Question 1

Use Figure 8.3 to answer the following questions.
 
-In coupled reactions, in which direction would the endergonic reaction be driven relative to the clockwise direction of the ATP reaction above and shown in the figure?

Accepted Answer

A)  from left to right at the top of the figure
B)  under the symbol for energy doing cellular work in the figure
C)  from right to left at the bottom of the figure
D)  it would be shown separately after the figure
E)  it would be shown in a clockwise direction at the top of the figureF) B) and C)
G) C) and D)

Question 2

Most cells cannot harness heat to perform work because

Accepted Answer

A)  heat is not a form of energy.
B)  cells do not have much heat; they are relatively cool.
C)  temperature is usually uniform throughout a cell.
D)  heat can never be used to do work.
E)  heat denatures enzymes.F) A) and D)
G) None of the above

Question 3

Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as a(n)

Accepted Answer

A)  competitive inhibitor of the enzyme.
B)  noncompetitive inhibitor of the enzyme.
C)  allosteric activator of the enzyme.
D)  cofactor necessary for enzyme activity.
E)  coenzyme derived from a vitamin.F) B) and D)
G) A) and B)

Question 4

Some bacteria are metabolically active in hot springs because

Accepted Answer

A)  they are able to maintain a cooler internal temperature.
B)  high temperatures make catalysis unnecessary.
C)  their enzymes have high optimal temperatures.
D)  their enzymes are completely insensitive to temperature.
E)  they use molecules other than proteins or RNAs as their main catalysts.F) B) and C)
G) All of the above

Question 5

Which of the following is most similar in structure to ATP?

Accepted Answer

A)  an anabolic steroid
B)  a DNA helix
C)  an RNA nucleotide
D)  an amino acid with three phosphate groups attached
E)  a phospholipidF) A) and E)
G) C) and D)

Question 6

The following questions are based on the reaction A + B → C + D shown in Figure 8.2.

-Which of the following bests describes the reaction?

Accepted Answer

A)  negative △G, spontaneous
B)  positive △G, nonspontaneous
C)  positive △G, exergonic
D)  negative △G, endergonic
E)  △G of zero, chemical equilibriumF) B) and C)
G) C) and E)

Question 7

The following questions are based on the reaction A + B → C + D shown in Figure 8.2.

-Which of the following represents the △G of the reaction?

Accepted Answer

A)  a
B)  b
C)  c
D)  d
E)  eF) All of the above
G) A) and E)

Question 8

Which of the following statements is True concerning catabolic pathways?

Accepted Answer

A)  They combine molecules into more energy-rich molecules.
B)  They are usually coupled with anabolic pathways to which they supply energy in the form of ATP.
C)  They are endergonic.
D)  They are spontaneous and do not need enzyme catalysis.
E)  They build up complex molecules such as protein from simpler compounds.F) A) and B)
G) A) and C)

Question 9

Use the following information to answer the following questions.
Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid.
-Based on this information, which of the following is correct?

Accepted Answer

A)  Succinate dehydrogenase is the enzyme, and fumarate is the substrate.
B)  Succinate dehydrogenase is the enzyme, and malonic acid is the substrate.
C)  Succinate is the substrate, and fumarate is the product.
D)  Fumarate is the product, and malonic acid is a noncompetitive inhibitor.
E)  Malonic acid is the product, and fumarate is a competitive inhibitor.F) C) and D)
G) A) and B)

Question 10

Why is ATP an important molecule in metabolism?

Accepted Answer

A)  Its hydrolysis provides an input of free energy for exergonic reactions.
B)  It provides energy coupling between exergonic and endergonic reactions.
C)  Its terminal phosphate group contains a strong covalent bond that when hydrolyzed releases free energy.
D)  Its terminal phosphate bond has higher energy than the other two.
E)  A, B, C, and DF) C) and E)
G) C) and D)

Question 11

When 10,000 molecules of ATP are hydrolyzed to ADP and Pi in a test tube, about twice as much heat is liberated as when a cell hydrolyzes the same amount of ATP. Which of the following is the best explanation for this observation?

Accepted Answer

A)  Cells are open systems, but a test tube is a closed system.
B)  Cells are less efficient at heat production than nonliving systems.
C)  The hydrolysis of ATP in a cell produces different chemical products than does the reaction in a test tube.
D)  The reaction in cells must be catalyzed by enzymes, but the reaction in a test tube does not need enzymes.
E)  Reactant and product concentrations are not the sameF) C) and E)
G) A) and B)

Question 12

The following questions are based on the reaction A + B → C + D shown in Figure 8.2.

-How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?

Accepted Answer

A)  by binding at the active site of the enzyme
B)  by changing the shape of a reactant
C)  by changing the free energy change of the reaction
D)  by acting as a coenzyme for the reaction
E)  by decreasing the activation energy of the reactionF) A) and D)
G) C) and D)

Question 13

The following questions are based on the reaction A + B → C + D shown in Figure 8.2.

-Which of the following represents the activation energy required for a noncatalyzed reaction?

Accepted Answer

A)  a
B)  b
C)  c
D)  d
E)  eF) C) and D)
G) A) and C)

Question 14

When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any) in the cell?

Accepted Answer

A)  It is released as an excretory waste.
B)  It can only be used to regenerate more ATP.
C)  It can be added to water and excreted as a liquid.
D)  It can be added to other molecules in order to activate them.
E)  It can enter the nucleus to affect gene expression.F) B) and E)
G) A) and B)

Question 15

Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity?

Accepted Answer

A)  cessation of all enzyme formation
B)  compartmentalization of enzymes into defined organelles
C)  exporting enzymes out of the cell
D)  connecting enzymes into large aggregates
E)  hydrophobic interactionsF) B) and E)
G) All of the above

Question 16

Refer to Figure 8.1 to answer the following questions.
 
-Which curve was most likely generated from an enzyme that requires a cofactor?

Accepted Answer

A)  curve 1
B)  curve 2
C)  curve 4
D)  curve 5
E)  It is not possible to determine whether an enzyme requires a cofactor from these data.F) A) and B)
G) B) and E)

Question 17

Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?

Accepted Answer

A)  denaturization of the enzyme
B)  allosteric inhibition
C)  competitive inhibition
D)  saturation of the enzyme activity
E)  insufficient cofactorsF) C) and D)
G) B) and D)

Question 18

Which of the following types of reactions would decrease the entropy within a cell?

Accepted Answer

A)  dehydration reactions
B)  hydrolysis
C)  respiration
D)  digestion
E)  catabolismF) B) and E)
G) A) and B)

Question 19

If an enzyme solution is saturated with substrate, the most effective way to obtain a faster yield of products is to

Accepted Answer

A)  add more of the enzyme.
B)  heat the solution to 90°C.
C)  add more substrate.
D)  add an allosteric inhibitor.
E)  add a noncompetitive inhibitor.F) A) and B)
G) A) and C)

Question 20

When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows:

Accepted Answer

A)  +△G, +△H, +△S
B)  +△G, +△H, -△S
C)  +△G, -△H, -△S
D)  -△G, +△H, +△S
E)  -△G, -△H, -△SF) B) and D)
G) None of the above

Exam 8: An Introduction to Metabolism

Which of the following is most similar in structure to ATP?

Correct Answer
verified

Which of the following statements is True concerning catabolic pathways?

Correct Answer
verified

Most cells cannot harness heat to perform work because

Correct Answer
verified

Use Figure 8.3 to answer the following questions. -In coupled reactions, in which direction would the endergonic reaction be driven relative to the clockwise direction of the ATP reaction above and shown in the figure?

Correct Answer
verified

The following questions are based on the reaction A + B → C + D shown in Figure 8.2. -Which of the following represents the △G of the reaction?

Correct Answer
verified

Which of the following types of reactions would decrease the entropy within a cell?

Correct Answer
verified

Correct Answer
verified

When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows:

Correct Answer
verified

When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any) in the cell?

Correct Answer
verified

Why is ATP an important molecule in metabolism?

Correct Answer
verified

When 10,000 molecules of ATP are hydrolyzed to ADP and Pi in a test tube, about twice as much heat is liberated as when a cell hydrolyzes the same amount of ATP. Which of the following is the best explanation for this observation?

Correct Answer
verified

Some bacteria are metabolically active in hot springs because

Correct Answer
verified

The following questions are based on the reaction A + B → C + D shown in Figure 8.2. -Which of the following bests describes the reaction?

Correct Answer
verified

Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity?

Correct Answer
verified

Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?

Correct Answer
verified

If an enzyme solution is saturated with substrate, the most effective way to obtain a faster yield of products is to

Correct Answer
verified

The following questions are based on the reaction A + B → C + D shown in Figure 8.2. -How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?

Correct Answer
verified

Refer to Figure 8.1 to answer the following questions. -Which curve was most likely generated from an enzyme that requires a cofactor?

Correct Answer
verified

The following questions are based on the reaction A + B → C + D shown in Figure 8.2. -Which of the following represents the activation energy required for a noncatalyzed reaction?

Correct Answer
verified

Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as a(n)

Correct Answer
verified

Exam 8: An Introduction to Metabolism

Which of the following is most similar in structure to ATP?

Correct AnswerverifiedShow Answer

Which of the following statements is True concerning catabolic pathways?

Correct AnswerverifiedShow Answer

Most cells cannot harness heat to perform work because

Correct AnswerverifiedShow Answer

Use Figure 8.3 to answer the following questions. -In coupled reactions, in which direction would the endergonic reaction be driven relative to the clockwise direction of the ATP reaction above and shown in the figure?

Correct AnswerverifiedShow Answer

The following questions are based on the reaction A + B → C + D shown in Figure 8.2. -Which of the following represents the △G of the reaction?

Correct AnswerverifiedShow Answer

Which of the following types of reactions would decrease the entropy within a cell?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows:

Correct AnswerverifiedShow Answer

When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any) in the cell?

Correct AnswerverifiedShow Answer

Why is ATP an important molecule in metabolism?

Correct AnswerverifiedShow Answer

When 10,000 molecules of ATP are hydrolyzed to ADP and Pi in a test tube, about twice as much heat is liberated as when a cell hydrolyzes the same amount of ATP. Which of the following is the best explanation for this observation?

Correct AnswerverifiedShow Answer

Some bacteria are metabolically active in hot springs because

Correct AnswerverifiedShow Answer

The following questions are based on the reaction A + B → C + D shown in Figure 8.2. -Which of the following bests describes the reaction?

Correct AnswerverifiedShow Answer

Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity?

Correct AnswerverifiedShow Answer

Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?

Correct AnswerverifiedShow Answer

If an enzyme solution is saturated with substrate, the most effective way to obtain a faster yield of products is to

Correct AnswerverifiedShow Answer

The following questions are based on the reaction A + B → C + D shown in Figure 8.2. -How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?

Correct AnswerverifiedShow Answer

Refer to Figure 8.1 to answer the following questions. -Which curve was most likely generated from an enzyme that requires a cofactor?

Correct AnswerverifiedShow Answer

The following questions are based on the reaction A + B → C + D shown in Figure 8.2. -Which of the following represents the activation energy required for a noncatalyzed reaction?

Correct AnswerverifiedShow Answer

Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as a(n)

Correct AnswerverifiedShow Answer

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