Question 1

Glycolysis is active when cellular energy levels are ________; the regulatory enzyme, phosphofructokinase, is ________ by ATP.

Accepted Answer

A)  low; activated 
B)  low; inhibited 
C)  high; activated 
D)  high; inhibited 
A)  low; activated 
B)  low; inhibited 
C)  high; activated 
D)  high; inhibited B

Question 2

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of ________.

Accepted Answer

A)  active transport 
B)  an endergonic reaction coupled to an exergonic reaction 
C)  a reaction with a positive ΔG 
D)  osmosis 
E)  allosteric regulation 
A)  active transport 
B)  an endergonic reaction coupled to an exergonic reaction 
C)  a reaction with a positive ΔG 
D)  osmosis 
E)  allosteric regulation B

Question 3

Fatty acids usually have an even number of carbons in their structures. They are catabolized by a process called beta-oxidation. The end products of the metabolic pathway are acetyl groups
Of acetyl-CoA molecules. These acetyl groups ________.

Accepted Answer

A)  directly enter the electron transport chain 
B)  directly enter the energy-yielding stages of glycolysis 
C)  are directly decarboxylated by pyruvate dehydrogenase 
D)  directly enter the citric acid cycle 
A)  directly enter the electron transport chain 
B)  directly enter the energy-yielding stages of glycolysis 
C)  are directly decarboxylated by pyruvate dehydrogenase 
D)  directly enter the citric acid cycle D

Question 4

Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis?

Accepted Answer

A)  0 percent 
B)  2 percent 
C)  10 percent 
D)  38 percent 
E)  100 percent 
A)  0 percent 
B)  2 percent 
C)  10 percent 
D)  38 percent 
E)  100 percent

Question 5

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, therefore, will 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, therefore, will die.

Question 6

Inside an active mitochondrion, most electrons follow which pathway?

Accepted Answer

A)  glycolysis → NADH → oxidative phosphorylation → ATP → oxygen 
B)  citric acid cycle → FADH2 → electron transport chain → ATP 
C)  electron transport chain → citric acid cycle → ATP → oxygen 
D)  pyruvate → citric acid cycle → ATP → NADH → oxygen 
E)  citric acid cycle → NADH → electron transport chain → oxygen 
A)  glycolysis → NADH → oxidative phosphorylation → ATP → oxygen 
B)  citric acid cycle → FADH2 → electron transport chain → ATP 
C)  electron transport chain → citric acid cycle → ATP → oxygen 
D)  pyruvate → citric acid cycle → ATP → NADH → oxygen 
E)  citric acid cycle → NADH → electron transport chain → oxygen

Question 7

A mutation in yeast makes it unable to convert pyruvate to ethanol. How will this mutation affect these yeast cells? The mutant yeast cells will ________.

Accepted Answer

A)  be unable to grow anaerobically 
B)  grow anaerobically only when given glucose 
C)  be unable to metabolize glucose 
D)  die because they cannot regenerate NAD+ from NAD 
E)  metabolize only fatty acids 
A)  be unable to grow anaerobically 
B)  grow anaerobically only when given glucose 
C)  be unable to metabolize glucose 
D)  die because they cannot regenerate NAD+ from NAD 
E)  metabolize only fatty acids

Question 8

Energy released by the electron transport chain is used to pump H+ into which location in eukaryotic cells?

Accepted Answer

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

Question 9

In glycolysis, for each molecule of glucose oxidized to pyruvate ________.

Accepted Answer

A)  two molecules of ATP are used and two molecules of ATP are produced. 
B)  two molecules of ATP are used and four molecules of ATP are produced. 
C)  four molecules of ATP are used and two molecules of ATP are produced. 
D)  two molecules of ATP are used and six molecules of ATP are produced. 
E)  six molecules of ATP are used and six molecules of ATP are produced. 
A)  two molecules of ATP are used and two molecules of ATP are produced. 
B)  two molecules of ATP are used and four molecules of ATP are produced. 
C)  four molecules of ATP are used and two molecules of ATP are produced. 
D)  two molecules of ATP are used and six molecules of ATP are produced. 
E)  six molecules of ATP are used and six molecules of ATP are produced.

Question 10

Even though plants cells photosynthesize, they still use their mitochondria for oxidation of pyruvate. This will occur in ________.

Accepted Answer

A)  photosynthetic cells in the light, while photosynthesis occurs concurrently 
B)  nonphotosynthesizing cells only 
C)  cells that are storing glucose only 
D)  all cells all the time 
E)  photosynthesizing cells in the light and in other tissues in the dark 
A)  photosynthetic cells in the light, while photosynthesis occurs concurrently 
B)  nonphotosynthesizing cells only 
C)  cells that are storing glucose only 
D)  all cells all the time 
E)  photosynthesizing cells in the light and in other tissues in the dark

Question 11

Use the accompanying figure to answer the question(s) below.  
-If pyruvate oxidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle shown in the accompanying figure?

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 12

Which of the listed statements describes the results of the following reaction?
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy

Accepted Answer

A)  C6H12O6 is oxidized and O2 is reduced. 
B)  O2 is oxidized and H2O is reduced. 
C)  CO2 is reduced and O2 is oxidized. 
D)  C6H12O6 is reduced and CO2 is oxidized. 
E)  O2 is reduced and CO2 is oxidized. 
A)  C6H12O6 is oxidized and O2 is reduced. 
B)  O2 is oxidized and H2O is reduced. 
C)  CO2 is reduced and O2 is oxidized. 
D)  C6H12O6 is reduced and CO2 is oxidized. 
E)  O2 is reduced and CO2 is oxidized.

Question 13

Why are fermentation reactions important for cells?

Accepted Answer

A)  They produce alcohol, which enhances the permeability of their mitochondrial membranes to proton translocation. 
B)  They regenerate NAD+ so that glycolysis can continue to operate. 
C)  They allow the cell to conserve oxygen for the citric acid cycle. 
D)  They generate oxygen. 
A)  They produce alcohol, which enhances the permeability of their mitochondrial membranes to proton translocation. 
B)  They regenerate NAD+ so that glycolysis can continue to operate. 
C)  They allow the cell to conserve oxygen for the citric acid cycle. 
D)  They generate oxygen.

Question 14

During cellular respiration, acetyl CoA accumulates in which location?

Accepted Answer

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

Question 15

An organism is discovered that thrives in both the presence and absence of oxygen in the air. Curiously, the consumption of sugar increases as oxygen is removed from the organism's environment, even though the organism does not gain much weight. This organism ________.

Accepted Answer

A)  must use a molecule other than oxygen to accept electrons from the electron transport chain 
B)  is a normal eukaryotic organism 
C)  is photosynthetic 
D)  is an anaerobic organism 
E)  is a facultative anaerobe 
A)  must use a molecule other than oxygen to accept electrons from the electron transport chain 
B)  is a normal eukaryotic organism 
C)  is photosynthetic 
D)  is an anaerobic organism 
E)  is a facultative anaerobe

Question 16

Why might adding inorganic phosphate to a reaction mixture where glycolysis is rapidly proceeding help sustain the metabolic pathway?

Accepted Answer

A)  It would increase the amount of glucose available for catabolism. 
B)  It would increase the oxygen supply available for aerobic respiration because each phosphate group contains four oxygen atoms as constituents. 
C)  The metabolic intermediates of glycolysis are phosphorylated. 
D)  It increases the energy level of the electrons that are transferred to the electron transport chain where ATP is produced. 
A)  It would increase the amount of glucose available for catabolism. 
B)  It would increase the oxygen supply available for aerobic respiration because each phosphate group contains four oxygen atoms as constituents. 
C)  The metabolic intermediates of glycolysis are phosphorylated. 
D)  It increases the energy level of the electrons that are transferred to the electron transport chain where ATP is produced.

Question 17

Which metabolic pathway is common to both cellular respiration and fermentation?

Accepted Answer

A)  the oxidation of pyruvate to acetyl CoA 
B)  the citric acid cycle 
C)  oxidative phosphorylation 
D)  glycolysis 
E)  chemiosmosis 
A)  the oxidation of pyruvate to acetyl CoA 
B)  the citric acid cycle 
C)  oxidative phosphorylation 
D)  glycolysis 
E)  chemiosmosis

Question 18

Which electron carrier(s) function in the citric acid cycle?

Accepted Answer

A)  NAD+ only 
B)  NADH and FADH2 
C)  the electron transport chain 
D)  ADP and ATP 
A)  NAD+ only 
B)  NADH and FADH2 
C)  the electron transport chain 
D)  ADP and ATP

Question 19

Starting with one molecule of glucose, the energy-containing products of glycolysis are ________.

Accepted Answer

A)  2 NAD+, 2 pyruvate, and 2 ATP 
B)  2 NADH, 2 pyruvate, and 2 ATP 
C)  2 FADH2, 2 pyruvate, and 4 ATP 
D)  6 CO2, 2 pyruvate, and 2 ATP 
E)  6 CO2, 2 pyruvate, and 30 ATP 
A)  2 NAD+, 2 pyruvate, and 2 ATP 
B)  2 NADH, 2 pyruvate, and 2 ATP 
C)  2 FADH2, 2 pyruvate, and 4 ATP 
D)  6 CO2, 2 pyruvate, and 2 ATP 
E)  6 CO2, 2 pyruvate, and 30 ATP

Question 20

The constituents of the electron transport chain have similar capabilities, with the exception of ubiquinone (coenzyme Q). What is different about ubiquinone?

Accepted Answer

A)  Ubiquinone is a protein that begins the electron transport chain, so it accepts the highest-energy electrons. 
B)  Ubiquinone is a protein that serves as a regulator of the rate of redox reactions in the electron transport chain. 
C)  Ubiquinone is a protein that is a constituent of all cells, prokaryotic or eukaryotic; hence its name, originating from "ubiquitous." 
D)  Ubiquinone is not a protein, is lipid soluble, and can move through the inner mitochondrial membrane. 
A)  Ubiquinone is a protein that begins the electron transport chain, so it accepts the highest-energy electrons. 
B)  Ubiquinone is a protein that serves as a regulator of the rate of redox reactions in the electron transport chain. 
C)  Ubiquinone is a protein that is a constituent of all cells, prokaryotic or eukaryotic; hence its name, originating from "ubiquitous." 
D)  Ubiquinone is not a protein, is lipid soluble, and can move through the inner mitochondrial membrane.

Exam 9: Cellular Respiration and Fermentation

Glycolysis is active when cellular energy levels are ________; the regulatory enzyme, phosphofructokinase, is ________ by ATP.

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of ________.

Fatty acids usually have an even number of carbons in their structures. They are catabolized by a process called beta-oxidation. The end products of the metabolic pathway are acetyl groups Of acetyl-CoA molecules. These acetyl groups ________.

Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions 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?

Inside an active mitochondrion, most electrons follow which pathway?

A mutation in yeast makes it unable to convert pyruvate to ethanol. How will this mutation affect these yeast cells? The mutant yeast cells will ________.

Energy released by the electron transport chain is used to pump H+ into which location in eukaryotic cells?

In glycolysis, for each molecule of glucose oxidized to pyruvate ________.

Even though plants cells photosynthesize, they still use their mitochondria for oxidation of pyruvate. This will occur in ________.

Use the accompanying figure to answer the question(s) below. -If pyruvate oxidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle shown in the accompanying figure?

Which of the listed statements describes the results of the following reaction? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy

Why are fermentation reactions important for cells?

During cellular respiration, acetyl CoA accumulates in which location?

An organism is discovered that thrives in both the presence and absence of oxygen in the air. Curiously, the consumption of sugar increases as oxygen is removed from the organism's environment, even though the organism does not gain much weight. This organism ________.

Why might adding inorganic phosphate to a reaction mixture where glycolysis is rapidly proceeding help sustain the metabolic pathway?

Which metabolic pathway is common to both cellular respiration and fermentation?

Which electron carrier(s) function in the citric acid cycle?

Starting with one molecule of glucose, the energy-containing products of glycolysis are ________.

The constituents of the electron transport chain have similar capabilities, with the exception of ubiquinone (coenzyme Q). What is different about ubiquinone?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Ecosystems and Global Ecology

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes: an Introduction to Metabolism

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Genes, Development, and Evolution

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, Signals, and Responses

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Biodiversity and Conservation Biology

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Glycolysis is active when cellular energy levels are ; the regulatory enzyme, phosphofructokinase, is by ATP.