Question 1

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 2

A nucleotide in DNA is made up of

Accepted Answer

A)  four bases. 
B)  a base plus a ribose sugar. 
C)  a base plus a deoxyribose sugar plus phosphate. 
D)  a sugar plus a phosphate. 
E)  a sugar and a base. 
A)  four bases. 
B)  a base plus a ribose sugar. 
C)  a base plus a deoxyribose sugar plus phosphate. 
D)  a sugar plus a phosphate. 
E)  a sugar and a base.

Question 3

The molecules that are acted on by an enzyme are called

Accepted Answer

A)  products. 
B)  substrates. 
C)  carriers. 
D)  prosthetics. 
E)  effectors. 
A)  products. 
B)  substrates. 
C)  carriers. 
D)  prosthetics. 
E)  effectors.

Question 4

All of the following contribute to the overall structure of proteins except

Accepted Answer

A)  charge differences between R groups. 
B)  disulfide bond formation between glycines. 
C)  interactions between R groups and the environment. 
D)  the N-H from the peptide backbone. 
E)  the C=O groups from the peptide backbone. 
A)  charge differences between R groups. 
B)  disulfide bond formation between glycines. 
C)  interactions between R groups and the environment. 
D)  the N-H from the peptide backbone. 
E)  the C=O groups from the peptide backbone.

Question 5

Leucine and valine have side chains consisting entirely of C and H;therefore,the side chains

Accepted Answer

A)  are hydrophilic. 
B)  are nonpolar. 
C)  contain sulfur atoms. 
D)  are electrically charged. 
E)  form only left-hand isomers. 
A)  are hydrophilic. 
B)  are nonpolar. 
C)  contain sulfur atoms. 
D)  are electrically charged. 
E)  form only left-hand isomers.

Question 6

The inhibition of enzyme activity by noncompetitive inhibitors can be reduced

Accepted Answer

A)  by a decrease in the concentration of allosteric enzymes. 
B)  by a decrease in the concentration of substrate. 
C)  by an increase in the concentration of a competitive inhibitor. 
D)  by an increase in the concentration of substrate. 
E)  only by release of the inhibitors from the enzyme. 
A)  by a decrease in the concentration of allosteric enzymes. 
B)  by a decrease in the concentration of substrate. 
C)  by an increase in the concentration of a competitive inhibitor. 
D)  by an increase in the concentration of substrate. 
E)  only by release of the inhibitors from the enzyme.

Question 7

The rate of a chemical reaction in a cell is the measure of how

Accepted Answer

A)  often the reaction occurs. 
B)  quickly the substrates are converted to product. 
C)  much energy must be added for the reaction to occur. 
D)  much activation energy is required for the reaction to occur. 
E)  easily the reaction is inhibited. 
A)  often the reaction occurs. 
B)  quickly the substrates are converted to product. 
C)  much energy must be added for the reaction to occur. 
D)  much activation energy is required for the reaction to occur. 
E)  easily the reaction is inhibited.

Question 8

The maximum possible rate of an enzyme reaction that is influenced by a competitive inhibitor depends on the concentration of

Accepted Answer

A)  hydrogen. 
B)  substrate. 
C)  product. 
D)  enzyme. 
E)  free energy. 
A)  hydrogen. 
B)  substrate. 
C)  product. 
D)  enzyme. 
E)  free energy.

Question 9

Which solution is least likely to denature an enzyme?

Accepted Answer

A)  Urea 
B)  Acetic acid 
C)  Distilled water 
D)  Boiling water 
E)  Mercaptoethanol 
A)  Urea 
B)  Acetic acid 
C)  Distilled water 
D)  Boiling water 
E)  Mercaptoethanol

Question 10

The active site of an enzyme

Accepted Answer

A)  never changes shape. 
B)  forms no chemical bonds with substrates. 
C)  determines,by its structure,the specificity of the enzyme. 
D)  looks like a lump projecting from the surface of the enzyme. 
E)  changes the $\Delta$ G of the reaction. 
A)  never changes shape. 
B)  forms no chemical bonds with substrates. 
C)  determines,by its structure,the specificity of the enzyme. 
D)  looks like a lump projecting from the surface of the enzyme. 
E)  changes the $\Delta$ G of the reaction.

Question 11

The sides of the "ladder" that makes up a nucleic acid molecule are made of

Accepted Answer

A)  nitrogenous bases. 
B)  pentose sugars and phosphate groups. 
C)  purines. 
D)  pyrimidines. 
E)  nucleosides. 
A)  nitrogenous bases. 
B)  pentose sugars and phosphate groups. 
C)  purines. 
D)  pyrimidines. 
E)  nucleosides.

Question 12

Aspartate and glutamate have side chains terminating in carboxyl groups;therefore,they

Accepted Answer

A)  are hydrophobic. 
B)  have sulfur atoms in their side chains. 
C)  have electrically charged side chains. 
D)  are nonpolar. 
E)  form only left-hand isomers. 
A)  are hydrophobic. 
B)  have sulfur atoms in their side chains. 
C)  have electrically charged side chains. 
D)  are nonpolar. 
E)  form only left-hand isomers.

Question 13

Which statement about DNA and RNA is true?

Accepted Answer

A)  DNA is single-stranded and RNA is double-stranded. 
B)  DNA is only informational and RNA is only catalytic. 
C)  DNA contains deoxyribose and RNA contains ribose. 
D)  DNA is transcribed and RNA is replicated. 
E)  DNA contains uracil (U)and RNA contains thymine (T). 
A)  DNA is single-stranded and RNA is double-stranded. 
B)  DNA is only informational and RNA is only catalytic. 
C)  DNA contains deoxyribose and RNA contains ribose. 
D)  DNA is transcribed and RNA is replicated. 
E)  DNA contains uracil (U)and RNA contains thymine (T).

Question 14

The addition of the competitive inhibitor mevinolin slows the reaction HMG-CoA $\rightarrow$mevalonate,which is catalyzed by the enzyme HMG-CoA reductase.The effects of mevinolin would be overcome and the rate of the reaction increased by

Accepted Answer

A)  adding more mevalonate. 
B)  adding more HMG-CoA. 
C)  lowering the temperature of the reaction. 
D)  adding a prosthetic group. 
E)  lowering the rate constant of the reaction. 
A)  adding more mevalonate. 
B)  adding more HMG-CoA. 
C)  lowering the temperature of the reaction. 
D)  adding a prosthetic group. 
E)  lowering the rate constant of the reaction.

Question 15

The amino acid lysine

Accepted Answer

A)  is found in all proteins. 
B)  has a negatively charged side chain. 
C)  has a hydrophobic side chain. 
D)  has a hydrophilic side chain. 
E)  is identical to the amino acid leucine. 
A)  is found in all proteins. 
B)  has a negatively charged side chain. 
C)  has a hydrophobic side chain. 
D)  has a hydrophilic side chain. 
E)  is identical to the amino acid leucine.

Question 16

The binding of substrate to enzyme creates a(n)

Accepted Answer

A)  transition state. 
B)  activation groove. 
C)  catalyst. 
D)  enzyme-substrate complex. 
E)  energy barrier. 
A)  transition state. 
B)  activation groove. 
C)  catalyst. 
D)  enzyme-substrate complex. 
E)  energy barrier.

Question 17

All of the following will increase the rate of conversion of reactant A to product B in the presence of enzyme C except

Accepted Answer

A)  an increase in enzyme concentration. 
B)  an increase in temperature to the optimum for the reaction. 
C)  an increase in substrate concentration. 
D)  the addition of nonbiological catalyst F,which can carry out the same reaction. 
E)  the addition of D,which can compete with A for binding on the active site. 
A)  an increase in enzyme concentration. 
B)  an increase in temperature to the optimum for the reaction. 
C)  an increase in substrate concentration. 
D)  the addition of nonbiological catalyst F,which can carry out the same reaction. 
E)  the addition of D,which can compete with A for binding on the active site.

Question 18

The quaternary structure of a protein

Accepted Answer

A)  consists of exactly four subunits-hence the name quaternary. 
B)  is unrelated to the function of the protein. 
C)  cannot change. 
D)  is determined mostly by covalent bonds. 
E)  depends on the primary structures of the subunits. 
A)  consists of exactly four subunits-hence the name quaternary. 
B)  is unrelated to the function of the protein. 
C)  cannot change. 
D)  is determined mostly by covalent bonds. 
E)  depends on the primary structures of the subunits.

Question 19

When organisms are adapted to movement between different environments,they sometimes synthesize variations of existing enzymes,which are called

Accepted Answer

A)  coenzymes. 
B)  abzymes. 
C)  isozymes. 
D)  effectors. 
E)  activators. 
A)  coenzymes. 
B)  abzymes. 
C)  isozymes. 
D)  effectors. 
E)  activators.

Question 20

If there is an exposed purine during DNA replication,what will be joined to it?

Accepted Answer

A)  Any purine 
B)  One specific purine 
C)  One specific pyrimidine 
D)  Any pyramidine 
E)  A phosphate group 
A)  Any purine 
B)  One specific purine 
C)  One specific pyrimidine 
D)  Any pyramidine 
E)  A phosphate group

Exam 3: Nucleic Acids, Proteins, and Enzymes

Enzymes of the acid-base catalysis type contain

A nucleotide in DNA is made up of

The molecules that are acted on by an enzyme are called

All of the following contribute to the overall structure of proteins except

Leucine and valine have side chains consisting entirely of C and H;therefore,the side chains

The inhibition of enzyme activity by noncompetitive inhibitors can be reduced

The rate of a chemical reaction in a cell is the measure of how

The maximum possible rate of an enzyme reaction that is influenced by a competitive inhibitor depends on the concentration of

Which solution is least likely to denature an enzyme?

The active site of an enzyme

The sides of the "ladder" that makes up a nucleic acid molecule are made of

Aspartate and glutamate have side chains terminating in carboxyl groups;therefore,they

Which statement about DNA and RNA is true?

The addition of the competitive inhibitor mevinolin slows the reaction HMG-CoA →\rightarrow→ mevalonate,which is catalyzed by the enzyme HMG-CoA reductase.The effects of mevinolin would be overcome and the rate of the reaction increased by

The amino acid lysine

The binding of substrate to enzyme creates a(n)

All of the following will increase the rate of conversion of reactant A to product B in the presence of enzyme C except

The quaternary structure of a protein

When organisms are adapted to movement between different environments,they sometimes synthesize variations of existing enzymes,which are called

If there is an exposed purine during DNA replication,what will be joined to it?

Introduction

The Chemistry and Energy of Life

Cells: the Working Units of Life

Cell Membranes and Signaling

Pathways That Harvest and Store Chemical Energy

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

DNA and Its Role in Heredity

From Dna to Protein: Gene Expression

Regulation of Gene Expression

Genomes

Biotechnology

Genes, Development, and Evolution

Processes of Evolution

Reconstructing and Using Phylogenies

Speciation

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

The Evolution of Plants

The Evolution and Diversity of Fungi

Animal Origins and Diversity

The Plant Body

Plant Nutrition and Transport

Plant Growth and Development

Reproduction of Flowering Plants

Plants in the Environment

Fundamentals of Animal Function

Nutrition and Digestion

Breathing

Circulation

Muscle and Movement

Neurons, Sense Organs, and Nervous Systems

Nervous and Endocrine Control

Water and Salts: Excretion

Animal Reproduction

Animal Development

Immunology: Animal Defense Systems

Animal Behavior

The Distribution of Earths Ecological Systems

Populations

Ecological and Evolutionary Consequences of Interactions Within and Among Species

Ecological Communities

The Global Ecosystem

Filters

The addition of the competitive inhibitor mevinolin slows the reaction HMG-CoA $\rightarrow$ mevalonate,which is catalyzed by the enzyme HMG-CoA reductase.The effects of mevinolin would be overcome and the rate of the reaction increased by