized. 
C)  ATP is generated at each step. 
D)  Energy of the electrons increases at each step. 
E)  Molecules in the chain give up some of their potential energy. 
A)  Chemiosmosis is coupled with electron transfer. 
B)  Each electron carrier alternates between being reduced and being oxidized. 
C)  ATP is generated at each step. 
D)  Energy of the electrons increases at each step. 
E)  Molecules in the chain give up some of their potential energy.

Question 2

If pyruvate oxidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle shown in Figure 7.1?

Accepted Answer

A)  There will be no change in the levels of oxaloacetate and citric acid. 
B)  Oxaloacetate will decrease and citric acid will accumulate. 
C)  Oxaloacetate will accumulate and citric acid will decrease. 
D)  Both oxaloacetate and citric acid will decrease. 
E)  Both oxaloacetate and citric acid will accumulate. 
A)  There will be no change in the levels of oxaloacetate and citric acid. 
B)  Oxaloacetate will decrease and citric acid will accumulate. 
C)  Oxaloacetate will accumulate and citric acid will decrease. 
D)  Both oxaloacetate and citric acid will decrease. 
E)  Both oxaloacetate and citric acid will accumulate.

Question 3

The ATP made during fermentation is generated by which of the following?

Accepted Answer

A)  the electron transport chain 
B)  substrate-level phosphorylation 
C)  chemiosmosis 
D)  oxidative phosphorylation 
E)  aerobic respiration 
A)  the electron transport chain 
B)  substrate-level phosphorylation 
C)  chemiosmosis 
D)  oxidative phosphorylation 
E)  aerobic respiration

Question 4

When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes

Accepted Answer

A)  dehydrogenated. 
B)  oxidized. 
C)  reduced. 
D)  redoxed. 
E)  hydrolyzed. 
A)  dehydrogenated. 
B)  oxidized. 
C)  reduced. 
D)  redoxed. 
E)  hydrolyzed.

Question 5

During aerobic respiration, H2O is formed. Where does the oxygen atom for the formation of the water come from?

Accepted Answer

A)  carbon dioxide (CO2) 
B)  glucose (C6H12O6) 
C)  molecular oxygen (O2) 
D)  pyruvate (C3H3O3-) 
E)  lactate (C3H5O3-) 
A)  carbon dioxide (CO2) 
B)  glucose (C6H12O6) 
C)  molecular oxygen (O2) 
D)  pyruvate (C3H3O3-) 
E)  lactate (C3H5O3-)

Question 6

The oxygen consumed during cellular respiration is involved directly in which process or event?

Accepted Answer

A)  glycolysis 
B)  accepting electrons at the end of the electron transport chain 
C)  the citric acid cycle 
D)  the oxidation of pyruvate to acetyl CoA 
E)  the phosphorylation of ADP to form ATP 
A)  glycolysis 
B)  accepting electrons at the end of the electron transport chain 
C)  the citric acid cycle 
D)  the oxidation of pyruvate to acetyl CoA 
E)  the phosphorylation of ADP to form ATP

Question 7

The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mol and the free energy for the reduction of NAD+ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed?

Accepted Answer

A)  Most of the free energy available from the oxidation of glucose is used in the production of ATP in glycolysis. 
B)  Glycolysis is a very inefficient reaction, with much of the energy of glucose released as heat. 
C)  Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis. 
D)  There is no CO2 or water produced as products of glycolysis. 
E)  Glycolysis consists of many enzymatic reactions, each of which extracts some energy from the glucose molecule. 
A)  Most of the free energy available from the oxidation of glucose is used in the production of ATP in glycolysis. 
B)  Glycolysis is a very inefficient reaction, with much of the energy of glucose released as heat. 
C)  Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis. 
D)  There is no CO2 or water produced as products of glycolysis. 
E)  Glycolysis consists of many enzymatic reactions, each of which extracts some energy from the glucose molecule.

Question 8

Where does glycolysis take place in eukaryotic cells?

Accepted Answer

A)  mitochondrial matrix 
B)  mitochondrial outer membrane 
C)  mitochondrial inner membrane 
D)  mitochondrial intermembrane space 
E)  cytosol 
A)  mitochondrial matrix 
B)  mitochondrial outer membrane 
C)  mitochondrial inner membrane 
D)  mitochondrial intermembrane space 
E)  cytosol

Question 9

During glycolysis, when each molecule of glucose is catabolized to two molecules of pyruvate, most of the potential energy contained in glucose is

Accepted Answer

A)  transferred to ADP, forming ATP. 
B)  transferred directly to ATP. 
C)  retained in the two pyruvates. 
D)  stored in the NADH produced. 
E)  used to phosphorylate fructose to form fructose 6-phosphate. 
A)  transferred to ADP, forming ATP. 
B)  transferred directly to ATP. 
C)  retained in the two pyruvates. 
D)  stored in the NADH produced. 
E)  used to phosphorylate fructose to form fructose 6-phosphate.

Question 10

An electron loses potential energy when it

Accepted Answer

A)  shifts to a less electronegative atom. 
B)  shifts to a more electronegative atom. 
C)  increases its kinetic energy. 
D)  increases its activity as an oxidizing agent. 
E)  moves further away from the nucleus of the atom. 
A)  shifts to a less electronegative atom. 
B)  shifts to a more electronegative atom. 
C)  increases its kinetic energy. 
D)  increases its activity as an oxidizing agent. 
E)  moves further away from the nucleus of the atom.

Question 11

In addition to ATP, what are the end products of glycolysis?

Accepted Answer

A)  CO2 and H2O 
B)  CO2 and pyruvate 
C)  NADH and pyruvate 
D)  CO2 and NADH 
E)  H2O, FADH2, and citrate 
A)  CO2 and H2O 
B)  CO2 and pyruvate 
C)  NADH and pyruvate 
D)  CO2 and NADH 
E)  H2O, FADH2, and citrate

Question 12

Yeast cells that have defective mitochondria incapable of respiration will be able to grow by catabolizing which of the following carbon sources for energy?

Accepted Answer

A)  glucose 
B)  proteins 
C)  fatty acids 
D)  glucose, proteins, and fatty acids 
E)  Such yeast cells will not be capable of catabolizing any food molecules, and will therefore die. 
A)  glucose 
B)  proteins 
C)  fatty acids 
D)  glucose, proteins, and fatty acids 
E)  Such yeast cells will not be capable of catabolizing any food molecules, and will therefore die.

Question 13

Which of the protein complexes labeled with Roman numerals in Figure 7.2 will transfer electrons to O2?

Accepted Answer

A)  complex I 
B)  complex II 
C)  complex III 
D)  complex IV 
E)  All of the complexes can transfer electrons to O2. 
A)  complex I 
B)  complex II 
C)  complex III 
D)  complex IV 
E)  All of the complexes can transfer electrons to O2.

Question 14

Which one of the following is formed by the removal of a carbon (as CO2) from a molecule of pyruvate?

Accepted Answer

A)  lactate 
B)  glyceraldehyde-3-phosphate 
C)  oxaloacetate 
D)  acetyl CoA 
E)  citrate 
A)  lactate 
B)  glyceraldehyde-3-phosphate 
C)  oxaloacetate 
D)  acetyl CoA 
E)  citrate

Question 15

What is proton-motive force?

Accepted Answer

A)  the force required to remove an electron from hydrogen 
B)  the force provided by a transmembrane hydrogen ion gradient 
C)  the force that moves hydrogen into the intermembrane space 
D)  the force that moves hydrogen into the mitochondrion 
E)  the force that moves hydrogen to NAD+ 
A)  the force required to remove an electron from hydrogen 
B)  the force provided by a transmembrane hydrogen ion gradient 
C)  the force that moves hydrogen into the intermembrane space 
D)  the force that moves hydrogen into the mitochondrion 
E)  the force that moves hydrogen to NAD+

Question 16

Which kind of metabolic poison would most directly interfere with glycolysis?

Accepted Answer

A)  an agent that reacts with oxygen and depletes its concentration in the cell 
B)  an agent that binds to pyruvate and inactivates it 
C)  an agent that closely mimics the structure of glucose but is not metabolized 
D)  an agent that reacts with NADH and oxidizes it to NAD+ 
E)  an agent that blocks the passage of electrons along the electron transport chain 
A)  an agent that reacts with oxygen and depletes its concentration in the cell 
B)  an agent that binds to pyruvate and inactivates it 
C)  an agent that closely mimics the structure of glucose but is not metabolized 
D)  an agent that reacts with NADH and oxidizes it to NAD+ 
E)  an agent that blocks the passage of electrons along the electron transport chain

Question 17

You have a friend who lost 7 kg (about 15 pounds) of fat on a regimen of strict diet and exercise. How did the fat leave her body?

Accepted Answer

A)  It was released as CO2 and H2O. 
B)  It was converted to heat and then released. 
C)  It was converted to ATP, which weighs much less than fat. 
D)  It was broken down to amino acids and eliminated from the body. 
E)  It was converted to urine and eliminated from the body. 
A)  It was released as CO2 and H2O. 
B)  It was converted to heat and then released. 
C)  It was converted to ATP, which weighs much less than fat. 
D)  It was broken down to amino acids and eliminated from the body. 
E)  It was converted to urine and eliminated from the body.

Question 18

What fraction of the carbon dioxide exhaled by animals is generated by the reactions of the citric acid cycle, if glucose is the sole energy source?

Accepted Answer

A)  1/6 
B)  1/3 
C)  1/2 
D)  2/3 
E)  all of it 
A)  1/6 
B)  1/3 
C)  1/2 
D)  2/3 
E)  all of it

Question 19

When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes

Accepted Answer

A)  hydrolyzed. 
B)  hydrogenated. 
C)  oxidized. 
D)  reduced. 
E)  an oxidizing agent. 
A)  hydrolyzed. 
B)  hydrogenated. 
C)  oxidized. 
D)  reduced. 
E)  an oxidizing agent.

Question 20

Figure 7.2
-Figure 7.2 shows the electron transport chain. Which of the following is the combination of substances that is initially added to the chain?

Accepted Answer

A)  oxygen, carbon dioxide, and water 
B)  NAD+, FAD, and electrons 
C)  NADH, FADH2, and protons 
D)  NADH, FADH2, and O2 
E)  oxygen and protons 
A)  oxygen, carbon dioxide, and water 
B)  NAD+, FAD, and electrons 
C)  NADH, FADH2, and protons 
D)  NADH, FADH2, and O2 
E)  oxygen and protons

Exam 7: Cellular Respiration and Fermentation

Which of the following most accurately describes what is happening along the electron transport chain in Figure 7.2?

If pyruvate oxidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle shown in Figure 7.1?

The ATP made during fermentation is generated by which of the following?

When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes

During aerobic respiration, H2O is formed. Where does the oxygen atom for the formation of the water come from?

The oxygen consumed during cellular respiration is involved directly in which process or event?

The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mol and the free energy for the reduction of NAD+ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed?

Where does glycolysis take place in eukaryotic cells?

During glycolysis, when each molecule of glucose is catabolized to two molecules of pyruvate, most of the potential energy contained in glucose is

An electron loses potential energy when it

In addition to ATP, what are the end products of glycolysis?

Yeast cells that have defective mitochondria incapable of respiration will be able to grow by catabolizing which of the following carbon sources for energy?

Which of the protein complexes labeled with Roman numerals in Figure 7.2 will transfer electrons to O2?

Which one of the following is formed by the removal of a carbon (as CO2) from a molecule of pyruvate?

What is proton-motive force?

Which kind of metabolic poison would most directly interfere with glycolysis?

You have a friend who lost 7 kg (about 15 pounds) of fat on a regimen of strict diet and exercise. How did the fat leave her body?

What fraction of the carbon dioxide exhaled by animals is generated by the reactions of the citric acid cycle, if glucose is the sole energy source?

When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes

Figure 7.2 -Figure 7.2 shows the electron transport chain. Which of the following is the combination of substances that is initially added to the chain?

Introduction: Evolution and the Foundations of Biology

The Chemical Context of Life

Carbon and the Molecular Diversity of Life

A Tour of the Cell

Membrane Transport and Cell Signaling

An Introduction to Metabolism

Photosynthesis

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Development, Stem Cells, and Cancer

Viruses

Genomes and Their Evolution

Descent With Modification

Phylogeny

The Evolution of Populations

The Origin of Species

Broad Patterns of Evolution

Early Life and the Diversification of Prokaryotes

The Origin and Diversification of Eukaryotes

The Colonization of Land by Plants and Fungi

The Rise of Animal Diversity

Plant Structure and Growth

Resource Acquisition, Nutrition, and Transport in Vascular Plants

Reproduction and Domestication of Flowering Plants

Plant Responses to Internal and External Signals

Homeostasis and Endocrine Signaling

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Reproduction and Development

Neurons, Synapses, and Signaling

Nervous and Sensory Systems

Motor Mechanisms and Behavior

Population Ecology and the Distribution of Organisms

Species Interactions

Ecosystems and Energy

Global Ecology and Conservation Biology

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