Question 1

Why is using heat to speed up biological reactions problematic?

Accepted Answer

Although increasing the temper

Question 2

Allosteric inhibitors are often ____.

Accepted Answer

A)  substrates of the reactions they regulate 
B)  products of the reactions that they regulate 
C)  charged amino acids in the active site 
D)  large, complex organic molecules 
E)  competitive inhibitors 
A)  substrates of the reactions they regulate 
B)  products of the reactions that they regulate 
C)  charged amino acids in the active site 
D)  large, complex organic molecules 
E)  competitive inhibitors

Question 3

Approximately how many ATP molecules are hydrolyzed and resynthesized each second in a typical cell?

Accepted Answer

A)  100 
B)  10,000 
C)  100,000 
D)  10,000,000 
E)  100,000,000 
A)  100 
B)  10,000 
C)  100,000 
D)  10,000,000 
E)  100,000,000

Question 4

When an enzyme-catalyzed reaction reaches equilibrium ____.

Accepted Answer

A)  the enzymes are now inhibited 
B)  the chemical reactions cease 
C)  the rate of the forward and reverse reactions are equal 
D)  the concentration of reactants equals the concentration of products 
E)  ATP is no longer required to drive the reaction 
A)  the enzymes are now inhibited 
B)  the chemical reactions cease 
C)  the rate of the forward and reverse reactions are equal 
D)  the concentration of reactants equals the concentration of products 
E)  ATP is no longer required to drive the reaction

Question 5

An exergonic reaction will have a ____.

Accepted Answer

A)  negative change in kinetic energy 
B)  positive change in enthalpy 
C)  negative change in entropy 
D)  DG = 0 
E)  negative change in free energy 
A)  negative change in kinetic energy 
B)  positive change in enthalpy 
C)  negative change in entropy 
D)  DG = 0 
E)  negative change in free energy

Question 6

During every energy transformation, it can be said that ____.

Accepted Answer

A)  the entropy of the universe increases 
B)  the entropy of the universe decreases 
C)  there is an increase in the free energy of the universe 
D)  there is a change in the total energy of the universe 
E)  the system becomes more organized 
A)  the entropy of the universe increases 
B)  the entropy of the universe decreases 
C)  there is an increase in the free energy of the universe 
D)  there is a change in the total energy of the universe 
E)  the system becomes more organized

Question 7

Coenzymes that bind tightly to enzymes are called ____.

Accepted Answer

A)  cofactors 
B)  appendages 
C)  regulatory groups 
D)  prosthetic groups 
E)  magnetic groups 
A)  cofactors 
B)  appendages 
C)  regulatory groups 
D)  prosthetic groups 
E)  magnetic groups

Question 8

You modify the primary sequence of an enzyme in a region that will be the active site when the protein is properly folded. What is the predicted outcome of this change?

Accepted Answer

A)  The enzyme will not bind to the substrate properly. 
B)  The enzyme will not be able to bind an allosteric inhibitor. 
C)  The enzyme will have an increased rate of activity. 
D)  There will be no change in the enzyme's function. 
E)  The enzyme will bind the substrate but not be able to release the products. 
A)  The enzyme will not bind to the substrate properly. 
B)  The enzyme will not be able to bind an allosteric inhibitor. 
C)  The enzyme will have an increased rate of activity. 
D)  There will be no change in the enzyme's function. 
E)  The enzyme will bind the substrate but not be able to release the products.

Question 9

Eating and digesting a candy bar for energy during a sports event is a good example of ____.

Accepted Answer

A)  catabolism 
B)  anabolism 
C)  converting kinetic energy into potential energy 
D)  metabolism 
E)  converting heat energy into chemical energy 
A)  catabolism 
B)  anabolism 
C)  converting kinetic energy into potential energy 
D)  metabolism 
E)  converting heat energy into chemical energy

Question 10

Enzymes function primarily by ____.

Accepted Answer

A)  forcing the reactants into an altered environment which in turn creates a change in the free energy of the reactants relative to the products 
B)  altering the equilibrium point of a particular reaction to favor the formation of products 
C)  increasing the probability that the reactants will come into close proximity to each other in the proper orientation for forming the transition state molecule 
D)  removing reactants from solution in a set ratio to increase the chances of the remaining individual reactants interacting with each other 
E)  changing the ratio of reactants to products so that the forward reaction is favored 
A)  forcing the reactants into an altered environment which in turn creates a change in the free energy of the reactants relative to the products 
B)  altering the equilibrium point of a particular reaction to favor the formation of products 
C)  increasing the probability that the reactants will come into close proximity to each other in the proper orientation for forming the transition state molecule 
D)  removing reactants from solution in a set ratio to increase the chances of the remaining individual reactants interacting with each other 
E)  changing the ratio of reactants to products so that the forward reaction is favored

Question 11

Reversible reactions in a cell rarely reach equilibrium because ____.

Accepted Answer

A)  the products are generally reactants in other reactions and are thus immediately used 
B)  a cell at equilibrium is dead 
C)  they are highly regulated to prevent overuse of reactants 
D)  cells have no way of measuring the relative ratios of reactants and products 
E)  conditions in the cell change too rapidly for any reaction to ever reach equilibrium 
A)  the products are generally reactants in other reactions and are thus immediately used 
B)  a cell at equilibrium is dead 
C)  they are highly regulated to prevent overuse of reactants 
D)  cells have no way of measuring the relative ratios of reactants and products 
E)  conditions in the cell change too rapidly for any reaction to ever reach equilibrium

Question 12

Which system is considered an open system?

Accepted Answer

A)  a human 
B)  a thermos 
C)  a wine keg 
D)  a greenhouse 
E)  the Earth 
A)  a human 
B)  a thermos 
C)  a wine keg 
D)  a greenhouse 
E)  the Earth

Question 13

Figure 6.4
Answer the question by using the accompanying graph. The optimal pH for enzyme 2 is ____.

Accepted Answer

A)  2 
B)  3 
C)  4 
D)  7 
E)  8 
A)  2 
B)  3 
C)  4 
D)  7 
E)  8

Question 14

What is the effect of the proper balance of ionized and deionized amino acids in an enzyme?

Accepted Answer

A)  optimal enzyme efficiency 
B)  an acid/base reaction required for synthesis 
C)  the binding of substrates that otherwise would not fit 
D)  an electronic current to provide the energy for the reaction 
E)  increased salt concentration required for the chemical reaction to occur 
A)  optimal enzyme efficiency 
B)  an acid/base reaction required for synthesis 
C)  the binding of substrates that otherwise would not fit 
D)  an electronic current to provide the energy for the reaction 
E)  increased salt concentration required for the chemical reaction to occur

Question 15

Enzymes alter the equilibrium point of a reaction.

Accepted Answer

A) True 
 B)False

Question 16

If a reaction is spontaneous, then ΔG is ____ and the reaction is ____.

Accepted Answer

A)  negative; endergonic 
B)  negative; exergonic 
C)  zero; endergonic 
D)  positive; endergonic 
E)  positive; exergonic 
A)  negative; endergonic 
B)  negative; exergonic 
C)  zero; endergonic 
D)  positive; endergonic 
E)  positive; exergonic

Question 17

Harry Noller's experiments in which he extracted the ribosomal proteins and found that RNA molecules could catalyze protein synthesis had one major flaw. What was the flaw?

Accepted Answer

A)  The extraction process may have altered the RNA molecules. 
B)  Protein synthesis may have occurred prior to extraction. 
C)  Coenzymes, which were not extracted, might have been responsible for the reaction. 
D)  The extraction process may have altered the pH of the environment. 
E)  Undetectable amounts of protein may have remained. 
A)  The extraction process may have altered the RNA molecules. 
B)  Protein synthesis may have occurred prior to extraction. 
C)  Coenzymes, which were not extracted, might have been responsible for the reaction. 
D)  The extraction process may have altered the pH of the environment. 
E)  Undetectable amounts of protein may have remained.

Question 18

Figure 6.1
What can be inferred from the accompanying graph?

Accepted Answer

A)  This reaction is endergonic, with a positive ΔG. 
B)  This reaction is endergonic, with a negative ΔG. 
C)  This reaction is exergonic, with a positive ΔG. 
D)  This reaction is exergonic, with a negative ΔG. 
E)  There is not enough information to make a determination. 
A)  This reaction is endergonic, with a positive ΔG. 
B)  This reaction is endergonic, with a negative ΔG. 
C)  This reaction is exergonic, with a positive ΔG. 
D)  This reaction is exergonic, with a negative ΔG. 
E)  There is not enough information to make a determination.

Question 19

If an enzyme is saturated, ____.

Accepted Answer

A)  it cannot continue to catalyze the reaction 
B)  the reaction is at equilibrium 
C)  the rate of the reaction will slow and the reaction will stop 
D)  it recruits more reactants 
E)  the reaction is being catalyzed at the maximum rate 
A)  it cannot continue to catalyze the reaction 
B)  the reaction is at equilibrium 
C)  the rate of the reaction will slow and the reaction will stop 
D)  it recruits more reactants 
E)  the reaction is being catalyzed at the maximum rate

Question 20

A child swinging on a swing utilizes which type(s) of energy?

Accepted Answer

A)  kinetic energy only because the child is in constant motion 
B)  potential energy only, because the child has to invest energy to get the swing to move 
C)  chemical energy only, because it is the child's metabolism that powers the muscles that make the swing move 
D)  kinetic and potential energy only, but in constantly changing ratios: when changing direction, it is pure potential energy; at the bottom of the arc, it is pure kinetic energy 
E)  kinetic, potential, and chemical energy: the child powers the swing with chemical energy in the muscle, cells and the swing moves like a pendulum with changing ratios of kinetic and potential energy. 
A)  kinetic energy only because the child is in constant motion 
B)  potential energy only, because the child has to invest energy to get the swing to move 
C)  chemical energy only, because it is the child's metabolism that powers the muscles that make the swing move 
D)  kinetic and potential energy only, but in constantly changing ratios: when changing direction, it is pure potential energy; at the bottom of the arc, it is pure kinetic energy 
E)  kinetic, potential, and chemical energy: the child powers the swing with chemical energy in the muscle, cells and the swing moves like a pendulum with changing ratios of kinetic and potential energy.

Exam 6: Energy, Enzymes, and Biological Reactions

Why is using heat to speed up biological reactions problematic?

Allosteric inhibitors are often ____.

Approximately how many ATP molecules are hydrolyzed and resynthesized each second in a typical cell?

When an enzyme-catalyzed reaction reaches equilibrium ____.

An exergonic reaction will have a ____.

During every energy transformation, it can be said that ____.

Coenzymes that bind tightly to enzymes are called ____.

You modify the primary sequence of an enzyme in a region that will be the active site when the protein is properly folded. What is the predicted outcome of this change?

Eating and digesting a candy bar for energy during a sports event is a good example of ____.

Enzymes function primarily by ____.

Reversible reactions in a cell rarely reach equilibrium because ____.

Which system is considered an open system?

Figure 6.4 Answer the question by using the accompanying graph. The optimal pH for enzyme 2 is ____.

What is the effect of the proper balance of ionized and deionized amino acids in an enzyme?

Enzymes alter the equilibrium point of a reaction.

If a reaction is spontaneous, then ΔG is ____ and the reaction is ____.

Harry Noller's experiments in which he extracted the ribosomal proteins and found that RNA molecules could catalyze protein synthesis had one major flaw. What was the flaw?

Figure 6.1 What can be inferred from the accompanying graph?

If an enzyme is saturated, ____.

A child swinging on a swing utilizes which type(s) of energy?

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

Filters

If a reaction is spontaneous, then ΔG is and the reaction is .