Question 1

Which of the following statements about ATP is false?

Accepted Answer

A)  The synthesis of ATP is an endergonic reaction. 
B)  The hydrolysis of ATP to ADP and Pi is an exergonic reaction. 
C)  The phosphate bond energy of ATP is used to power catabolic metabolism. 
D)  ATP is a building block of RNA. 
E)  The phosphate bond energy of ATP may be transformed into light. 
A)  The synthesis of ATP is an endergonic reaction. 
B)  The hydrolysis of ATP to ADP and Pi is an exergonic reaction. 
C)  The phosphate bond energy of ATP is used to power catabolic metabolism. 
D)  ATP is a building block of RNA. 
E)  The phosphate bond energy of ATP may be transformed into light.

Question 2

End products of biosynthetic pathways often act to block the initial step in that pathway. This phenomenon is called

Accepted Answer

A)  allosteric inhibition. 
B)  denaturation. 
C)  branch pathway inhibition. 
D)  feedback inhibition. 
E)  binary inhibition. 
A)  allosteric inhibition. 
B)  denaturation. 
C)  branch pathway inhibition. 
D)  feedback inhibition. 
E)  binary inhibition.

Question 3

Allosteric inhibitors act by

Accepted Answer

A)  decreasing the number of enzyme molecules. 
B)  increasing the number of enzyme molecules. 
C)  decreasing the amount of the inactive form of the enzyme. 
D)  decreasing the amount of the active form of the enzyme. 
E)  increasing the amount of substrate. 
A)  decreasing the number of enzyme molecules. 
B)  increasing the number of enzyme molecules. 
C)  decreasing the amount of the inactive form of the enzyme. 
D)  decreasing the amount of the active form of the enzyme. 
E)  increasing the amount of substrate.

Question 4

Explain how free energy, total energy, temperature, and entropy are related.

Accepted Answer

Total energy = free

Question 5

The enzyme glucose oxidase binds the six-carbon sugar glucose and catalyzes its conversion to glucono-1,4-actone. Mannose is also a six-carbon sugar, but glucose oxidase cannot bind mannose. The specificity of glucose oxidase is based on the

Accepted Answer

A)  free energy of the transition state. 
B)  activation energy of the reaction. 
C)  change in free energy of the reaction. 
D)  three-dimensional shape and structure of the active site. 
E)  rate constant of the reaction. 
A)  free energy of the transition state. 
B)  activation energy of the reaction. 
C)  change in free energy of the reaction. 
D)  three-dimensional shape and structure of the active site. 
E)  rate constant of the reaction.

Question 6

When a drop of ink is added to a beaker of water, the dye molecules become randomly dispersed throughout the water. This is an example of an increase in _______.

Accepted Answer

The answer of When a drop of ink is added...

Question 7

The energy in a system that exists due to position is called _______ energy.

Accepted Answer

The answer of The energy in a system that exists...

Question 8

The enzyme sucrase increases the rate at which sucrose is broken down into glucose and fructose. Sucrase works by

Accepted Answer

A)  increasing the amount of free energy of the reaction. 
B)  lowering the activation energy of the reaction. 
C)  decreasing the equilibrium constant of the reaction. 
D)  supplying energy to speed up the reaction. 
E)  changing the shape of the active site. 
A)  increasing the amount of free energy of the reaction. 
B)  lowering the activation energy of the reaction. 
C)  decreasing the equilibrium constant of the reaction. 
D)  supplying energy to speed up the reaction. 
E)  changing the shape of the active site.

Question 9

ATP hydrolysis is

Accepted Answer

A)  endergonic. 
B)  exergonic. 
C)  chemoautotrophic. 
D)  anabolic. 
E)  None of the above 
A)  endergonic. 
B)  exergonic. 
C)  chemoautotrophic. 
D)  anabolic. 
E)  None of the above

Question 10

The building up of molecules in a living system is known as _______; the breaking down of molecules in a living system is known as _______.

Accepted Answer

anabolism;

Question 11

How do competitive and noncompetitive enzyme inhibitors differ?

Accepted Answer

A)  Competitive inhibitors bind to the active site, whereas noncompetitive inhibitors change the shape of the active site. 
B)  Competitive inhibitors have a higher energy of activation than noncompetitive inhibitors have. 
C)  They function at different pH values. 
D)  Noncompetitive enzyme inhibitors contain magnesium, whereas competitive inhibitors contain iron. 
E)  Noncompetitive enzyme inhibitors are reversible, whereas competitive inhibitors are irreversible. 
A)  Competitive inhibitors bind to the active site, whereas noncompetitive inhibitors change the shape of the active site. 
B)  Competitive inhibitors have a higher energy of activation than noncompetitive inhibitors have. 
C)  They function at different pH values. 
D)  Noncompetitive enzyme inhibitors contain magnesium, whereas competitive inhibitors contain iron. 
E)  Noncompetitive enzyme inhibitors are reversible, whereas competitive inhibitors are irreversible.

Question 12

You fill two containers with identical amounts of reactants A and B and enzymes 1-4. In the reactions shown below, if product D inhibits enzyme 2 and product F is an allosteric stimulator of enzyme 1, what will be the final result if you add extra product D to the second container? (Assume that both containers are given enough time for the reactions to go to completion.)

Accepted Answer

A)  The concentration of product C will increase and there will be no change in product F concentration compared to the first container. 
B)  The concentration of reactants A and B will increase relative to the first container. 
C)  The concentration of product F will increase in the second container because more of D is converted back to C. 
D)  The concentration of products E and F will both increase in the second container, since D inhibits enzyme 2. 
E)  The concentration of product F will increase relative to the first container, since enzyme 2 will have been inhibited from converting as much of C into D. 
A)  The concentration of product C will increase and there will be no change in product F concentration compared to the first container. 
B)  The concentration of reactants A and B will increase relative to the first container. 
C)  The concentration of product F will increase in the second container because more of D is converted back to C. 
D)  The concentration of products E and F will both increase in the second container, since D inhibits enzyme 2. 
E)  The concentration of product F will increase relative to the first container, since enzyme 2 will have been inhibited from converting as much of C into D.

Question 13

Nerve gases such as Sarin and malathion

Accepted Answer

A)  block specific chemical transformations by inactivating specific enzymes. 
B)  have reversible effects on animals. 
C)  are proteins with a primary structure. 
D)  block the energy coupling cycle of ATP. 
E)  bond covalently to the active site of the enzyme. 
A)  block specific chemical transformations by inactivating specific enzymes. 
B)  have reversible effects on animals. 
C)  are proteins with a primary structure. 
D)  block the energy coupling cycle of ATP. 
E)  bond covalently to the active site of the enzyme.

Question 14

Competitive inhibitors of enzymes work by

Accepted Answer

A)  fitting into the active site. 
B)  fitting into a site other than the active site. 
C)  altering the shape of the enzyme. 
D)  changing the enzyme into an inactive form. 
E)  increasing the activation energy of the enzyme-catalyzed reaction. 
A)  fitting into the active site. 
B)  fitting into a site other than the active site. 
C)  altering the shape of the enzyme. 
D)  changing the enzyme into an inactive form. 
E)  increasing the activation energy of the enzyme-catalyzed reaction.

Question 15

Amylase is a digestive enzyme that breaks down starch and is secreted in the mouth of humans. Amylase functions well in the mouth but ceases to function once it hits the acidic stomach environment. Explain why amylase does not function in the stomach.

Accepted Answer

The pH optimum of amylase is approximate

Question 16

Enzymes of the acid-base catalysis type contain

Accepted Answer

A)  a metal ion bound to a side chain. 
B)  a prosthetic group. 
C)  a coenzyme. 
D)  acidic or basic amino acid side chains (R groups) in the active site. 
E)  a covalently activated active site. 
A)  a metal ion bound to a side chain. 
B)  a prosthetic group. 
C)  a coenzyme. 
D)  acidic or basic amino acid side chains (R groups) in the active site. 
E)  a covalently activated active site.

Question 17

Entropy

Accepted Answer

A)  is the total energy in a system. 
B)  tends to decrease the total energy in the universe. 
C)  when multiplied times the absolute temperature, is the useable energy in a system. 
D)  is related to the disorder or randomness of a system. 
E)  is represented in equations by the letter "H." 
A)  is the total energy in a system. 
B)  tends to decrease the total energy in the universe. 
C)  when multiplied times the absolute temperature, is the useable energy in a system. 
D)  is related to the disorder or randomness of a system. 
E)  is represented in equations by the letter "H."

Question 18

Coenzymes and cofactors, as well as prosthetic groups, assist enzyme function by

Accepted Answer

A)  stabilizing three-dimensional shape. 
B)  assisting with the binding of enzyme and substrate. 
C)  maintaining active sites in an active configuration. 
D)  reversibly binding to the enzyme to regulate the enzyme's activity. 
E)  a, b, and c only 
A)  stabilizing three-dimensional shape. 
B)  assisting with the binding of enzyme and substrate. 
C)  maintaining active sites in an active configuration. 
D)  reversibly binding to the enzyme to regulate the enzyme's activity. 
E)  a, b, and c only

Question 19

When an enzyme is heated until its three-dimensional structure is destroyed, the enzyme is said to be _______.

Accepted Answer

The answer of When an enzyme is heated until its...

Question 20

Although some enzymes consist entirely of one or more polypeptide chains, others possess a permanently bound nonprotein portion called a(n) _______.

Accepted Answer

The answer of Although some enzymes consist entirely of one...

Exam 8: Energy, Enzymes, and Metabolism

Which of the following statements about ATP is false?

End products of biosynthetic pathways often act to block the initial step in that pathway. This phenomenon is called

Allosteric inhibitors act by

Explain how free energy, total energy, temperature, and entropy are related.

The enzyme glucose oxidase binds the six-carbon sugar glucose and catalyzes its conversion to glucono-1,4-actone. Mannose is also a six-carbon sugar, but glucose oxidase cannot bind mannose. The specificity of glucose oxidase is based on the

When a drop of ink is added to a beaker of water, the dye molecules become randomly dispersed throughout the water. This is an example of an increase in _______.

The energy in a system that exists due to position is called _______ energy.

The enzyme sucrase increases the rate at which sucrose is broken down into glucose and fructose. Sucrase works by

ATP hydrolysis is

The building up of molecules in a living system is known as _______; the breaking down of molecules in a living system is known as _______.

How do competitive and noncompetitive enzyme inhibitors differ?

Nerve gases such as Sarin and malathion

Competitive inhibitors of enzymes work by

Amylase is a digestive enzyme that breaks down starch and is secreted in the mouth of humans. Amylase functions well in the mouth but ceases to function once it hits the acidic stomach environment. Explain why amylase does not function in the stomach.

Enzymes of the acid-base catalysis type contain

Entropy

Coenzymes and cofactors, as well as prosthetic groups, assist enzyme function by

When an enzyme is heated until its three-dimensional structure is destroyed, the enzyme is said to be _______.

Although some enzymes consist entirely of one or more polypeptide chains, others possess a permanently bound nonprotein portion called a(n) _______.

Studying Life

Small Molecules and the Chemistry of Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Signaling and Communication

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinent Dna and Biotechnology

Differential Gene Expression in Development

Development and Evolutionary Change

Evidence and Mechanisms of Evolution

Reconstructing and Using Phylogenies

Species and Their Formation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria and Archaea: the Prokaryotic Domains

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

Fungi: Recyclers, Pathogens, Parasites, and Plant Partners

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Animal Development

Neurons and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Function

Musculoskeletal Systems

Gas Exchange in Animals

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen

Animal Behavior

Ecology and the Distribution of Life

Population Ecology

Species Interaction and Coevolution

Community Ecology

Ecosystems and Global Ecology

Conservation Biology

Filters

The building up of molecules in a living system is known as _; the breaking down of molecules in a living system is known as _.