Question 1

Which of the following statements describes enzyme cooperativity?

Accepted Answer

A)  A multienzyme complex contains all the enzymes of a metabolic pathway. 
B)  A product of a pathway serves as a competitive inhibitor of an early enzyme in the pathway. 
C)  A substrate molecule bound to an active site of one subunit promotes substrate binding to the active site of other subunits. 
D)  Several substrate molecules can be catalyzed by the same enzyme. 
E)  A substrate binds to an active site and inhibits cooperation between enzymes in a pathway. 
A)  A multienzyme complex contains all the enzymes of a metabolic pathway. 
B)  A product of a pathway serves as a competitive inhibitor of an early enzyme in the pathway. 
C)  A substrate molecule bound to an active site of one subunit promotes substrate binding to the active site of other subunits. 
D)  Several substrate molecules can be catalyzed by the same enzyme. 
E)  A substrate binds to an active site and inhibits cooperation between enzymes in a pathway.

Question 2

Which of the following best describes enthalpy (H)?

Accepted Answer

A)  the total kinetic energy of a system 
B)  the heat content of a chemical system 
C)  the system's entropy 
D)  the cell's energy equilibrium 
E)  the condition of a cell that is not able to react 
A)  the total kinetic energy of a system 
B)  the heat content of a chemical system 
C)  the system's entropy 
D)  the cell's energy equilibrium 
E)  the condition of a cell that is not able to react

Question 3

A series of enzymes catalyze the reaction X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme.
-What is substance X?

Accepted Answer

A)  a coenzyme 
B)  an allosteric inhibitor 
C)  a substrate 
D)  an intermediate 
E)  the product 
A)  a coenzyme 
B)  an allosteric inhibitor 
C)  a substrate 
D)  an intermediate 
E)  the product

Question 4

The following questions are based on the reaction A + B ↔ C + D shown in Figure 8.1.
   
Figure 8.1
-Which of the following in Figure 8.1 would be the same in either an enzyme-catalyzed or a noncatalyzed reaction?

Accepted Answer

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

Question 5

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

Accepted Answer

A)  The phosphate is released as an excretory waste. 
B)  The phosphate can only be used to regenerate more ATP. 
C)  The phosphate can be added to water and excreted as a liquid. 
D)  The phosphate may be incorporated into any molecule that contains phosphate. 
E)  It enters the nucleus to affect gene expression. 
A)  The phosphate is released as an excretory waste. 
B)  The phosphate can only be used to regenerate more ATP. 
C)  The phosphate can be added to water and excreted as a liquid. 
D)  The phosphate may be incorporated into any molecule that contains phosphate. 
E)  It enters the nucleus to affect gene expression.

Question 6

The following questions are based on the reaction A + B ↔ C + D shown in Figure 8.1.
   
Figure 8.1
-Which of the following represents the activation energy required for the enzyme-catalyzed reaction in Figure 8.1?

Accepted Answer

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

Question 7

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

Accepted Answer

A)  a pentose sugar 
B)  a DNA nucleotide 
C)  an RNA nucleotide 
D)  an amino acid with three phosphate groups attached 
E)  a phospholipid 
A)  a pentose sugar 
B)  a DNA nucleotide 
C)  an RNA nucleotide 
D)  an amino acid with three phosphate groups attached 
E)  a phospholipid

Question 8

The following questions are based on the reaction A + B ↔ C + D shown in Figure 8.1.
   
Figure 8.1
-Assume that the reaction in Figure 8.1 has a ΔG of -5.6 kcal/mol. Which of the following would be true?

Accepted Answer

A)  The reaction could be coupled to power an endergonic reaction with a ΔG of +6.2 kcal/mol. 
B)  The reaction could be coupled to power an exergonic reaction with a ΔG of +8.8 kcal/mol. 
C)  The reaction would result in a decrease in entropy (S) and an increase in the total energy content (H) of the system. 
D)  The reaction would result in an increase in entropy (S) and a decrease in the total energy content (H) of the system. 
E)  The reaction would result in products (C + 
D)  with a greater free-energy content than in the initial reactants (A + 
B) . 
A)  The reaction could be coupled to power an endergonic reaction with a ΔG of +6.2 kcal/mol. 
B)  The reaction could be coupled to power an exergonic reaction with a ΔG of +8.8 kcal/mol. 
C)  The reaction would result in a decrease in entropy (S) and an increase in the total energy content (H) of the system. 
D)  The reaction would result in an increase in entropy (S) and a decrease in the total energy content (H) of the system. 
E)  The reaction would result in products (C + 
D)  with a greater free-energy content than in the initial reactants (A + 
B) .

Question 9

Which of the following statements is a logical consequence of the second law of thermodynamics?

Accepted Answer

A)  If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. 
B)  If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. 
C)  Every energy transfer requires activation energy from the environment. 
D)  Every chemical reaction must increase the total entropy of the universe. 
E)  Energy can be transferred or transformed, but it cannot be created or destroyed. 
A)  If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. 
B)  If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. 
C)  Every energy transfer requires activation energy from the environment. 
D)  Every chemical reaction must increase the total entropy of the universe. 
E)  Energy can be transferred or transformed, but it cannot be created or destroyed.

Question 10

The following questions are based on the reaction A + B ↔ C + D shown in Figure 8.1.
   
Figure 8.1
-Which of the following represents the activation energy needed for the noncatalyzed reverse reaction, C + D → A + B, in Figure 8.1?

Accepted Answer

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

Question 11

Which of the following is a statement of the first law of thermodynamics?

Accepted Answer

A)  Energy cannot be created or destroyed. 
B)  The entropy of the universe is decreasing. 
C)  The entropy of the universe is constant. 
D)  Kinetic energy is stored energy that results from the specific arrangement of matter. 
E)  Energy cannot be transferred or transformed. 
A)  Energy cannot be created or destroyed. 
B)  The entropy of the universe is decreasing. 
C)  The entropy of the universe is constant. 
D)  Kinetic energy is stored energy that results from the specific arrangement of matter. 
E)  Energy cannot be transferred or transformed.

Question 12

According to the induced fit hypothesis of enzyme catalysis, which of the following is correct?

Accepted Answer

A)  The binding of the substrate depends on the shape of the active site. 
B)  Some enzymes change their structure when activators bind to the enzyme. 
C)  A competitive inhibitor can outcompete the substrate for the active site. 
D)  The binding of the substrate changes the shape of the enzyme's active site. 
E)  The active site creates a microenvironment ideal for the reaction. 
A)  The binding of the substrate depends on the shape of the active site. 
B)  Some enzymes change their structure when activators bind to the enzyme. 
C)  A competitive inhibitor can outcompete the substrate for the active site. 
D)  The binding of the substrate changes the shape of the enzyme's active site. 
E)  The active site creates a microenvironment ideal for the reaction.

Question 13

Whenever energy is transformed, there is always an increase in the

Accepted Answer

A)  free energy of the system. 
B)  free energy of the universe. 
C)  entropy of the system. 
D)  entropy of the universe. 
E)  enthalpy of the universe. 
A)  free energy of the system. 
B)  free energy of the universe. 
C)  entropy of the system. 
D)  entropy of the universe. 
E)  enthalpy of the universe.

Question 14

Which of the following shows the correct changes in thermodynamic properties for a chemical reaction in which amino acids are linked to form a protein?

Accepted Answer

A)  +ΔH, +ΔS, +ΔG 
B)  +ΔH, -ΔS, -ΔG 
C)  +ΔH, -ΔS, +ΔG 
D)  -ΔH, -ΔS, +ΔG 
E)  -ΔH, +ΔS, +ΔG 
A)  +ΔH, +ΔS, +ΔG 
B)  +ΔH, -ΔS, -ΔG 
C)  +ΔH, -ΔS, +ΔG 
D)  -ΔH, -ΔS, +ΔG 
E)  -ΔH, +ΔS, +ΔG

Question 15

Which of the following is the smallest closed system?

Accepted Answer

A)  a cell 
B)  an organism 
C)  an ecosystem 
D)  Earth 
E)  the universe 
A)  a cell 
B)  an organism 
C)  an ecosystem 
D)  Earth 
E)  the universe

Question 16

Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's

Accepted Answer

A)  entropy. 
B)  activation energy. 
C)  endothermic level. 
D)  equilibrium point. 
E)  free-energy content. 
A)  entropy. 
B)  activation energy. 
C)  endothermic level. 
D)  equilibrium point. 
E)  free-energy content.

Question 17

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 entropy must increase with time. 
B)  Life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is exactly balanced by an increase in the entropy of the universe. 
C)  Living organisms do not follow the laws of thermodynamics. 
D)  As a consequence of growing, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their growth. 
E)  Living organisms are able to transform energy into entropy. 
A)  Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time. 
B)  Life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is exactly balanced by an increase in the entropy of the universe. 
C)  Living organisms do not follow the laws of thermodynamics. 
D)  As a consequence of growing, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their growth. 
E)  Living organisms are able to transform energy into entropy.

Question 18

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

Accepted Answer

A)  cessation of cellular protein synthesis 
B)  localization of enzymes into specific organelles or membranes 
C)  exporting enzymes out of the cell 
D)  connecting enzymes into large aggregates 
E)  hydrophobic interactions 
A)  cessation of cellular protein synthesis 
B)  localization of enzymes into specific organelles or membranes 
C)  exporting enzymes out of the cell 
D)  connecting enzymes into large aggregates 
E)  hydrophobic interactions

Question 19

-How do cells use the ATP cycle shown 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 to generate or consume water molecules as needed. 
E)  Cells use the cycle primarily to generate heat. 
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 to generate or consume water molecules as needed. 
E)  Cells use the cycle primarily to generate heat.

Question 20

When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?

Accepted Answer

A)  It is used to power yet more cellular work. 
B)  It is used to store energy as more ATP. 
C)  It is used to generate ADP from nucleotide precursors. 
D)  It is lost to the environment. 
E)  It is transported to specific organs such as the brain. 
A)  It is used to power yet more cellular work. 
B)  It is used to store energy as more ATP. 
C)  It is used to generate ADP from nucleotide precursors. 
D)  It is lost to the environment. 
E)  It is transported to specific organs such as the brain.

Exam 8: An Introduction to Metabolism

Which of the following statements describes enzyme cooperativity?

Which of the following best describes enthalpy (H)?

A series of enzymes catalyze the reaction X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. -What is substance X?

The following questions are based on the reaction A + B ↔ C + D shown in Figure 8.1. Figure 8.1 -Which of the following in Figure 8.1 would be the same in either an enzyme-catalyzed or a noncatalyzed reaction?

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

The following questions are based on the reaction A + B ↔ C + D shown in Figure 8.1. Figure 8.1 -Which of the following represents the activation energy required for the enzyme-catalyzed reaction in Figure 8.1?

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

The following questions are based on the reaction A + B ↔ C + D shown in Figure 8.1. Figure 8.1 -Assume that the reaction in Figure 8.1 has a ΔG of -5.6 kcal/mol. Which of the following would be true?

Which of the following statements is a logical consequence of the second law of thermodynamics?

The following questions are based on the reaction A + B ↔ C + D shown in Figure 8.1. Figure 8.1 -Which of the following represents the activation energy needed for the noncatalyzed reverse reaction, C + D → A + B, in Figure 8.1?

Which of the following is a statement of the first law of thermodynamics?

According to the induced fit hypothesis of enzyme catalysis, which of the following is correct?

Whenever energy is transformed, there is always an increase in the

Which of the following shows the correct changes in thermodynamic properties for a chemical reaction in which amino acids are linked to form a protein?

Which of the following is the smallest closed system?

Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's

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?

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

-How do cells use the ATP cycle shown in the figure?

When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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