Question 1

Many types of cancer cells have been detected to secrete significant levels of lactate.Do you think these cells are likely undergoing beta-oxidation?

Accepted Answer

A)  Yes, because beta-oxidation can generate intermediates that would lead to the production of lactate.
B)  No, because if lactate is being produced, the cell is not likely making use of the pathways needed to make use of the products of beta-oxidation.
C)  Yes, because lactate stimulates beta-oxidation.
D)  No, because lactate is consumed in beta-oxidationE) A) and B)
F) A) and C)

Question 2

As electrons move along the electron transport chain, they lose potential energy.How is the energy that is released used by the cell?

Accepted Answer

A)  The energy is used to transport protons against their concentration gradient
B)  The energy is used to pump electrons along the electron transport chain
C)  The energy is converted directly into ATP
D)  The energy is used to pump NAD+ into the cytoplasm so it can be used in glycolysisE) B) and D)
F) A) and D)

Question 3

If ATP synthase had a mutation in the F1 complex portion of the protein, which function of ATP synthase would most likely be affected?

Accepted Answer

A)  The rotation of the rotor
B)  The flow of protons through the channel
C)  The conversion of ADP and Pi to ATP
D)  The insertion of the enzyme into the membraneE) All of the above
F) A) and B)

Question 4

Aerobic respiration involves the transfer of many electrons from glucose to electron carriers such as NAD+ over a series of multiple steps.Ultimately though, it is the reaction of glucose with oxygen to generate carbon dioxide, water and energy.Why doesn't glucose react directly with oxygen in cells?

Accepted Answer

A)  Oxygen cannot accept electrons, and thus an electron carrier like NAD+ is needed.
B)  Oxygen and glucose are localized in different subcellular compartments.
C)  The direct reaction of oxygen with glucose would be extremely destructive to cells.
D)  The reaction of oxygen with glucose is not spontaneous.E) A) and B)
F) A) and C)

Question 5

In glycolysis, a major portion of the energy remains in the final product, which is called

Accepted Answer

A)  glucose.
B)  citrate.
C)  glyceraldehyde 3-phosphate (G3P) .
D)  pyruvate.E) A) and D)
F) A) and B)

Question 6

A human cell has a mutation in the gene that encodes the enzyme that generates lactate from pyruvate, rendering that enzyme completely non-functional.Assuming that there is ample glucose present, how would this cell generate energy in the presence of oxygen?

Accepted Answer

A)  Glycolysis coupled with ethanol fermentation
B)  Aerobic respiration
C)  Primarily through the break down of proteins into amino acids
D)  This cell would have no way to generate energy under these conditions because it cannot carry out the reactions needed for glycolysisE) C) and D)
F) A) and C)

Question 7

In animals that take in oxygen from their environment, glucose is broken down into carbon dioxide and water in a process called

Accepted Answer

A)  anaerobic respiration.
B)  organic compound respiration.
C)  glucose respiration.
D)  aerobic respiration.E) All of the above
F) B) and C)

Question 8

Pyruvate oxidation in eukaryotic cells occurs in the ________.

Accepted Answer

A)  cytoplasm
B)  nucleus
C)  Golgi body
D)  mitochondriaE) None of the above
F) B) and C)

Question 9

Organisms that can manufacture their own chemical energy are called ____________.

Accepted Answer

A)  autotrophs
B)  heterotrophs
C)  oligotrophs
D)  chemotrophsE) B) and C)
F) All of the above

Question 10

In the reaction: C4H6O4 + FAD  →\rightarrow→ C4H4O4 + FADH2, what type of reaction took place to remove the protons from C4H6O4?

Accepted Answer

A)  Decarboxylation
B)  Reduction
C)  Dehydrogenation
D)  Oxidation E) C) and D)
F) None of the above

Question 11

If you take into account the amount of ATP generated by ATP synthase per molecule of NADH and per molecule of FADH2 produced, and the number of ATP molecules produced by substrate-level phosphorylation, what is the predicted energy yield of the Krebs cycle, per molecule of glucose in eukaryotic cells?

Accepted Answer

A)  18 ATP
B)  2 ATP
C)  10 ATP
D)  20 ATPE) A) and B)
F) A) and C)

Question 12

Phosphofructokinase is regulated by a number of factors, including high levels of ATP.Why is this enzyme regulated by ATP levels?

Accepted Answer

A)  If ATP levels are high, this provides a mechanism to directly inhibit the Krebs cycle, thus preventing further generation of NADH, FADH2 and ATP molecules that are not needed.
B)  If ATP levels are high, it is important to directly inhibit the reaction that commits the substrate to glycolysis to allow the substrate to be available for other reactions, since the cell has ample energy.
C)  If ATP levels are high, it is important to inhibit ATP synthase, and phosphofructokinase directly inhibits ATP synthase.
D)  If ATP levels are high, this provides a mechanism to directly inhibit the electron transport chain, thus preventing the formation of a proton gradient in the intermembrane space of mitochondria.E) A) and C)
F) A) and B)

Question 13

What is common to all of the oxidation reactions in the Krebs cycle?

Accepted Answer

A)  They all lead to the generation of NADH.
B)  They are all decarboxylation reactions.
C)  They are all characterized by a loss of electrons from an organic molecule coupled to the reduction of an electron acceptor.
D)  They all lead to substrate-level phosphorylation of ADP to generate ATP. While all of the oxidation reactions are characterized by the donation of electrons from an organic molecule to an electron acceptor, they are not all decarboxylation reactions, nor do they all involve the generation of NADH.The third oxidation reaction is not a decarboxylation reaction, and involves the generation of FADH2.None of the oxidation reactions directly induce substrate-level phosphorylation of ADP.E) C) and D)
F) A) and B)

Question 14

A biochemist wants to control the initial substrate-level phosphorylation that occurs in the tracheal cells of grasshoppers once glucose has crossed the plasma membrane.He has access to the following inhibitors: Rotenone - an electron transport chain inhibitor, Oligomycin - an ATP synthase inhibitor, and TLN-232, an inhibitor of glycolysis.Which inhibitor should he use to slow down initial substrate-level phosphorylation that occurs once glucose has crossed the plasma membrane?

Accepted Answer

A)  Rotenone
B)  Oligomycin
C)  TLN-232
D)  None of these inhibitors would be effective in preventing substrate-level phosphorylationE) C) and D)
F) B) and D)

Question 15

The Krebs cycle occurs in the mitochondria.There are nine biochemical reactions involved in the Krebs cycle, and they are highly ordered.Select the correct order.(Note: These are abbreviated and do not show NAD, ADP, ATP, or FAD.)

Accepted Answer

A)  acetyl-CoA joins the Kreb cycle and unites with oxaloacetate  →\rightarrow→ forming citrate  →\rightarrow→ which forms beta-ketoglutarate  →\rightarrow→  which forms succinyl-CoA  →\rightarrow→  which forms succinate  →\rightarrow→ which forms fumarate  →\rightarrow→  which forms malate  →\rightarrow→ which forms oxaloacetate
B)  acetyl-CoA joins the Kreb cycle and unites with oxaloacetate  →\rightarrow→ forming citrate  →\rightarrow→ which forms alpha-ketoglutarate  →\rightarrow→  which forms succinyl-CoA  →\rightarrow→  which forms succinate  →\rightarrow→  which forms malate  →\rightarrow→  which forms fumarate  →\rightarrow→  which forms oxaloacetate
C)  acetyl-CoA joins the Kreb cycle and unites with oxaloacetate  →\rightarrow→ which forms alpha-ketoglutarate  →\rightarrow→  forming citrate  →\rightarrow→  which forms succinyl-CoA  →\rightarrow→  which forms succinate  →\rightarrow→ which forms fumarate  →\rightarrow→ which forms malate  →\rightarrow→  which forms oxaloacetate
D)  acetyl-CoA joins the Kreb cycle and unites with oxaloacetate  →\rightarrow→ forming citrate  →\rightarrow→ which forms alpha-ketoglutarate  →\rightarrow→  which forms succinyl-CoA  →\rightarrow→  which forms succinate  →\rightarrow→  which forms fumarate  →\rightarrow→  which forms malate  →\rightarrow→  which forms oxaloacetate E) B) and D)
F) B) and C)

Question 16

During what step of glycolysis are two ATP molecules required?

Accepted Answer

A)  Cleavage and rearrangement
B)  Glucose priming
C)  Oxidation
D)  Pyruvate formationE) A) and D)
F) B) and C)

Question 17

When substrate-level phosphorylation occurs, it means that:

Accepted Answer

A)  NAD+ is converted into NADH.
B)  ATP is converted into ADP plus a phosphate group.
C)  ADP is converted into ATP by the addition of a phosphate group.
D)  NADH is converted into NAD+ plus a proton.E) A) and C)
F) All of the above

Question 18

If you take into account the amount of ATP generated by ATP synthase per molecule of NADH produced in aerobic respiration, the net number of ATP molecules produced by substrate-level phosphorylation, and the fact that NADH molecules produced in the cytoplasm have to be transported into the mitochondria, what is the predicted energy yield of glycolysis in eukaryotic cells?

Accepted Answer

A)  2 ATP
B)  5 ATP
C)  7 ATP
D)  32 ATPE) A) and D)
F) None of the above

Question 19

What stage of cellular respiration can occur in human cells with or without oxygen present?

Accepted Answer

A)  The Krebs cycle
B)  Glycolysis
C)  The electron transport chain
D)  Pyruvate oxidationE) A) and D)
F) None of the above

Question 20

This process is common to all living cells:

Accepted Answer

A)  Glycolysis
B)  Alcohol fermentation
C)  The Krebs cycle
D)  Electron transport chain reactionsE) All of the above
F) A) and B)

Exam 7: How Cells Harvest Energy

Organisms that can manufacture their own chemical energy are called ____________.

Correct Answer
verified

In the reaction: C₄H₆O₄ + FAD $\rightarrow$ C₄H₄O₄ + FADH₂, what type of reaction took place to remove the protons from C₄H₆O₄?

Correct Answer
verified

As electrons move along the electron transport chain, they lose potential energy.How is the energy that is released used by the cell?

Correct Answer
verified

If ATP synthase had a mutation in the F₁ complex portion of the protein, which function of ATP synthase would most likely be affected?

Correct Answer
verified

A human cell has a mutation in the gene that encodes the enzyme that generates lactate from pyruvate, rendering that enzyme completely non-functional.Assuming that there is ample glucose present, how would this cell generate energy in the presence of oxygen?

Correct Answer
verified

What is common to all of the oxidation reactions in the Krebs cycle?

Correct Answer
verified

In animals that take in oxygen from their environment, glucose is broken down into carbon dioxide and water in a process called

Correct Answer
verified

Correct Answer
verified

When substrate-level phosphorylation occurs, it means that:

Correct Answer
verified

What stage of cellular respiration can occur in human cells with or without oxygen present?

Correct Answer
verified

Pyruvate oxidation in eukaryotic cells occurs in the ________.

Correct Answer
verified

The Krebs cycle occurs in the mitochondria.There are nine biochemical reactions involved in the Krebs cycle, and they are highly ordered.Select the correct order.(Note: These are abbreviated and do not show NAD, ADP, ATP, or FAD.)

Correct Answer
verified

Correct Answer
verified

Phosphofructokinase is regulated by a number of factors, including high levels of ATP.Why is this enzyme regulated by ATP levels?

Correct Answer
verified

Many types of cancer cells have been detected to secrete significant levels of lactate.Do you think these cells are likely undergoing beta-oxidation?

Correct Answer
verified

This process is common to all living cells:

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

In glycolysis, a major portion of the energy remains in the final product, which is called

Correct Answer
verified

During what step of glycolysis are two ATP molecules required?

Correct Answer
verified

Exam 7: How Cells Harvest Energy

Organisms that can manufacture their own chemical energy are called ____________.

Correct AnswerverifiedShow Answer

In the reaction: C4H6O4 + FAD →\rightarrow→ C4H4O4 + FADH2, what type of reaction took place to remove the protons from C4H6O4?

Correct AnswerverifiedShow Answer

As electrons move along the electron transport chain, they lose potential energy.How is the energy that is released used by the cell?

Correct AnswerverifiedShow Answer

If ATP synthase had a mutation in the F1 complex portion of the protein, which function of ATP synthase would most likely be affected?

Correct AnswerverifiedShow Answer

A human cell has a mutation in the gene that encodes the enzyme that generates lactate from pyruvate, rendering that enzyme completely non-functional.Assuming that there is ample glucose present, how would this cell generate energy in the presence of oxygen?

Correct AnswerverifiedShow Answer

What is common to all of the oxidation reactions in the Krebs cycle?

Correct AnswerverifiedShow Answer

In animals that take in oxygen from their environment, glucose is broken down into carbon dioxide and water in a process called

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

When substrate-level phosphorylation occurs, it means that:

Correct AnswerverifiedShow Answer

What stage of cellular respiration can occur in human cells with or without oxygen present?

Correct AnswerverifiedShow Answer

Pyruvate oxidation in eukaryotic cells occurs in the ________.

Correct AnswerverifiedShow Answer

The Krebs cycle occurs in the mitochondria.There are nine biochemical reactions involved in the Krebs cycle, and they are highly ordered.Select the correct order.(Note: These are abbreviated and do not show NAD, ADP, ATP, or FAD.)

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Phosphofructokinase is regulated by a number of factors, including high levels of ATP.Why is this enzyme regulated by ATP levels?

Correct AnswerverifiedShow Answer

Many types of cancer cells have been detected to secrete significant levels of lactate.Do you think these cells are likely undergoing beta-oxidation?

Correct AnswerverifiedShow Answer

This process is common to all living cells:

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

In glycolysis, a major portion of the energy remains in the final product, which is called

Correct AnswerverifiedShow Answer

During what step of glycolysis are two ATP molecules required?

Correct AnswerverifiedShow Answer

Correct Answer
verified

In the reaction: C₄H₆O₄ + FAD $\rightarrow$ C₄H₄O₄ + FADH₂, what type of reaction took place to remove the protons from C₄H₆O₄?

Correct Answer
verified

Correct Answer
verified

If ATP synthase had a mutation in the F₁ complex portion of the protein, which function of ATP synthase would most likely be affected?

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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