Question 1

-Refer to the graph. Which phrase best describes what it represents?

Accepted Answer

A) enzyme activity as a function of pH in a fairly neutral environment 
B) enzyme activity as a function of pH in a strongly acidic environment 
C) enzyme activity as a function of temperature 
D) enzyme activity as a function of pH in a strongly basic environment 
A) enzyme activity as a function of pH in a fairly neutral environment 
B) enzyme activity as a function of pH in a strongly acidic environment 
C) enzyme activity as a function of temperature 
D) enzyme activity as a function of pH in a strongly basic environment

Question 2

What does it mean when an enzyme is saturated?

Accepted Answer

A) It means the enzymes need more reactants. 
B) It means the enzymes have sufficient reactants available for optimal activity. 
C) It means the enzymes cannot continue to catalyze the reaction. 
D) It means the reaction is at equilibrium. 
A) It means the enzymes need more reactants. 
B) It means the enzymes have sufficient reactants available for optimal activity. 
C) It means the enzymes cannot continue to catalyze the reaction. 
D) It means the reaction is at equilibrium.

Question 3

Match each definition with the corresponding term.
-substrate

Accepted Answer

A) primary coupling agent in cellular reactions 
B) addition of a phosphate group to a target molecule 
C) product of the reaction interacts with an enzyme in a noncompetitive way to inhibit or enhance enzyme activity 
D) linking of an exergonic reaction with an endergonic reaction that allows a cell to drive a nonspontaneous reaction to completion 
E) series of chemical reactions where the products of one reaction are the reactants for a subsequent reaction
F)substance that facilitates a chemical reaction without itself being consumed by the reaction
G)energy needed to start a reaction, be it endergonic or exergonic
H)portion of the enzyme that binds to a reactant or reactants
I)state in which the rate of the forward reaction equals the rate of the reverse reaction
J)intermediate arrangement of unstable bonds between atoms that can proceed toward either the reactants or the products of a reaction
K)reactant molecule that binds to an enzyme 
A) primary coupling agent in cellular reactions 
B) addition of a phosphate group to a target molecule 
C) product of the reaction interacts with an enzyme in a noncompetitive way to inhibit or enhance enzyme activity 
D) linking of an exergonic reaction with an endergonic reaction that allows a cell to drive a nonspontaneous reaction to completion 
E) series of chemical reactions where the products of one reaction are the reactants for a subsequent reaction
F)substance that facilitates a chemical reaction without itself being consumed by the reaction
G)energy needed to start a reaction, be it endergonic or exergonic
H)portion of the enzyme that binds to a reactant or reactants
I)state in which the rate of the forward reaction equals the rate of the reverse reaction
J)intermediate arrangement of unstable bonds between atoms that can proceed toward either the reactants or the products of a reaction
K)reactant molecule that binds to an enzyme

Question 4

For each situation, choose the most appropriate term.
-digestion of a candy bar

Accepted Answer

A) endergonic 
B) exergonic 
C) equilibrium 
A) endergonic 
B) exergonic 
C) equilibrium

Question 5

Which of the following best illustrates the first law of thermodynamics by Niagara Falls?

Accepted Answer

A) Water at the top of the falls has high kinetic energy; as the water moves over the waterfall, its kinetic energy is converted into potential energy; when the water reaches the bottom of the waterfall, its potential energy is transformed into other types of energy: heat, sound, and mechanical energy. 
B) Water at the top of the falls has high potential energy; as the water moves over the waterfall, its potential energy is converted into kinetic energy; when the water reaches the bottom of the waterfall, its kinetic energy is transformed into other types of energy: heat, sound, and mechanical energy. 
C) Water at the top of the falls has high potential energy; as the water moves over the waterfall, its potential energy is converted into kinetic energy; when the water reaches the bottom of the waterfall, its kinetic energy is transformed into potential energy again. 
D) Water at the top of the falls has high potential energy; as the water moves over the waterfall, its potential energy is converted into kinetic energy; when the water reaches the bottom of the waterfall, its kinetic energy is lost. 
A) Water at the top of the falls has high kinetic energy; as the water moves over the waterfall, its kinetic energy is converted into potential energy; when the water reaches the bottom of the waterfall, its potential energy is transformed into other types of energy: heat, sound, and mechanical energy. 
B) Water at the top of the falls has high potential energy; as the water moves over the waterfall, its potential energy is converted into kinetic energy; when the water reaches the bottom of the waterfall, its kinetic energy is transformed into other types of energy: heat, sound, and mechanical energy. 
C) Water at the top of the falls has high potential energy; as the water moves over the waterfall, its potential energy is converted into kinetic energy; when the water reaches the bottom of the waterfall, its kinetic energy is transformed into potential energy again. 
D) Water at the top of the falls has high potential energy; as the water moves over the waterfall, its potential energy is converted into kinetic energy; when the water reaches the bottom of the waterfall, its kinetic energy is lost.

Question 6

Reactions that reach an equilibrium point are reversible.

Accepted Answer

A) True 
 B)False

Question 7

For each situation, choose the most appropriate term.
-a beaker of water sitting on a bench

Accepted Answer

A) endergonic 
B) exergonic 
C) equilibrium 
A) endergonic 
B) exergonic 
C) equilibrium

Question 8

Explain how temperature can affect enzyme activity.

Accepted Answer

Temperature affects kinetic energy as we

Question 9

Which of the following best describes how enzymes function?

Accepted Answer

A) by slowing the rate of some reactions and increasing the rate of other reactions 
B) by increasing the rate of a reaction 
C) by adding additional reactants to the system 
D) by changing the ?G of the reaction 
A) by slowing the rate of some reactions and increasing the rate of other reactions 
B) by increasing the rate of a reaction 
C) by adding additional reactants to the system 
D) by changing the ?G of the reaction

Question 10

Which reaction is likely to have more products than reactants when the reaction reaches equilibrium?

Accepted Answer

A)    G = -25 kcal/mol 
B)    G = -50 kcal/mol 
C)    G = -75 kcal/mol 
D)    G = -100 kcal/mol 
A)    G = -25 kcal/mol 
B)    G = -50 kcal/mol 
C)    G = -75 kcal/mol 
D)    G = -100 kcal/mol

Question 11

Which of the following is a correct pair based on their shared characteristics?

Accepted Answer

A) Earth and a closed system 
B) the universe and an open system 
C) an ocean and a closed system 
D) an ocean and an isolated system 
A) Earth and a closed system 
B) the universe and an open system 
C) an ocean and a closed system 
D) an ocean and an isolated system

Question 12

Which of the following best describes why bricks from a truck fall all over during a traffic accident?

Accepted Answer

A) The bricks have reached an equilibrium state. 
B) The bricks have reached a minimum entropy state. 
C) The bricks have reached a maximum free energy state. 
D) The bricks have reached a minimum free energy state. 
A) The bricks have reached an equilibrium state. 
B) The bricks have reached a minimum entropy state. 
C) The bricks have reached a maximum free energy state. 
D) The bricks have reached a minimum free energy state.

Question 13

Photomicrograph by Dr. Conly L. Rieder, East Greenbush, New York
-Which of the following hypotheses do you believe is best supported by the data in the graph?

Accepted Answer

A) The enzyme will completely denature at 38ºC. 
B) The enzyme will probably be inactive at a pH below 4.5. 
C) The enzyme has a cofactor. 
D) The enzyme's activity will drop at temperatures above 40ºC, and activity will likely be eliminated by 55ºC. 
A) The enzyme will completely denature at 38ºC. 
B) The enzyme will probably be inactive at a pH below 4.5. 
C) The enzyme has a cofactor. 
D) The enzyme's activity will drop at temperatures above 40ºC, and activity will likely be eliminated by 55ºC.

Question 14

Enzyme activity is increased by falling temperatures.

Accepted Answer

A) True 
 B)False

Question 15

Match each definition with the corresponding term.
-transition state

Accepted Answer

A) primary coupling agent in cellular reactions 
B) addition of a phosphate group to a target molecule 
C) product of the reaction interacts with an enzyme in a noncompetitive way to inhibit or enhance enzyme activity 
D) linking of an exergonic reaction with an endergonic reaction that allows a cell to drive a nonspontaneous reaction to completion 
E) series of chemical reactions where the products of one reaction are the reactants for a subsequent reaction
F)substance that facilitates a chemical reaction without itself being consumed by the reaction
G)energy needed to start a reaction, be it endergonic or exergonic
H)portion of the enzyme that binds to a reactant or reactants
I)state in which the rate of the forward reaction equals the rate of the reverse reaction
J)intermediate arrangement of unstable bonds between atoms that can proceed toward either the reactants or the products of a reaction
K)reactant molecule that binds to an enzyme 
A) primary coupling agent in cellular reactions 
B) addition of a phosphate group to a target molecule 
C) product of the reaction interacts with an enzyme in a noncompetitive way to inhibit or enhance enzyme activity 
D) linking of an exergonic reaction with an endergonic reaction that allows a cell to drive a nonspontaneous reaction to completion 
E) series of chemical reactions where the products of one reaction are the reactants for a subsequent reaction
F)substance that facilitates a chemical reaction without itself being consumed by the reaction
G)energy needed to start a reaction, be it endergonic or exergonic
H)portion of the enzyme that binds to a reactant or reactants
I)state in which the rate of the forward reaction equals the rate of the reverse reaction
J)intermediate arrangement of unstable bonds between atoms that can proceed toward either the reactants or the products of a reaction
K)reactant molecule that binds to an enzyme

Question 16

Which sentence best describes the situation that occurs when an enzyme and its substrate interact?

Accepted Answer

A) Just after substrate binding, the enzyme changes its shape (conformation) so that the active site becomes even more precise in its ability to bind the substrate. 
B) Just before substrate binding, the enzyme changes its shape (conformation) so that the active site becomes even more precise in its ability to bind the substrate. 
C) Just before substrate binding, the substrate changes its shape (conformation) so that the active site becomes even more precise in its ability to bind the enzyme. 
D) Just after substrate binding, the substrate changes its shape (conformation) so that the active site becomes even more precise in its ability to bind the enzyme. 
A) Just after substrate binding, the enzyme changes its shape (conformation) so that the active site becomes even more precise in its ability to bind the substrate. 
B) Just before substrate binding, the enzyme changes its shape (conformation) so that the active site becomes even more precise in its ability to bind the substrate. 
C) Just before substrate binding, the substrate changes its shape (conformation) so that the active site becomes even more precise in its ability to bind the enzyme. 
D) Just after substrate binding, the substrate changes its shape (conformation) so that the active site becomes even more precise in its ability to bind the enzyme.

Question 17

Suppose you conduct an experiment in the laboratory in which you add increasing amounts of substrate to a solution containing an enzyme and a pH buffer. You incubate the container at the optimal temperature for the enzyme. Each time you add more substrate, you measure the rate of the reaction. Also suppose that you graph the results such that the x-axis shows the substrate concentration and the y-axis shows the resulting reaction rate. What will you find over time?

Accepted Answer

A) The rate of the reaction will increase rapidly, taper off, and plateau. 
B) The resulting graph will be a perfect bell curve. 
C) The rate of the reaction will increase slowly, plateau, and then drop sharply back to zero. 
D) The rate of the reaction will proceed with a slope of 1 and continue in a linear fashion indefinitely or until you run out of reactants. 
A) The rate of the reaction will increase rapidly, taper off, and plateau. 
B) The resulting graph will be a perfect bell curve. 
C) The rate of the reaction will increase slowly, plateau, and then drop sharply back to zero. 
D) The rate of the reaction will proceed with a slope of 1 and continue in a linear fashion indefinitely or until you run out of reactants.

Question 18

Explain how a cell can use catabolic reactions to drive anabolic reactions, despite energy loss in the form of entropy and heat.

Accepted Answer

Cells use coupled reactions to harness t

Question 19

Which statement best describes the three types of systems?

Accepted Answer

A) An isolated system does not exchange energy or matter with its surroundings; a closed system exchanges only energy, but not matter with its surroundings; an open system exchanges both energy and matter with its surroundings. 
B) An isolated system does not exchange energy or matter with its surroundings; a closed system exchanges only matter, but not energy with its surroundings; an open system exchanges both energy and matter with its surroundings. 
C) An isolated system exchanges energy with its surroundings; a closed system exchanges only matter, but not energy with its surroundings; an open system exchanges both energy and matter with its surroundings. 
D) An isolated system exchanges energy with its surroundings; a closed system exchanges only energy, but not matter with its surroundings; an open system exchanges matter, but not energy with its surroundings. 
A) An isolated system does not exchange energy or matter with its surroundings; a closed system exchanges only energy, but not matter with its surroundings; an open system exchanges both energy and matter with its surroundings. 
B) An isolated system does not exchange energy or matter with its surroundings; a closed system exchanges only matter, but not energy with its surroundings; an open system exchanges both energy and matter with its surroundings. 
C) An isolated system exchanges energy with its surroundings; a closed system exchanges only matter, but not energy with its surroundings; an open system exchanges both energy and matter with its surroundings. 
D) An isolated system exchanges energy with its surroundings; a closed system exchanges only energy, but not matter with its surroundings; an open system exchanges matter, but not energy with its surroundings.

Question 20

Which of the following occurs when a reaction reaches equilibrium?

Accepted Answer

A) The rates of the forward and reverse reactions are equal. 
B) The chemical reactions cease. 
C) Entropy is no longer in the system. 
D) The concentration of reactants equals the concentration of products. 
A) The rates of the forward and reverse reactions are equal. 
B) The chemical reactions cease. 
C) Entropy is no longer in the system. 
D) The concentration of reactants equals the concentration of products.

Exam 4: Energy and Enzymes

-Refer to the graph. Which phrase best describes what it represents?

What does it mean when an enzyme is saturated?

Match each definition with the corresponding term. -substrate

For each situation, choose the most appropriate term. -digestion of a candy bar

Which of the following best illustrates the first law of thermodynamics by Niagara Falls?

Reactions that reach an equilibrium point are reversible.

For each situation, choose the most appropriate term. -a beaker of water sitting on a bench

Explain how temperature can affect enzyme activity.

Which of the following best describes how enzymes function?

Which reaction is likely to have more products than reactants when the reaction reaches equilibrium?

Which of the following is a correct pair based on their shared characteristics?

Which of the following best describes why bricks from a truck fall all over during a traffic accident?

Photomicrograph by Dr. Conly L. Rieder, East Greenbush, New York -Which of the following hypotheses do you believe is best supported by the data in the graph?

Enzyme activity is increased by falling temperatures.

Match each definition with the corresponding term. -transition state

Which sentence best describes the situation that occurs when an enzyme and its substrate interact?

Explain how a cell can use catabolic reactions to drive anabolic reactions, despite energy loss in the form of entropy and heat.

Which statement best describes the three types of systems?

Which of the following occurs when a reaction reaches equilibrium?

Light and Life

The Cell: an Overview

Defining Life and Its Origins

Cell Membranes and Signalling

Cellular Respiration

Photosynthesis

Cell Cycles

Genetic Recombination

Mendel, Genes, and Inheritance

Genes, Chromosomes, and Human Genetics

Dna Structure, Replication, and Organization

Gene Structure and Expression

Control of Gene Expression

Dna Technologies

Genomes and Proteomes

Evolution: the Development of the Theory

Microevolution: Changes Within Populations

Species and Macroevolution

Understanding the History of Life on Earth

Humans and Evolution

Bacteria and Archaea

Viruses, Viroids, and Prions: Infectious Biological Particles

Protists

Fungi

Plants

Diversity of Animals 1: Sponges, Radiata, Platyhelminthes, and Protostomes

Diversity of Animals 2: Deuterostomes: Vertebrates and Their Closest Relatives

Population Ecology

Population Interactions and Community Ecology

Ecosystems

Conservation of Biodiversity

Putting Selection to Work

Organization of the Plant Body

Transport in Plants

Reproduction and Development in Flowering Plants

Plant Nutrition

Plant Signals and Responses to the Environment

Introduction to Animal Organization and Physiology

Transport in Animals: the Circulatory System

Reproduction in Animals

Animal Development

Control of Animal Processes: Neural Control

Control of Animal Processes: Neural Control

Control of Animal Processes: Neural Integration

Muscles, Skeletons, and Body Movements

Animal Behaviour

Animal Nutrition

Gas Exchange: the Respiratory System

Regulating the Internal Environment

Defences Against Disease

Conservation and Evolutionary Physiology

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