Question 1

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. 
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 2

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

Question 3

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

Question 4

The mathematical expression for the change in free energy of a system is ΔG = ΔH - TΔS. Which of the following statements is 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. 
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.

Question 5

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. 
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 6

Why is the ΔG of ATP hydrolysis in the cell about twice as great as the ΔG of ATP hydrolysis in a test tube under standard conditions?

Accepted Answer

A)  A cell is an open system, whereas a test tube is a closed system. 
B)  ATP hydrolysis in a test tube releases more heat than ATP hydrolysis associated with cellular metabolism. 
C)  Reactant and product concentrations in the test tube are different from those in the cell. 
D)  ATP hydrolysis in cells is catalyzed by enzymes, whereas the reaction in a test tube occurs spontaneously. 
A)  A cell is an open system, whereas a test tube is a closed system. 
B)  ATP hydrolysis in a test tube releases more heat than ATP hydrolysis associated with cellular metabolism. 
C)  Reactant and product concentrations in the test tube are different from those in the cell. 
D)  ATP hydrolysis in cells is catalyzed by enzymes, whereas the reaction in a test tube occurs spontaneously.

Question 7

Characterization of the complete three-dimensional structure of a newly purified protein suggests that it catalyzes the breakdown of a large substrate. The protein consists of a single polypeptide chain. It has a large pocket that appears to be the binding site for the substrate and a smaller indentation that appears to be the binding site for a regulatory molecule. What do these structural observations suggest about the mechanism by which the activity of this protein is likely regulated?

Accepted Answer

A)  It is probably an enzyme that is regulated by noncompetitive inhibition. 
B)  It is probably a multi-subunit enzyme that is regulated by allosteric regulation. 
C)  It is probably an enzyme that is regulated by competitive inhibition. 
D)  It is probably an enzyme that is regulated by cooperativity. 
A)  It is probably an enzyme that is regulated by noncompetitive inhibition. 
B)  It is probably a multi-subunit enzyme that is regulated by allosteric regulation. 
C)  It is probably an enzyme that is regulated by competitive inhibition. 
D)  It is probably an enzyme that is regulated by cooperativity.

Exam 8: An Introduction to Metabolism

Some bacteria are metabolically active in hot springs because

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

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

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

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

Why is the ΔG of ATP hydrolysis in the cell about twice as great as the ΔG of ATP hydrolysis in a test tube under standard conditions?

Evolution, the Themes of Biology, and Scientific Inquiry

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

Gene Expression: 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

Vascular 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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