Question 1

Which of the following statements is true concerning catabolic pathways?

Accepted Answer

A) They combine molecules into more energy-rich molecules. 
B) They supply energy, primarily in the form of ATP, for the cell's work. 
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. 
A) They combine molecules into more energy-rich molecules. 
B) They supply energy, primarily in the form of ATP, for the cell's work. 
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.

Question 2

The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is most precisely described as

Accepted Answer

A) metabolic inhibition. 
B) feedback inhibition. 
C) allosteric inhibition. 
D) noncooperative inhibition. 
E) reversible inhibition. 
A) metabolic inhibition. 
B) feedback inhibition. 
C) allosteric inhibition. 
D) noncooperative inhibition. 
E) reversible inhibition.

Question 3

Which of the following is an example of cooperativity?

Accepted Answer

A) the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway 
B) one enzyme in a metabolic pathway passing its product to act as a substrate for the next enzyme in the pathway 
C) a molecule binding at one unit of a tetramer, allowing faster binding at each of the other three 
D) the effect of increasing temperature on the rate of an enzymatic reaction 
E) binding of an ATP molecule along with one of the substrate molecules in an active site 
A) the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway 
B) one enzyme in a metabolic pathway passing its product to act as a substrate for the next enzyme in the pathway 
C) a molecule binding at one unit of a tetramer, allowing faster binding at each of the other three 
D) the effect of increasing temperature on the rate of an enzymatic reaction 
E) binding of an ATP molecule along with one of the substrate molecules in an active site

Question 4

What is the difference (if any)between the structure of ATP and the structure of the precursor of the A nucleotide in RNA?

Accepted Answer

A) The sugar molecule is different. 
B) The nitrogen-containing base is different. 
C) The number of phosphates is three instead of one. 
D) The number of phosphates is three instead of two. 
E) There is no difference. 
A) The sugar molecule is different. 
B) The nitrogen-containing base is different. 
C) The number of phosphates is three instead of one. 
D) The number of phosphates is three instead of two. 
E) There is no difference.

Question 5

The mathematical expression for the change in free energy of a system is ΔG = ΔH - TΔS.Which of the following is (are)correct?

Accepted Answer

A) ΔS is the change in enthalpy, a measure of randomness. 
B) ΔH is the change in entropy, the energy available to do work. 
C) ΔG is the change in free energy. 
D) T is the temperature in degrees Celsius. 
E) T is the temperature in degrees Fahrenheit. 
A) ΔS is the change in enthalpy, a measure of randomness. 
B) ΔH is the change in entropy, the energy available to do work. 
C) ΔG is the change in free energy. 
D) T is the temperature in degrees Celsius. 
E) T is the temperature in degrees Fahrenheit.

Question 6

The following questions are based on the reaction A + B ↔ C + D shown in the figure below.
  
-Which of the following represents the ΔG of the reaction in the figure above?

Accepted Answer

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

Question 7

The active site of an enzyme is the region that

Accepted Answer

A) binds allosteric regulators of the enzyme. 
B) is involved in the catalytic reaction of the enzyme. 
C) binds noncompetitive inhibitors of the enzyme. 
D) is inhibited by the presence of a coenzyme or a cofactor. 
A) binds allosteric regulators of the enzyme. 
B) is involved in the catalytic reaction of the enzyme. 
C) binds noncompetitive inhibitors of the enzyme. 
D) is inhibited by the presence of a coenzyme or a cofactor.

Question 8

The following questions are based on the reaction A + B ↔ C + D shown in the figure below.
  
-Which of the following in the figure above 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 9

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 10

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

Accepted Answer

A) anabolic reactions 
B) hydrolysis 
C) respiration 
D) digestion 
E) catabolic reactions 
A) anabolic reactions 
B) hydrolysis 
C) respiration 
D) digestion 
E) catabolic reactions

Question 11

A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because

Accepted Answer

A) the starch solution has less free energy than the sugar solution. 
B) the hydrolysis of starch to sugar is endergonic. 
C) the activation energy barrier for this reaction cannot be surmounted. 
D) starch cannot be hydrolyzed in the presence of so much water. 
E) starch hydrolysis is nonspontaneous. 
A) the starch solution has less free energy than the sugar solution. 
B) the hydrolysis of starch to sugar is endergonic. 
C) the activation energy barrier for this reaction cannot be surmounted. 
D) starch cannot be hydrolyzed in the presence of so much water. 
E) starch hydrolysis is nonspontaneous.

Question 12

The following questions are based on the reaction A + B ↔ C + D shown in the figure below.
  
-Which of the following represents the activation energy needed for the enzyme-catalyzed reverse reaction,C + D → A + B,in the figure above?

Accepted Answer

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

Question 13

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

Question 14

A molecule binds between two subunits and stabilizes the active form of an enzyme.What does this describe?

Accepted Answer

A) allosteric inhibition 
B) allosteric activation 
C) cooperativity 
D) competitive activation 
E) feedback activation 
A) allosteric inhibition 
B) allosteric activation 
C) cooperativity 
D) competitive activation 
E) feedback activation

Question 15

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) It is one of the four building blocks for DNA synthesis. 
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) It is one of the four building blocks for DNA synthesis.

Question 16

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 17

A reaction that absorbs free energy from its surroundings is a(n)________ reaction.

Accepted Answer

A) spontaneous 
B) endothermic 
C) exothermic 
D) endergonic 
E) exergonic 
A) spontaneous 
B) endothermic 
C) exothermic 
D) endergonic 
E) exergonic

Question 18

Protein kinases are enzymes that transfer the terminal phosphate from ATP to an amino acid residue on the target protein.Many are located in/on the plasma membrane as integral membrane proteins or peripheral membrane proteins.What purpose may be served by their plasma membrane localization?

Accepted Answer

A) Membrane localization allows for unique protein folding of the protein kinases. 
B) Protein kinases can more readily encounter and phosphorylate other membrane proteins. 
C) Membrane localization lowers the activation energy of the phosphorylation reaction. 
D) Protein kinases flip back and forth across the membrane to access target proteins on either side. 
E) Protein kinases require phospholipids as a cofactor. 
A) Membrane localization allows for unique protein folding of the protein kinases. 
B) Protein kinases can more readily encounter and phosphorylate other membrane proteins. 
C) Membrane localization lowers the activation energy of the phosphorylation reaction. 
D) Protein kinases flip back and forth across the membrane to access target proteins on either side. 
E) Protein kinases require phospholipids as a cofactor.

Question 19

Although unlikely,if your fever exceeded 41◦C what might be a consequence?

Accepted Answer

A) destruction of your enzymes' primary structure 
B) removal of amine groups from your proteins 
C) change in the tertiary structure of your enzymes 
D) removal of the amino acids in active sites of your enzymes 
E) binding of your enzymes to inappropriate substrates 
A) destruction of your enzymes' primary structure 
B) removal of amine groups from your proteins 
C) change in the tertiary structure of your enzymes 
D) removal of the amino acids in active sites of your enzymes 
E) binding of your enzymes to inappropriate substrates

Question 20

Which of the following metabolic processes can occur without a net influx of energy from some other process?

Accepted Answer

A) ADP + ℗ᵢ → ATP + H₂O 
B) C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O 
C) 6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂ 
D) amino acids → protein 
E) glucose + fructose → sucrose 
A) ADP + ℗ᵢ → ATP + H₂O 
B) C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O 
C) 6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂ 
D) amino acids → protein 
E) glucose + fructose → sucrose

Exam 8: An Introduction to Metabolism

Which of the following statements is true concerning catabolic pathways?

The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is most precisely described as

Which of the following is an example of cooperativity?

What is the difference (if any)between the structure of ATP and the structure of the precursor of the A nucleotide in RNA?

The mathematical expression for the change in free energy of a system is ΔG = ΔH - TΔS.Which of the following is (are)correct?

The following questions are based on the reaction A + B ↔ C + D shown in the figure below. -Which of the following represents the ΔG of the reaction in the figure above?

The active site of an enzyme is the region that

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

Which of the following best describes enthalpy (H)?

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

A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because

The following questions are based on the reaction A + B ↔ C + D shown in the figure below. -Which of the following represents the activation energy needed for the enzyme-catalyzed reverse reaction,C + D → A + B,in the figure above?

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

A molecule binds between two subunits and stabilizes the active form of an enzyme.What does this describe?

Why is ATP an important molecule in metabolism?

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?

A reaction that absorbs free energy from its surroundings is a(n)________ reaction.

Protein kinases are enzymes that transfer the terminal phosphate from ATP to an amino acid residue on the target protein.Many are located in/on the plasma membrane as integral membrane proteins or peripheral membrane proteins.What purpose may be served by their plasma membrane localization?

Although unlikely,if your fever exceeded 41◦C what might be a consequence?

Which of the following metabolic processes can occur without a net influx of energy from some other process?

Introduction: Evolution and Themes of Biology

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

DNA Tools and 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 Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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