Question 1

Substances the bind to an enzyme and increase its activity are called

Accepted Answer

A) negative regulators. 
B) positive regulators. 
C) allosteric regulators. 
D) neutral regulators. 
A) negative regulators. 
B) positive regulators. 
C) allosteric regulators. 
D) neutral regulators.

Question 2

When a metal ion such as Pb(II)interferes with the functioning of an enzyme,the most probable mechanism is

Accepted Answer

A) feedback control. 
B) reversible noncompetitive inhibition. 
C) genetic control. 
D) reversible competitive inhibition. 
E) irreversible inhibition. 
A) feedback control. 
B) reversible noncompetitive inhibition. 
C) genetic control. 
D) reversible competitive inhibition. 
E) irreversible inhibition.

Question 3

Which aspect of enzyme structure is related to our dietary need for trace minerals?

Accepted Answer

A) cofactor 
B) active site 
C) turnover number 
D) chirality 
E) none of these 
A) cofactor 
B) active site 
C) turnover number 
D) chirality 
E) none of these

Question 4

When there is an increase in temperature it can affect an enzyme-catalyzed reaction by

Accepted Answer

A) increasing the reaction rate 
B) decreasing the reaction rate 
C) both increasing and decreasing the reaction rate 
D) causing a different substrate to be used 
A) increasing the reaction rate 
B) decreasing the reaction rate 
C) both increasing and decreasing the reaction rate 
D) causing a different substrate to be used

Question 5

Enzymes that are affected by the binding of an activator are called

Accepted Answer

A) zymogens. 
B) proenzymes. 
C) allosteric enzymes. 
D) induced enzymes. 
A) zymogens. 
B) proenzymes. 
C) allosteric enzymes. 
D) induced enzymes.

Question 6

The tertiary structure of most enzymes is

Accepted Answer

A) an α-helix. 
B) a β-pleated sheet. 
C) fibrous. 
D) globular. 
E) none of these. 
A) an α-helix. 
B) a β-pleated sheet. 
C) fibrous. 
D) globular. 
E) none of these.

Question 7

Some enzymes are produced as zymogens because

Accepted Answer

A) the reactions they catalyze are undesirable at the site of production. 
B) they must have both an active site and an allosteric site,and these can't be produced simultaneously. 
C) the actual enzyme molecules are so large that they must be produced in pieces and assembled as needed. 
D) the pH at the site of production is very different from the pH at the site where they are used. 
E) none of these 
A) the reactions they catalyze are undesirable at the site of production. 
B) they must have both an active site and an allosteric site,and these can't be produced simultaneously. 
C) the actual enzyme molecules are so large that they must be produced in pieces and assembled as needed. 
D) the pH at the site of production is very different from the pH at the site where they are used. 
E) none of these

Question 8

When an enzyme is saturated it

Accepted Answer

A) has been completely consumed,and that reaction cannot occur again until new enzymes are produced. 
B) is in high concentration relative to the substrate,and the reaction rate is directly proportional to substrate concentration. 
C) is in low concentration relative to the substrate,and the reaction rate is directly proportional to enzyme concentration. 
D) is in low concentration relative to the substrate,and the reaction rate approaches its maximum. 
E) none of the above 
A) has been completely consumed,and that reaction cannot occur again until new enzymes are produced. 
B) is in high concentration relative to the substrate,and the reaction rate is directly proportional to substrate concentration. 
C) is in low concentration relative to the substrate,and the reaction rate is directly proportional to enzyme concentration. 
D) is in low concentration relative to the substrate,and the reaction rate approaches its maximum. 
E) none of the above

Question 9

If a covalent bond forms between an enzyme and an inhibitor the reaction catalyzed by this enzyme will have undergone ________.

Accepted Answer

A) irreversible inhibition 
B) competitive inhibition 
C) noncompetitive inhibition 
D) feedback control 
E) genetic control 
A) irreversible inhibition 
B) competitive inhibition 
C) noncompetitive inhibition 
D) feedback control 
E) genetic control

Question 10

Match the following.
-vitamin

Accepted Answer

A) a description of the catalytic activity of an enzyme,where a small value means that very few molecules are acted on in a unit of time 
B) a substance that prevents harmful reactions of free radicals 
C) any process that increases the rate of an enzyme catalyzed reaction 
D) a type of enzyme that catalyzes the removal of a small molecule from a larger one 
E) a type of enzyme that catalyzes the internal rearrangement of molecules
F)an inactive form of an enzyme; also called a proenzyme
G)a description of enzyme activity based on an exact match between the shapes of the active site and the substrate molecule
H)a type of enzyme that catalyzes the joining of two molecules together
I)a type of enzyme that catalyzes the transfer of a functional group from one molecule to another
J)a type of enzyme that catalyzes the breakdown of large molecules by reaction with water
K)a description of enzyme activity based on the ability of the enzyme to change shape in order to accommodate substrate molecules
L)a type of enzyme that catalyzes oxidation or reduction reactions
M)a small organic molecule necessary for good health that must be obtained in the diet
N)any process which decreases the rate of an enzyme catalyzed reaction 
A) a description of the catalytic activity of an enzyme,where a small value means that very few molecules are acted on in a unit of time 
B) a substance that prevents harmful reactions of free radicals 
C) any process that increases the rate of an enzyme catalyzed reaction 
D) a type of enzyme that catalyzes the removal of a small molecule from a larger one 
E) a type of enzyme that catalyzes the internal rearrangement of molecules
F)an inactive form of an enzyme; also called a proenzyme
G)a description of enzyme activity based on an exact match between the shapes of the active site and the substrate molecule
H)a type of enzyme that catalyzes the joining of two molecules together
I)a type of enzyme that catalyzes the transfer of a functional group from one molecule to another
J)a type of enzyme that catalyzes the breakdown of large molecules by reaction with water
K)a description of enzyme activity based on the ability of the enzyme to change shape in order to accommodate substrate molecules
L)a type of enzyme that catalyzes oxidation or reduction reactions
M)a small organic molecule necessary for good health that must be obtained in the diet
N)any process which decreases the rate of an enzyme catalyzed reaction

Question 11

Which of the following does not generally increase the rate of a reaction?

Accepted Answer

A) increasing the reactants 
B) increasing the products 
C) increasing the temperature 
D) adding the catalyst 
A) increasing the reactants 
B) increasing the products 
C) increasing the temperature 
D) adding the catalyst

Question 12

When a molecule similar to the correct substrate interacts with the active site of an enzyme,the process is called

Accepted Answer

A) competitive inhibition. 
B) noncompetitive inhibition. 
C) irreversible inhibition. 
D) activation. 
E) covalent modification. 
A) competitive inhibition. 
B) noncompetitive inhibition. 
C) irreversible inhibition. 
D) activation. 
E) covalent modification.

Question 13

Enzymes function as catalysts by

Accepted Answer

A) changing the value of the free energy change to a more favorable value. 
B) changing the value of the equilibrium constant to a more favorable value. 
C) lowering the value of the activation energy. 
D) increasing the amount of time needed to reach equilibrium. 
E) becoming one of the reactants. 
A) changing the value of the free energy change to a more favorable value. 
B) changing the value of the equilibrium constant to a more favorable value. 
C) lowering the value of the activation energy. 
D) increasing the amount of time needed to reach equilibrium. 
E) becoming one of the reactants.

Question 14

Match the following.
-oxidoreductase

Accepted Answer

A) a description of the catalytic activity of an enzyme,where a small value means that very few molecules are acted on in a unit of time 
B) a substance that prevents harmful reactions of free radicals 
C) any process that increases the rate of an enzyme catalyzed reaction 
D) a type of enzyme that catalyzes the removal of a small molecule from a larger one 
E) a type of enzyme that catalyzes the internal rearrangement of molecules
F)an inactive form of an enzyme; also called a proenzyme
G)a description of enzyme activity based on an exact match between the shapes of the active site and the substrate molecule
H)a type of enzyme that catalyzes the joining of two molecules together
I)a type of enzyme that catalyzes the transfer of a functional group from one molecule to another
J)a type of enzyme that catalyzes the breakdown of large molecules by reaction with water
K)a description of enzyme activity based on the ability of the enzyme to change shape in order to accommodate substrate molecules
L)a type of enzyme that catalyzes oxidation or reduction reactions
M)a small organic molecule necessary for good health that must be obtained in the diet
N)any process which decreases the rate of an enzyme catalyzed reaction 
A) a description of the catalytic activity of an enzyme,where a small value means that very few molecules are acted on in a unit of time 
B) a substance that prevents harmful reactions of free radicals 
C) any process that increases the rate of an enzyme catalyzed reaction 
D) a type of enzyme that catalyzes the removal of a small molecule from a larger one 
E) a type of enzyme that catalyzes the internal rearrangement of molecules
F)an inactive form of an enzyme; also called a proenzyme
G)a description of enzyme activity based on an exact match between the shapes of the active site and the substrate molecule
H)a type of enzyme that catalyzes the joining of two molecules together
I)a type of enzyme that catalyzes the transfer of a functional group from one molecule to another
J)a type of enzyme that catalyzes the breakdown of large molecules by reaction with water
K)a description of enzyme activity based on the ability of the enzyme to change shape in order to accommodate substrate molecules
L)a type of enzyme that catalyzes oxidation or reduction reactions
M)a small organic molecule necessary for good health that must be obtained in the diet
N)any process which decreases the rate of an enzyme catalyzed reaction

Question 15

The maximum number of substrate molecules that one enzyme molecule can act on in a given unit of time is the

Accepted Answer

A) turnover number. 
B) equilibrium constant. 
C) rate constant. 
D) reduction factor. 
E) catalytic multiplier. 
A) turnover number. 
B) equilibrium constant. 
C) rate constant. 
D) reduction factor. 
E) catalytic multiplier.

Question 16

All of the following statements concerning vitamins are true except

Accepted Answer

A) fat-soluble vitamins have a high proportion of polar carbonyl and hydroxyl groups. 
B) it is possible to overdose on fat-soluble vitamins because they accumulate in fatty tissues. 
C) it is difficult to overdose on water-soluble vitamins because excess amounts can be excreted in the urine. 
D) vitamins A,D,E,and K are fat-soluble. 
E) vitamin C and the B vitamins are water-soluble. 
A) fat-soluble vitamins have a high proportion of polar carbonyl and hydroxyl groups. 
B) it is possible to overdose on fat-soluble vitamins because they accumulate in fatty tissues. 
C) it is difficult to overdose on water-soluble vitamins because excess amounts can be excreted in the urine. 
D) vitamins A,D,E,and K are fat-soluble. 
E) vitamin C and the B vitamins are water-soluble.

Question 17

An enzyme that is classified as a hydrolase is involved in ________ reactions.

Accepted Answer

A) oxidation 
B) reduction 
C) isomerization 
D) polymerization 
E) hydrolysis 
A) oxidation 
B) reduction 
C) isomerization 
D) polymerization 
E) hydrolysis

Question 18

All of the following are B vitamins except

Accepted Answer

A) ascorbic acid. 
B) cobalamin. 
C) niacin. 
D) pantothenic acid. 
E) thiamine. 
A) ascorbic acid. 
B) cobalamin. 
C) niacin. 
D) pantothenic acid. 
E) thiamine.

Question 19

Explain the term specificity as it applies to enzyme activity.

Accepted Answer

Specificity describes the degree of rest

Question 20

Match the following.
-lyase

Accepted Answer

A) a description of the catalytic activity of an enzyme,where a small value means that very few molecules are acted on in a unit of time 
B) a substance that prevents harmful reactions of free radicals 
C) any process that increases the rate of an enzyme catalyzed reaction 
D) a type of enzyme that catalyzes the removal of a small molecule from a larger one 
E) a type of enzyme that catalyzes the internal rearrangement of molecules
F)an inactive form of an enzyme; also called a proenzyme
G)a description of enzyme activity based on an exact match between the shapes of the active site and the substrate molecule
H)a type of enzyme that catalyzes the joining of two molecules together
I)a type of enzyme that catalyzes the transfer of a functional group from one molecule to another
J)a type of enzyme that catalyzes the breakdown of large molecules by reaction with water
K)a description of enzyme activity based on the ability of the enzyme to change shape in order to accommodate substrate molecules
L)a type of enzyme that catalyzes oxidation or reduction reactions
M)a small organic molecule necessary for good health that must be obtained in the diet
N)any process which decreases the rate of an enzyme catalyzed reaction 
A) a description of the catalytic activity of an enzyme,where a small value means that very few molecules are acted on in a unit of time 
B) a substance that prevents harmful reactions of free radicals 
C) any process that increases the rate of an enzyme catalyzed reaction 
D) a type of enzyme that catalyzes the removal of a small molecule from a larger one 
E) a type of enzyme that catalyzes the internal rearrangement of molecules
F)an inactive form of an enzyme; also called a proenzyme
G)a description of enzyme activity based on an exact match between the shapes of the active site and the substrate molecule
H)a type of enzyme that catalyzes the joining of two molecules together
I)a type of enzyme that catalyzes the transfer of a functional group from one molecule to another
J)a type of enzyme that catalyzes the breakdown of large molecules by reaction with water
K)a description of enzyme activity based on the ability of the enzyme to change shape in order to accommodate substrate molecules
L)a type of enzyme that catalyzes oxidation or reduction reactions
M)a small organic molecule necessary for good health that must be obtained in the diet
N)any process which decreases the rate of an enzyme catalyzed reaction

Exam 19: Enzymes and Vitamins

Substances the bind to an enzyme and increase its activity are called

When a metal ion such as Pb(II)interferes with the functioning of an enzyme,the most probable mechanism is

Which aspect of enzyme structure is related to our dietary need for trace minerals?

When there is an increase in temperature it can affect an enzyme-catalyzed reaction by

Enzymes that are affected by the binding of an activator are called

The tertiary structure of most enzymes is

Some enzymes are produced as zymogens because

When an enzyme is saturated it

If a covalent bond forms between an enzyme and an inhibitor the reaction catalyzed by this enzyme will have undergone ________.

Match the following. -vitamin

Which of the following does not generally increase the rate of a reaction?

When a molecule similar to the correct substrate interacts with the active site of an enzyme,the process is called

Enzymes function as catalysts by

Match the following. -oxidoreductase

The maximum number of substrate molecules that one enzyme molecule can act on in a given unit of time is the

All of the following statements concerning vitamins are true except

An enzyme that is classified as a hydrolase is involved in ________ reactions.

All of the following are B vitamins except

Explain the term specificity as it applies to enzyme activity.

Match the following. -lyase

Matter and Measurements

Atoms and the Periodic Table

Ionic Compounds

Molecular Compounds

Classification and Balancing of Chemical Reactions

Chemical Reactions: Mole and Mass Relationships

Chemical Reactions: Energy, rates, and Equilibrium

Gases, liquids, and Solids

Solutions

Acids and Bases

Nuclear Chemistry

Introduction to Organic Chemistry: Alkanes

Alkenes, alkynes, and Aromatic Compounds

Some Compounds With Oxygen, sulfur, or a Halogen

Amines

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Amino Acids and Proteins

The Generation of Biochemical Energy

Carbohydrates

Carbohydrate Metabolism

Lipids

Lipid Metabolism

Nucleic Acids and Protein Synthesis

Genomics

Protein and Amino Acid Metabolism

Chemical Messengers: Hormones, neurotransmitters, and Drugs

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