Question 1

Figure 6.2
Answer the question using the accompanying graph. Which portion of the graph shows the activation energy in the presence of enzyme?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  W + X 
E)  Y + Z 
A)  A 
B)  B 
C)  C 
D)  W + X 
E)  Y + Z

Question 2

What happens when an enzyme is bound by an allosteric activator?

Accepted Answer

A)  The enzyme transitions from an activate state to an inactive state. 
B)  The enzyme transitions from a low affinity state to a high affinity state. 
C)  The enzyme transitions from a high affinity state to a low affinity state. 
D)  The enzyme can now bind to the cofactors necessary for the reaction. 
E)  The enzyme can no longer bind to inhibitors. 
A)  The enzyme transitions from an activate state to an inactive state. 
B)  The enzyme transitions from a low affinity state to a high affinity state. 
C)  The enzyme transitions from a high affinity state to a low affinity state. 
D)  The enzyme can now bind to the cofactors necessary for the reaction. 
E)  The enzyme can no longer bind to inhibitors.

Question 3

If an enzyme's optimal temperature is 37°C, then the enzyme ____.

Accepted Answer

A)  has a cofactor 
B)  is likely to catalyze the reaction at the same rate at 30°C 
C)  will probably be inactive at a pH below 4.5 
D)  will completely denature at 38°C 
E)  activity will drop at temperatures above 37°C and likely be eliminated by 60°C 
A)  has a cofactor 
B)  is likely to catalyze the reaction at the same rate at 30°C 
C)  will probably be inactive at a pH below 4.5 
D)  will completely denature at 38°C 
E)  activity will drop at temperatures above 37°C and likely be eliminated by 60°C

Question 4

Where does the energy for ATP synthesis come from?

Accepted Answer

A)  anabolism of complex molecules into simpler molecules 
B)  catabolism of complex molecules into simpler molecules 
C)  anabolism of simple molecules into complex molecules 
D)  catabolism of simple molecules into complex molecules 
E)  anabolism of complex molecules directly into ATP 
A)  anabolism of complex molecules into simpler molecules 
B)  catabolism of complex molecules into simpler molecules 
C)  anabolism of simple molecules into complex molecules 
D)  catabolism of simple molecules into complex molecules 
E)  anabolism of complex molecules directly into ATP

Question 5

Match between columns
                        Premises: a reaction where DG is negative
a dead cell
the rate of synthesis equals the rate of degradation
protein synthesis
digestion of a candy bar
a reaction where DG is positive

Accepted Answer

The Answer of exergonic and equilibrium and endergonic is...

Question 6

Figure 6.4
Answer the question by using the accompanying graph. If all three enzymes catalyze the same reaction and your experimental conditions require a pH of 8, which enzyme would you choose?

Accepted Answer

A)  enzyme 1 
B)  enzyme 2 
C)  enzyme 3 
D)  either enzyme 2 or 3 
E)  both enzymes 2 and 3 
A)  enzyme 1 
B)  enzyme 2 
C)  enzyme 3 
D)  either enzyme 2 or 3 
E)  both enzymes 2 and 3

Question 7

How does the cell overcome inhibition from irreversible inhibitors?

Accepted Answer

A)  by binding a second inhibitor, which forces the enzyme's conformation to dislodge the first inhibitor 
B)  by phosphorylating the enzyme, altering the enzyme's conformation to dislodge the inhibitor 
C)  by altering the cellular pH, which will decrease the bonding between the enzyme and the inhibitor 
D)  by degrading the enzyme-inhibitor complex and generating new enzyme 
E)  by upregulating the expression of other enzymes with similar catalytic functions 
A)  by binding a second inhibitor, which forces the enzyme's conformation to dislodge the first inhibitor 
B)  by phosphorylating the enzyme, altering the enzyme's conformation to dislodge the inhibitor 
C)  by altering the cellular pH, which will decrease the bonding between the enzyme and the inhibitor 
D)  by degrading the enzyme-inhibitor complex and generating new enzyme 
E)  by upregulating the expression of other enzymes with similar catalytic functions

Question 8

Reactions that reach an equilibrium point are reversible .

Accepted Answer

A) True 
 B)False

Question 9

How did Zhang and Cech purify the RNA molecules that were able to catalyze the linkage between two amino acids?

Accepted Answer

A)  passing the reaction mixture through a column that binds biotin 
B)  passing the reaction mixture through a column that binds all proteins 
C)  passing the reaction mixture through a column that binds RNA 
D)  centrifuging the reaction mixture to concentrate the proteins 
E)  centrifuging the reaction mixture to concentrate the RNA molecules 
A)  passing the reaction mixture through a column that binds biotin 
B)  passing the reaction mixture through a column that binds all proteins 
C)  passing the reaction mixture through a column that binds RNA 
D)  centrifuging the reaction mixture to concentrate the proteins 
E)  centrifuging the reaction mixture to concentrate the RNA molecules

Question 10

Why is energy defined as "the capacity to do work"?

Accepted Answer

Energy cannot be directly measured or we

Question 11

What is the difference between cofactors and coenzymes?

Accepted Answer

A)  Cofactors are not necessary for enzyme function, but coenzymes are. 
B)  Cofactors can be inorganic or organic, but coenzymes are always inorganic. 
C)  Cofactors can be inorganic or organic; coenzymes are organic cofactors. 
D)  Cofactors are always vitamins; coenzymes are always ions. 
E)  Cofactors help with essential metabolic reactions; coenzymes assist with nonessential metabolic reactions. 
A)  Cofactors are not necessary for enzyme function, but coenzymes are. 
B)  Cofactors can be inorganic or organic, but coenzymes are always inorganic. 
C)  Cofactors can be inorganic or organic; coenzymes are organic cofactors. 
D)  Cofactors are always vitamins; coenzymes are always ions. 
E)  Cofactors help with essential metabolic reactions; coenzymes assist with nonessential metabolic reactions.

Question 12

In competitive inhibition, the ____.

Accepted Answer

A)  products block the active site of the enzyme 
B)  products bind to a site other than the active site of the enzyme and block enzyme activity indirectly 
C)  substrate and cofactors compete for the active site 
D)  inhibitor binds to and directly blocks the active site of the enzyme 
E)  inhibitor binds to the enzyme at a site other than its active site 
A)  products block the active site of the enzyme 
B)  products bind to a site other than the active site of the enzyme and block enzyme activity indirectly 
C)  substrate and cofactors compete for the active site 
D)  inhibitor binds to and directly blocks the active site of the enzyme 
E)  inhibitor binds to the enzyme at a site other than its active site

Question 13

The first law of thermodynamics states that the total disorder of a system always increases.

Accepted Answer

A) True 
 B)False

Question 14

Because of some of the problems with explaining how the first RNA organisms originated, an alternative possibility has been proposed in which ____.

Accepted Answer

A)  proteins and RNA evolved simultaneously 
B)  DNA existed before RNA 
C)  lipids functioned as enzymes 
D)  a different form of life existed before the RNA world 
E)  viruses functioned as carriers for RNA 
A)  proteins and RNA evolved simultaneously 
B)  DNA existed before RNA 
C)  lipids functioned as enzymes 
D)  a different form of life existed before the RNA world 
E)  viruses functioned as carriers for RNA

Question 15

If a reaction is endergonic, what can we infer about the reaction?

Accepted Answer

A)  ΔH must be positive. 
B)  ΔH must be negative. 
C)  ΔG must be positive. 
D)  ΔG must be negative. 
E)  ΔS must be positive. 
A)  ΔH must be positive. 
B)  ΔH must be negative. 
C)  ΔG must be positive. 
D)  ΔG must be negative. 
E)  ΔS must be positive.

Question 16

Although energy cannot be created or destroyed, energy transformations are not 100% efficient. Why?

Accepted Answer

A)  Energy is lost as an increase in heat. 
B)  Energy is lost as an increase in entropy. 
C)  Energy is lost as a change in free energy. 
D)  Energy is lost as a decrease in heat. 
E)  Energy is lost as a decrease in entropy. 
A)  Energy is lost as an increase in heat. 
B)  Energy is lost as an increase in entropy. 
C)  Energy is lost as a change in free energy. 
D)  Energy is lost as a decrease in heat. 
E)  Energy is lost as a decrease in entropy.

Question 17

The ultimate fate of the energy used by organisms is ____.

Accepted Answer

A)  conversion into heat 
B)  transmission onto offspring 
C)  to be recycled repeatedly without loss 
D)  to be recycled as metabolic energy 
E)  move into the environment by conduction 
A)  conversion into heat 
B)  transmission onto offspring 
C)  to be recycled repeatedly without loss 
D)  to be recycled as metabolic energy 
E)  move into the environment by conduction

Question 18

Which system is considered a closed system?

Accepted Answer

A)  a human 
B)  a gas-powered automobile 
C)  a single-celled organism 
D)  a propane furnace 
E)  the Earth 
A)  a human 
B)  a gas-powered automobile 
C)  a single-celled organism 
D)  a propane furnace 
E)  the Earth

Question 19

Figure 6.2
Answer the question using the accompanying graph. Which portion of the graph shows the activation energy in the absence of enzyme?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  W + X 
E)  Y + Z 
A)  A 
B)  B 
C)  C 
D)  W + X 
E)  Y + Z

Question 20

Which equation is used to calculate the free energy associated with a reaction?

Accepted Answer

A)  ΔG = ΔH-TΔS 
B)  ΔG = ΔH+TΔS 
C)  ΔG = - ΔH+TΔS 
D)  ΔG = ΔS+TΔH 
E)  ΔG = -ΔS-TΔH 
A)  ΔG = ΔH-TΔS 
B)  ΔG = ΔH+TΔS 
C)  ΔG = - ΔH+TΔS 
D)  ΔG = ΔS+TΔH 
E)  ΔG = -ΔS-TΔH

Exam 6: Energy, Enzymes, and Biological Reactions

Figure 6.2 Answer the question using the accompanying graph. Which portion of the graph shows the activation energy in the presence of enzyme?

What happens when an enzyme is bound by an allosteric activator?

If an enzyme's optimal temperature is 37°C, then the enzyme ____.

Where does the energy for ATP synthesis come from?

Figure 6.4 Answer the question by using the accompanying graph. If all three enzymes catalyze the same reaction and your experimental conditions require a pH of 8, which enzyme would you choose?

How does the cell overcome inhibition from irreversible inhibitors?

Reactions that reach an equilibrium point are reversible .

How did Zhang and Cech purify the RNA molecules that were able to catalyze the linkage between two amino acids?

Why is energy defined as "the capacity to do work"?

What is the difference between cofactors and coenzymes?

In competitive inhibition, the ____.

The first law of thermodynamics states that the total disorder of a system always increases.

Because of some of the problems with explaining how the first RNA organisms originated, an alternative possibility has been proposed in which ____.

If a reaction is endergonic, what can we infer about the reaction?

Although energy cannot be created or destroyed, energy transformations are not 100% efficient. Why?

The ultimate fate of the energy used by organisms is ____.

Which system is considered a closed system?

Figure 6.2 Answer the question using the accompanying graph. Which portion of the graph shows the activation energy in the absence of enzyme?

Which equation is used to calculate the free energy associated with a reaction?

Introduction to Biological Concepts and Research

Life, Chemistry, and Water

Biological Molecules: the Carbon Compounds of Life

Cells

Membranes and Transport

Cellular Respiration: Harvesting Chemical Energy

Photosynthesis

Cell Communication

Cell Division and Mitosis

Meiosis: the Cellular Basis of Sexual Reproduction

Mendel, Genes, and Inheritance

Genes, Chromosomes, and Human Genetics

Dna Structure, Replication, and Organization

Gene Expression: From Dna to Protein

Regulation of Gene Expression

Bacterial and Viral Genetics

Dna Technology: Making and Using Genetically Altered Organisms, and Other Applications

Genomes and Proteomes

The Development of Evolutionary Thought

Microevolution: Genetic Changes Within Populations

Speciation

Paleobiology and Macroevolution

Systematic Biology: Phylogeny and Classification

The Origin of Life

Prokaryotes and Viruses

Protists

Seedless Plants

Seed Plants

Fungi

Animal Phylogeny, Acoelomates, and Protostomes

Deuterostomes: Vertebrates and Their Closest Relatives

The Plant Body

Transport in Plants

Plant Nutrition

Reproduction and Development in Flowering Plants

Plant Signals and Responses to the Environment

Introduction to Animal Organization and Physiology

Information Flow and the Neuron

Nervous Systems

Sensory Systems

The Endocrine System

Muscles, Bones, and Body Movements

The Circulatory System

Defenses Against Disease

Gas Exchange: the Respiratory System

Digestive Systems and Animal Nutrition

Regulating the Internal Environment: Osmoregulation, Excretion, and Thermoregulation

Animal Reproduction

Animal Development

Ecology and the Biosphere

Population Ecology

Population Interactions and Community Ecology

Ecosystems

Biodiversity and Conservation Biology

Animal Behavior

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