Question 1

Knowing the change in free energy ($\Delta$G)of a reaction tells us

Accepted Answer

A)  the energy yield of the reaction. 
B)  the rate of the reaction. 
C)  the end concentration of products. 
D)  the optimum temperature for the reaction. 
E)  the activation energy. 
A)  the energy yield of the reaction. 
B)  the rate of the reaction. 
C)  the end concentration of products. 
D)  the optimum temperature for the reaction. 
E)  the activation energy.

Question 2

Trypsin and elastase are both enzymes that catalyze hydrolysis of peptide bonds.But trypsin only cuts next to lysine and elastase only cuts next to alanine.Why?

Accepted Answer

A)  Trypsin is a protein,and elastase is not. 
B)  $\Delta$ G for the two reactions is different. 
C)  The shape of the active site for the two enzymes is different. 
D)  One of the reactions is endergonic and the other is exergonic. 
E)  Hydrolysis of lysine bonds requires water,whereas hydrolysis of alanine bonds does not. 
A)  Trypsin is a protein,and elastase is not. 
B)  $\Delta$ G for the two reactions is different. 
C)  The shape of the active site for the two enzymes is different. 
D)  One of the reactions is endergonic and the other is exergonic. 
E)  Hydrolysis of lysine bonds requires water,whereas hydrolysis of alanine bonds does not.

Question 3

An active site is

Accepted Answer

A)  the part of the substrate that binds with an enzyme. 
B)  the part of the enzyme that binds with a substrate. 
C)  the site where energy is added to an enzyme catalyst. 
D)  the site where enzymes are found in cells. 
E)  important in determining secondary structure. 
A)  the part of the substrate that binds with an enzyme. 
B)  the part of the enzyme that binds with a substrate. 
C)  the site where energy is added to an enzyme catalyst. 
D)  the site where enzymes are found in cells. 
E)  important in determining secondary structure.

Question 4

Theoretically,the number of different proteins that can be made from 50 amino acids is

Accepted Answer

A)  5020. 
B)  20 × 50. 
C)  2050. 
D)  1050. 
E)  250. 
A)  5020. 
B)  20 × 50. 
C)  2050. 
D)  1050. 
E)  250.

Question 5

A(n)_______ protein is a protein that has become nonfunctional due to the loss of its three-dimensional structure.

Accepted Answer

A)  permanent 
B)  reversible 
C)  denatured 
D)  hydrolyzed 
E)  environmentalized 
A)  permanent 
B)  reversible 
C)  denatured 
D)  hydrolyzed 
E)  environmentalized

Question 6

Which statement about temperature effects is false?

Accepted Answer

A)  Raising the temperature may reduce the activity of an enzyme. 
B)  Raising the temperature may increase the activity of an enzyme. 
C)  Raising the temperature may denature an enzyme. 
D)  Some enzymes are stable at the boiling point of water. 
E)  All enzymes have the same optimal temperature. 
A)  Raising the temperature may reduce the activity of an enzyme. 
B)  Raising the temperature may increase the activity of an enzyme. 
C)  Raising the temperature may denature an enzyme. 
D)  Some enzymes are stable at the boiling point of water. 
E)  All enzymes have the same optimal temperature.

Question 7

Aspirin provides a classic example of the interplay between a natural remedy and modern science.By means of organic chemistry,the active ingredient of willow powder,_______,was chemically analyzed and then synthesized.

Accepted Answer

The answer of Aspirin provides a classic example of the...

Question 8

DNA molecules can differ from one another in their

Accepted Answer

A)  physical shape. 
B)  function. 
C)  base sequences. 
D)  hydrogen bonds. 
E)  complementary base pairing. 
A)  physical shape. 
B)  function. 
C)  base sequences. 
D)  hydrogen bonds. 
E)  complementary base pairing.

Question 9

Almost all enzymes are

Accepted Answer

A)  DNA. 
B)  lipids. 
C)  carbohydrates. 
D)  proteins. 
E)  amino acids. 
A)  DNA. 
B)  lipids. 
C)  carbohydrates. 
D)  proteins. 
E)  amino acids.

Question 10

You have duplicated the threonine to isoleucine metabolic pathway and want to determine the saturation level of threonine.You slowly add increasing amounts of threonine and observe that the reaction rate initially increases slowly and then decreases.You also note that increasing the amount of isoleucine decreases the rate of the reaction.You determine that the pathway is thus regulated by

Accepted Answer

A)  feedback inhibition. 
B)  a noncompetitive inhibitor. 
C)  a competitive inhibitor. 
D)  a coenzyme. 
E)  a prosthetic. 
A)  feedback inhibition. 
B)  a noncompetitive inhibitor. 
C)  a competitive inhibitor. 
D)  a coenzyme. 
E)  a prosthetic.

Question 11

When an egg is exposed to extreme heat it turns from a liquid substance into a solid substance.Even when the egg is allowed to cool,these changes are not reversible for a number of reasons.Which is not one of those reasons?

Accepted Answer

A)  Water has been removed from the egg proteins. 
B)  Rapidly moving molecules have broken apart hydrogen bonds and hydrophobic interactions in the egg's proteins. 
C)  Proteins in the egg have become denatured and lost secondary and tertiary structure. 
D)  The denatured proteins have aggregated. 
E)  Fats in the egg have become saturated and less fluid. 
A)  Water has been removed from the egg proteins. 
B)  Rapidly moving molecules have broken apart hydrogen bonds and hydrophobic interactions in the egg's proteins. 
C)  Proteins in the egg have become denatured and lost secondary and tertiary structure. 
D)  The denatured proteins have aggregated. 
E)  Fats in the egg have become saturated and less fluid.

Question 12

Which of the following is an enzyme?

Accepted Answer

A)  Copper 
B)  Heme 
C)  Catalase 
D)  Hydrogen peroxide 
E)  Retinal 
A)  Copper 
B)  Heme 
C)  Catalase 
D)  Hydrogen peroxide 
E)  Retinal

Question 13

Which amino acid is small enough to fit into the tight corners of a protein molecule?

Accepted Answer

A)  Proline 
B)  Glycine 
C)  Cysteine 
D)  Asparagine 
E)  Glutamine 
A)  Proline 
B)  Glycine 
C)  Cysteine 
D)  Asparagine 
E)  Glutamine

Question 14

Which amino acid has a sulfur atom?

Accepted Answer

A)  Proline 
B)  Arginine 
C)  Methionine 
D)  Alanine 
E)  Glutamine 
A)  Proline 
B)  Arginine 
C)  Methionine 
D)  Alanine 
E)  Glutamine

Question 15

Which interaction does not determine tertiary structure?

Accepted Answer

A)  Hydrogen bond 
B)  Disulfide bridge 
C)  Glycosidic linkage 
D)  van der Waals interaction 
E)  Ionic bond 
A)  Hydrogen bond 
B)  Disulfide bridge 
C)  Glycosidic linkage 
D)  van der Waals interaction 
E)  Ionic bond

Question 16

A reactant reaches the transition state

Accepted Answer

A)  right before the energy barrier is overcome. 
B)  when it is ready to receive energy. 
C)  after releasing free energy. 
D)  when there is an input of energy to initiate the reaction. 
E)  only when enzymes are used. 
A)  right before the energy barrier is overcome. 
B)  when it is ready to receive energy. 
C)  after releasing free energy. 
D)  when there is an input of energy to initiate the reaction. 
E)  only when enzymes are used.

Question 17

Which of the following depend(s)on complementary base pairing?

Accepted Answer

A)  DNA replication 
B)  Transcription 
C)  Translation 
D)  Folding of an RNA molecule back on itself 
E)  All of the above 
A)  DNA replication 
B)  Transcription 
C)  Translation 
D)  Folding of an RNA molecule back on itself 
E)  All of the above

Question 18

A nucleotide consists of a pentose sugar,a phosphate group,and a(n)

Accepted Answer

A)  lipid. 
B)  acid. 
C)  nitrogen-containing base. 
D)  amino acid. 
E)  glycerol. 
A)  lipid. 
B)  acid. 
C)  nitrogen-containing base. 
D)  amino acid. 
E)  glycerol.

Question 19

The statement "enzymes are highly specific" means that certain

Accepted Answer

A)  enzymes are found in certain cells. 
B)  reactions involving certain substrates are catalyzed by specific enzymes. 
C)  enzymes require certain concentrations of substrates. 
D)  enzymes are matched to reactions based on the activation energy level. 
E)  concentrations of substrates work with certain enzymes. 
A)  enzymes are found in certain cells. 
B)  reactions involving certain substrates are catalyzed by specific enzymes. 
C)  enzymes require certain concentrations of substrates. 
D)  enzymes are matched to reactions based on the activation energy level. 
E)  concentrations of substrates work with certain enzymes.

Question 20

The tertiary structure of a protein is determined by its

Accepted Answer

A)  interactions among R groups. 
B)  right-handed coil. 
C)  hydrogen bonding. 
D)  branching. 
E)  glycosidic linkages. 
A)  interactions among R groups. 
B)  right-handed coil. 
C)  hydrogen bonding. 
D)  branching. 
E)  glycosidic linkages.

Exam 3: Nucleic Acids, Proteins, and Enzymes

Knowing the change in free energy ( Δ\DeltaΔ G)of a reaction tells us

Trypsin and elastase are both enzymes that catalyze hydrolysis of peptide bonds.But trypsin only cuts next to lysine and elastase only cuts next to alanine.Why?

An active site is

Theoretically,the number of different proteins that can be made from 50 amino acids is

A(n)_______ protein is a protein that has become nonfunctional due to the loss of its three-dimensional structure.

Which statement about temperature effects is false?

Aspirin provides a classic example of the interplay between a natural remedy and modern science.By means of organic chemistry,the active ingredient of willow powder,_______,was chemically analyzed and then synthesized.

DNA molecules can differ from one another in their

Almost all enzymes are

When an egg is exposed to extreme heat it turns from a liquid substance into a solid substance.Even when the egg is allowed to cool,these changes are not reversible for a number of reasons.Which is not one of those reasons?

Which of the following is an enzyme?

Which amino acid is small enough to fit into the tight corners of a protein molecule?

Which amino acid has a sulfur atom?

Which interaction does not determine tertiary structure?

A reactant reaches the transition state

Which of the following depend(s)on complementary base pairing?

A nucleotide consists of a pentose sugar,a phosphate group,and a(n)

The statement "enzymes are highly specific" means that certain

The tertiary structure of a protein is determined by its

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

Knowing the change in free energy ( $\Delta$ G)of a reaction tells us