Question 1

An allosteric inhibitor

Accepted Answer

A)  decreases the concentration of an inactive enzyme. 
B)  changes the shape of an enzyme. 
C)  increases the concentration of a product. 
D)  changes the shape of a substrate. 
E)  increases the concentration of an enzyme-substrate complex. 
A)  decreases the concentration of an inactive enzyme. 
B)  changes the shape of an enzyme. 
C)  increases the concentration of a product. 
D)  changes the shape of a substrate. 
E)  increases the concentration of an enzyme-substrate complex.

Question 2

The ability of an enzyme to change shape when it binds to its substrate is called

Accepted Answer

A)  induced fit. 
B)  enzyme flex. 
C)  the lock-and-key paradox. 
D)  substrate-induced active site shaping. 
E)  enzyme retrofit. 
A)  induced fit. 
B)  enzyme flex. 
C)  the lock-and-key paradox. 
D)  substrate-induced active site shaping. 
E)  enzyme retrofit.

Question 3

The nucleotide sequence of DNA

Accepted Answer

A)  is the same in all organisms of a species. 
B)  contains only information for translation. 
C)  evolved before RNA. 
D)  contains the four bases A,T,G,and C. 
E)  All of the above 
A)  is the same in all organisms of a species. 
B)  contains only information for translation. 
C)  evolved before RNA. 
D)  contains the four bases A,T,G,and C. 
E)  All of the above

Question 4

A noncompetitive inhibitor may inhibit binding of a substrate to an enzyme by

Accepted Answer

A)  binding to the substrate. 
B)  binding to the active site. 
C)  lowering the activation energy. 
D)  increasing the$\Delta$G of the reaction. 
E)  changing the shape of the active site. 
A)  binding to the substrate. 
B)  binding to the active site. 
C)  lowering the activation energy. 
D)  increasing the$\Delta$G of the reaction. 
E)  changing the shape of the active site.

Question 5

Which statement about enzymes is false?

Accepted Answer

A)  All biochemical reactions require enzymes. 
B)  Enzymes lower activation energy. 
C)  Enzymes are highly specific. 
D)  Enzymes can convert an endergonic to an exergonic reaction. 
E)  Enzymes can be recycled. 
A)  All biochemical reactions require enzymes. 
B)  Enzymes lower activation energy. 
C)  Enzymes are highly specific. 
D)  Enzymes can convert an endergonic to an exergonic reaction. 
E)  Enzymes can be recycled.

Question 6

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 7

Which type of inhibitor can be overcome by the addition of more substrate?

Accepted Answer

A)  Irreversible 
B)  Noncompetitive 
C)  Competitive 
D)  Prosthetic 
E)  Isotonic 
A)  Irreversible 
B)  Noncompetitive 
C)  Competitive 
D)  Prosthetic 
E)  Isotonic

Question 8

Allosteric inhibitors can act by

Accepted Answer

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

Question 9

DNA carries genetic information in its

Accepted Answer

A)  helical form. 
B)  sequence of bases. 
C)  tertiary sequence. 
D)  sequence of amino acids. 
E)  phosphate groups. 
A)  helical form. 
B)  sequence of bases. 
C)  tertiary sequence. 
D)  sequence of amino acids. 
E)  phosphate groups.

Question 10

Which factor determines the rate of a reaction?

Accepted Answer

A)  Entropy 
B)  $\Delta$ G 
C)  The laws of thermodynamics 
D)  The activation energy 
E)  The overall change in free energy 
A)  Entropy 
B)  $\Delta$ G 
C)  The laws of thermodynamics 
D)  The activation energy 
E)  The overall change in free energy

Question 11

Which statement about the differences between DNA and RNA is false?

Accepted Answer

A)  DNA has thymine,whereas RNA has uracil. 
B)  DNA usually has two polynucleotide strands,whereas RNA usually has one strand. 
C)  DNA has deoxyribose sugar,whereas RNA has ribose sugar. 
D)  DNA is a polymer,whereas RNA is a monomer. 
E)  In DNA,A pairs with T,whereas in RNA,A pairs with U. 
A)  DNA has thymine,whereas RNA has uracil. 
B)  DNA usually has two polynucleotide strands,whereas RNA usually has one strand. 
C)  DNA has deoxyribose sugar,whereas RNA has ribose sugar. 
D)  DNA is a polymer,whereas RNA is a monomer. 
E)  In DNA,A pairs with T,whereas in RNA,A pairs with U.

Question 12

Amino acids can be grouped according to the properties of their

Accepted Answer

A)  amino groups. 
B)  hydrogen. 
C)  carboxyl groups. 
D)  R groups. 
E)  $\alpha$ carbon. 
A)  amino groups. 
B)  hydrogen. 
C)  carboxyl groups. 
D)  R groups. 
E)  $\alpha$ carbon.

Question 13

According to the principle of complementary base pairing,purines always pair with

Accepted Answer

A)  deoxyribose sugars. 
B)  uracil. 
C)  pyrimidines. 
D)  adenine. 
E)  guanine. 
A)  deoxyribose sugars. 
B)  uracil. 
C)  pyrimidines. 
D)  adenine. 
E)  guanine.

Question 14

In DNA,A pairs with T,and C pairs with G;these are examples of a specific type of reaction called

Accepted Answer

A)  complementary base pairing. 
B)  a dehydration reaction. 
C)  a reduction reaction. 
D)  a hydrophobic reaction. 
E)  a purine-purine reaction. 
A)  complementary base pairing. 
B)  a dehydration reaction. 
C)  a reduction reaction. 
D)  a hydrophobic reaction. 
E)  a purine-purine reaction.

Question 15

Enzymatic reactions can become saturated as substrate concentration increases because

Accepted Answer

A)  enzymes have the maximum possible number of hydrogen atoms attached to them. 
B)  the concentration of substrate reaches a point at which it cannot increase any further. 
C)  substrates are inhibitors of enzymes. 
D)  the activation energy of the reaction reaches a point at which it cannot be lowered further. 
E)  there are a limited number of the enzyme molecules present. 
A)  enzymes have the maximum possible number of hydrogen atoms attached to them. 
B)  the concentration of substrate reaches a point at which it cannot increase any further. 
C)  substrates are inhibitors of enzymes. 
D)  the activation energy of the reaction reaches a point at which it cannot be lowered further. 
E)  there are a limited number of the enzyme molecules present.

Question 16

Peptide chains have a(n)_______ and a(n)_______.

Accepted Answer

A)  start end;stop end 
B)  positive end;negative end 
C)  N terminus;C terminus 
D)  5ʹ end;3ʹ end 
E)  A end;Z end 
A)  start end;stop end 
B)  positive end;negative end 
C)  N terminus;C terminus 
D)  5ʹ end;3ʹ end 
E)  A end;Z end

Question 17

The amino acids of the protein keratin are arranged in an $\alpha$ helix.This secondary structure is stabilized by

Accepted Answer

A)  covalent bonds. 
B)  peptide bonds. 
C)  glycosidic linkages. 
D)  polar bonds. 
E)  hydrogen bonds. 
A)  covalent bonds. 
B)  peptide bonds. 
C)  glycosidic linkages. 
D)  polar bonds. 
E)  hydrogen bonds.

Question 18

The insecticide malathion acts by

Accepted Answer

A)  bonding covalently with a lipid. 
B)  acting as a competitive inhibitor. 
C)  reacting with sugars. 
D)  blocking binding of ATP to enzymes. 
E)  bonding covalently to the active site of the enzyme acetylcholinesterase. 
A)  bonding covalently with a lipid. 
B)  acting as a competitive inhibitor. 
C)  reacting with sugars. 
D)  blocking binding of ATP to enzymes. 
E)  bonding covalently to the active site of the enzyme acetylcholinesterase.

Question 19

Which statement about the primary structure of a protein is false?

Accepted Answer

A)  It may be branched. 
B)  It is held together by covalent bonds. 
C)  It is unique to that protein. 
D)  It determines the tertiary structure of the protein. 
E)  It is the sequence of amino acids in the protein. 
A)  It may be branched. 
B)  It is held together by covalent bonds. 
C)  It is unique to that protein. 
D)  It determines the tertiary structure of the protein. 
E)  It is the sequence of amino acids in the protein.

Question 20

If pyrimidines could bind to other pyrimidines,and purines could bind to other purines,what would be the impact on the DNA double helix?

Accepted Answer

A)  The width of the double helix would vary rather than having a fixed width. 
B)  The phosphodiester bonds would be unable to form. 
C)  There would be a reduced requirement for phosphates in nucleotides. 
D)  The DNA backbone would be made of nucleosides. 
E)  The sugar would need to be ribose instead of deoxyribose. 
A)  The width of the double helix would vary rather than having a fixed width. 
B)  The phosphodiester bonds would be unable to form. 
C)  There would be a reduced requirement for phosphates in nucleotides. 
D)  The DNA backbone would be made of nucleosides. 
E)  The sugar would need to be ribose instead of deoxyribose.

Exam 3: Nucleic Acids, Proteins, and Enzymes

An allosteric inhibitor

The ability of an enzyme to change shape when it binds to its substrate is called

The nucleotide sequence of DNA

A noncompetitive inhibitor may inhibit binding of a substrate to an enzyme by

Which statement about enzymes is false?

Competitive inhibitors of enzymes work by

Which type of inhibitor can be overcome by the addition of more substrate?

Allosteric inhibitors can act by

DNA carries genetic information in its

Which factor determines the rate of a reaction?

Which statement about the differences between DNA and RNA is false?

Amino acids can be grouped according to the properties of their

According to the principle of complementary base pairing,purines always pair with

In DNA,A pairs with T,and C pairs with G;these are examples of a specific type of reaction called

Enzymatic reactions can become saturated as substrate concentration increases because

Peptide chains have a(n)_______ and a(n)_______.

The amino acids of the protein keratin are arranged in an α\alphaα helix.This secondary structure is stabilized by

The insecticide malathion acts by

Which statement about the primary structure of a protein is false?

If pyrimidines could bind to other pyrimidines,and purines could bind to other purines,what would be the impact on the DNA double helix?

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

Peptide chains have a(n)_ and a(n)_.

The amino acids of the protein keratin are arranged in an $\alpha$ helix.This secondary structure is stabilized by