Question 1

Which of the following statements about the evolution of life on Earth, from simple prokaryote-like cells to multicellular eukaryotic organisms, is true?

Accepted Answer

A)   By resulting in such diversity and complexity of life, it is an exception to the second law of thermodynamics.
B)   It has occurred in accordance with the laws of thermodynamics and resulted in a substantial increase in the entropy of the planet.
C)   It has occurred in accordance with the laws of thermodynamics and resulted in a substantial increase in the total energy in the universe.
D)   It has occurred in accordance with the laws of thermodynamics and resulted in a substantial decrease in the entropy of the planet.

Question 2

Which of the following terms most precisely describes the cellular process of breaking down large molecules into smaller ones?

Accepted Answer

A)   catabolism (catabolic pathways) 
B)   metabolism
C)   anabolism (anabolic pathways) 
D)   dehydration

Question 3

Which of the following is a primary function of the active site of an enzyme?

Accepted Answer

A)   It binds allosteric regulators of the enzyme.
B)   It binds noncompetitive inhibitors of the enzyme.
C)   It catalyzes the reaction associated with the enzyme.
D)   It is activated by the presence of the end product of the metabolic pathway in which the enzyme is involved.

Question 4

Use the following information to answer the question below.

Rate of an enzyme-catalyzed reaction as a function of varying reactant concentration, with the concentration of enzyme constant
In the figure, why does the reaction rate plateau at higher reactant concentrations?

Accepted Answer

A)   Feedback inhibition by product occurs at high reactant concentrations.
B)   Most enzyme molecules are occupied by substrate at high reactant concentrations.
C)   The reaction nears equilibrium at high reactant concentrations.
D)   The rate of the reverse reaction increases at high reactant concentrations.

Question 5

Some bacteria are metabolically active in hot springs because

Accepted Answer

A)   they are able to maintain a lower internal temperature.
B)   high temperatures make catalysis unnecessary.
C)   their enzymes have high optimal temperatures.
D)   their enzymes are completely insensitive to temperature.

Question 6

Which of the following statements is an important consequence of the first law of thermodynamics for a living organism?

Accepted Answer

A)   The energy content of an organism is constant.
B)   An organism ultimately must obtain all of the necessary energy for life from its environment.
C)   The entropy of an organism decreases with time as the organism grows in complexity.
D)   Organisms grow by converting energy into organic matter.

Question 7

Most cells cannot harness heat to perform work because ________.

Accepted Answer

A)   heat is not a form of energy
B)   temperature is usually uniform throughout a cell
C)   heat can never be used to do work
D)   heat must remain constant during work

Question 8

What is the name of the thermodynamic barrier that must be overcome before products are formed in a spontaneous reaction?

Accepted Answer

A)   entropy
B)   activation energy
C)   the equilibrium point
D)   free energy

Question 9

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

Accepted Answer

A)   a noncompetitive inhibitor of the enzyme
B)   an allosteric activator of the enzyme
C)   a cofactor necessary for enzyme activity
D)   a coenzyme derived from a vitamin

Question 10

Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?

Accepted Answer

A)   Living organisms do not obey the second law of thermodynamics, which states that the entropy of an organism increases with each energy transformation.
B)   The decrease in entropy is associated with growth of an organism. As a consequence of growth, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their increased complexity.
C)   As a consequence of growth, the decrease in entropy of the organism is associated with a corresponding decrease in the entropy of the universe.
D)   Living organisms are able to transform chemical energy into entropy.

Question 11

Which of the following statements describes a central role that ATP plays in cellular metabolism?

Accepted Answer

A)   Hydrolysis of ATP provides an input of free energy for exergonic reactions.
B)   ATP provides energy coupling between exergonic and endergonic reactions.
C)   Hydrolysis of the terminal phosphate group stores free energy that is used for cellular work.
D)   Its terminal phosphate bond is stronger than most covalent bonds in other biological macromolecules.

Question 12

Which of the following conditions may be overcome by increasing the substrate concentration in an enzymatic reaction with a fixed amount of enzyme?

Accepted Answer

A)   the need for a coenzyme
B)   allosteric inhibition
C)   noncompetitive inhibition
D)   competitive inhibition

Question 13

How do cells use the ATP cycle illustrated in the figure?

Accepted Answer

A)   Cells use the cycle to recycle ADP and phosphate.
B)   Cells use the cycle to recycle energy released by ATP hydrolysis.
C)   Cells use the cycle to recycle ADP, phosphate, and the energy released by ATP hydrolysis.
D)   Cells use the cycle primarily to generate heat.

Question 14

Most cells cannot harness heat to perform work because

Accepted Answer

A)   heat does not involve a transfer of energy.
B)   cells do not have much thermal energy; they are relatively cool.
C)   temperature is usually uniform throughout a cell.
D)   heat can never be used to do work.

Question 15

Use the following information to answer the question below.

Activity of various enzymes at various temperatures (a)  and at various pH (b) 
Which curves on the graphs may represent the temperature and pH profiles of an enzyme taken from a bacterium that lives in a mildly alkaline hot springs at temperatures of 70°C or higher?

Accepted Answer

A)   curves 1 and 5
B)   curves 2 and 5
C)   curves 3 and 4
D)   curves 3 and 5

Question 16

Use the following information to answer the question below.

The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following in the figure would be the same in either an enzyme-catalyzed or a noncatalyzed reaction?

Accepted Answer

A)   a
B)   b
C)   c
D)   d

Question 17

Which of the following characteristics is most likely to be associated with an enzyme that catalyzes two different chemical reactions?

Accepted Answer

A)   The enzyme contains α-helices and β-pleated sheets.
B)   The enzyme is subject to competitive inhibition and allosteric regulation.
C)   The enzyme is composed of at least two subunits.
D)   Either the enzyme has two distinct active sites or the substrates involved in the two reactions have very similar structures.

Question 18

The relationship between catabolism and anabolism is most similar to the relationship between which of the following pairs of terms?

Accepted Answer

A)   exergonic; spontaneous
B)   exergonic; endergonic
C)   free energy; entropy
D)   work; free energy

Question 19

Use the following information to answer the question below.

The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following represents the activation energy required for the enzyme-catalyzed reaction in the figure?

Accepted Answer

A)   a
B)   b
C)   c
D)   d

Question 20

Which of the following statements is true of metabolism in its entirety in all organisms?

Accepted Answer

A)   Metabolism depends on a constant supply of energy from food.
B)   Metabolism uses all of an organism's resources.
C)   Metabolism consists of all the energy transformation reactions in an organism.
D)   Metabolism manages the increase of entropy in an organism.

Exam 8: An Introduction to Metabolism

Most cells cannot harness heat to perform work because

Correct Answer
verified

Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?

Correct Answer
verified

Which of the following terms most precisely describes the cellular process of breaking down large molecules into smaller ones?

Correct Answer
verified

Which of the following statements describes a central role that ATP plays in cellular metabolism?

Correct Answer
verified

Which of the following statements about the evolution of life on Earth, from simple prokaryote-like cells to multicellular eukaryotic organisms, is true?

Correct Answer
verified

Most cells cannot harness heat to perform work because ________.

Correct Answer
verified

Some bacteria are metabolically active in hot springs because

Correct Answer
verified

How do cells use the ATP cycle illustrated in the figure?

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 ________.

Correct Answer
verified

The relationship between catabolism and anabolism is most similar to the relationship between which of the following pairs of terms?

Correct Answer
verified

Use the following information to answer the question below. Rate of an enzyme-catalyzed reaction as a function of varying reactant concentration, with the concentration of enzyme constant In the figure, why does the reaction rate plateau at higher reactant concentrations?

Correct Answer
verified

Use the following information to answer the question below. The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following in the figure would be the same in either an enzyme-catalyzed or a noncatalyzed reaction?

Correct Answer
verified

Which of the following statements is true of metabolism in its entirety in all organisms?

Correct Answer
verified

Which of the following statements is an important consequence of the first law of thermodynamics for a living organism?

Correct Answer
verified

Which of the following characteristics is most likely to be associated with an enzyme that catalyzes two different chemical reactions?

Correct Answer
verified

Which of the following conditions may be overcome by increasing the substrate concentration in an enzymatic reaction with a fixed amount of enzyme?

Correct Answer
verified

Correct Answer
verified

Which of the following is a primary function of the active site of an enzyme?

Correct Answer
verified

Use the following information to answer the question below. The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following represents the activation energy required for the enzyme-catalyzed reaction in the figure?

Correct Answer
verified

What is the name of the thermodynamic barrier that must be overcome before products are formed in a spontaneous reaction?

Correct Answer
verified

Exam 8: An Introduction to Metabolism

Most cells cannot harness heat to perform work because

Correct AnswerverifiedShow Answer

Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?

Correct AnswerverifiedShow Answer

Which of the following terms most precisely describes the cellular process of breaking down large molecules into smaller ones?

Correct AnswerverifiedShow Answer

Which of the following statements describes a central role that ATP plays in cellular metabolism?

Correct AnswerverifiedShow Answer

Which of the following statements about the evolution of life on Earth, from simple prokaryote-like cells to multicellular eukaryotic organisms, is true?

Correct AnswerverifiedShow Answer

Most cells cannot harness heat to perform work because ________.

Correct AnswerverifiedShow Answer

Some bacteria are metabolically active in hot springs because

Correct AnswerverifiedShow Answer

How do cells use the ATP cycle illustrated in the figure?

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 ________.

Correct AnswerverifiedShow Answer

The relationship between catabolism and anabolism is most similar to the relationship between which of the following pairs of terms?

Correct AnswerverifiedShow Answer

Use the following information to answer the question below. Rate of an enzyme-catalyzed reaction as a function of varying reactant concentration, with the concentration of enzyme constant In the figure, why does the reaction rate plateau at higher reactant concentrations?

Correct AnswerverifiedShow Answer

Use the following information to answer the question below. The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following in the figure would be the same in either an enzyme-catalyzed or a noncatalyzed reaction?

Correct AnswerverifiedShow Answer

Which of the following statements is true of metabolism in its entirety in all organisms?

Correct AnswerverifiedShow Answer

Which of the following statements is an important consequence of the first law of thermodynamics for a living organism?

Correct AnswerverifiedShow Answer

Which of the following characteristics is most likely to be associated with an enzyme that catalyzes two different chemical reactions?

Correct AnswerverifiedShow Answer

Which of the following conditions may be overcome by increasing the substrate concentration in an enzymatic reaction with a fixed amount of enzyme?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following is a primary function of the active site of an enzyme?

Correct AnswerverifiedShow Answer

Use the following information to answer the question below. The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following represents the activation energy required for the enzyme-catalyzed reaction in the figure?

Correct AnswerverifiedShow Answer

What is the name of the thermodynamic barrier that must be overcome before products are formed in a spontaneous reaction?

Correct AnswerverifiedShow Answer

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