Question 1

Explain the term feedback as a mechanism for control of biochemical reactions.

Accepted Answer

Feedback control means that the product

Question 2

The mechanism of enzyme control that is similar to noncompetitive inhibition because both involve interactions with the enzyme at locations other than the active site is

Accepted Answer

A) feedback inhibition. 
B) zymogen production. 
C) zymogen activation. 
D) allosteric interaction. 
E) genetic control. 
A) feedback inhibition. 
B) zymogen production. 
C) zymogen activation. 
D) allosteric interaction. 
E) genetic control.

Question 3

Antioxidants contribute to good health by reacting with

Accepted Answer

A) coenzymes. 
B) vitamins. 
C) hormones. 
D) free radicals. 
E) hydrogen ions. 
A) coenzymes. 
B) vitamins. 
C) hormones. 
D) free radicals. 
E) hydrogen ions.

Question 4

An enzyme that catalyzes the conversion of a cis double bond to a trans double bond is classified as a(an)

Accepted Answer

A) ligase. 
B) isomerase. 
C) oxidoreductase. 
D) transferase. 
E) hydrolase. 
A) ligase. 
B) isomerase. 
C) oxidoreductase. 
D) transferase. 
E) hydrolase.

Question 5

Match the following.
-induced-fit model

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 6

When a molecule other than the correct substrate interacts with some part of an enzyme to alter the shape of the active site,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 7

A compound that is necessary for the synthesis of another compound is called a(an)

Accepted Answer

A) allosteric inhibitor. 
B) cofactor. 
C) precursor. 
D) proenzyme. 
E) zymogen. 
A) allosteric inhibitor. 
B) cofactor. 
C) precursor. 
D) proenzyme. 
E) zymogen.

Question 8

Match the following.
-ligase

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 9

Which of the following fat-soluble vitamins is associated with good night vision?

Accepted Answer

A) Vitamin A 
B) Vitamin D 
C) Vitamin E 
D) Vitamin K 
E) More than one answer is possible. 
A) Vitamin A 
B) Vitamin D 
C) Vitamin E 
D) Vitamin K 
E) More than one answer is possible.

Question 10

Which of the following is the typical shape of a plot showing the rate of an enzyme-catalyzed reaction as a function of the enzyme concentration with excess substrate?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
A) 
  
B) 
  
C) 
  
D)

Question 11

Match the following.
-lock-and-key model

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 12

The following reaction would most likely be catalyzed by an enzyme of which class?
Sucrose + H2O → glucose + fructose

Accepted Answer

A) synthetase or ligase 
B) oxidoreductase 
C) hydrolase 
D) transferase 
E) isomerase 
A) synthetase or ligase 
B) oxidoreductase 
C) hydrolase 
D) transferase 
E) isomerase

Question 13

Transaminase can be classified as a(an)________ because its function is moving an amine group from one molecule to another.

Accepted Answer

A) ligase 
B) isomerase 
C) oxidoreductase 
D) transferase 
E) hydrolase 
A) ligase 
B) isomerase 
C) oxidoreductase 
D) transferase 
E) hydrolase

Question 14

Overdosing on vitamins A and D is more likely than overdosing on vitamin C because

Accepted Answer

A) vitamins A and D are fat soluble and thus can accumulate in body fat,where vitamin C is water soluble and the excess will be excreted in urine. 
B) vitamin C is fat soluble and thus can accumulate in body fat,where vitamins A and D are water soluble and the excess will be excreted in urine. 
C) vitamin C is biologically active as consumed in foods,but vitamins A and D must be converted into biologically active forms before utilization. 
D) vitamins A and D are biologically active as consumed in foods,but vitamin C must be converted into biologically active forms before utilization. 
E) vitamins A and D are needed in much larger doses than vitamin C. 
A) vitamins A and D are fat soluble and thus can accumulate in body fat,where vitamin C is water soluble and the excess will be excreted in urine. 
B) vitamin C is fat soluble and thus can accumulate in body fat,where vitamins A and D are water soluble and the excess will be excreted in urine. 
C) vitamin C is biologically active as consumed in foods,but vitamins A and D must be converted into biologically active forms before utilization. 
D) vitamins A and D are biologically active as consumed in foods,but vitamin C must be converted into biologically active forms before utilization. 
E) vitamins A and D are needed in much larger doses than vitamin C.

Question 15

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

Accepted Answer

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

Question 16

Which of the following combinations is required to create a holoenzyme?

Accepted Answer

A) effector + coenzyme 
B) apoenzyme + activator 
C) apoenzyme + coenzyme 
D) None of the above are correct combinations. 
A) effector + coenzyme 
B) apoenzyme + activator 
C) apoenzyme + coenzyme 
D) None of the above are correct combinations.

Question 17

Which term identifies the relatively small portion of the enzyme that is directly involved in the biochemical reaction being catalyzed?

Accepted Answer

A) substrate 
B) active site 
C) N-terminal 
D) C-terminal 
E) precursor 
A) substrate 
B) active site 
C) N-terminal 
D) C-terminal 
E) precursor

Question 18

Match the following.
-antioxidant

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 19

Match the following.
-hydrolase

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 20

Which factor is not important in explaining how enzymes work?

Accepted Answer

A) Two different substrate molecules are brought into close contact. 
B) Substrates are brought into solution more easily. 
C) The bonds in substrates are subjected to strains which weaken them. 
D) Substrates are forced into the correct orientation for interaction. 
E) Substrates are placed near acidic or basic sites. 
A) Two different substrate molecules are brought into close contact. 
B) Substrates are brought into solution more easily. 
C) The bonds in substrates are subjected to strains which weaken them. 
D) Substrates are forced into the correct orientation for interaction. 
E) Substrates are placed near acidic or basic sites.

Exam 19: Enzymes and Vitamins

Explain the term feedback as a mechanism for control of biochemical reactions.

The mechanism of enzyme control that is similar to noncompetitive inhibition because both involve interactions with the enzyme at locations other than the active site is

Antioxidants contribute to good health by reacting with

An enzyme that catalyzes the conversion of a cis double bond to a trans double bond is classified as a(an)

Match the following. -induced-fit model

When a molecule other than the correct substrate interacts with some part of an enzyme to alter the shape of the active site,the process is called

A compound that is necessary for the synthesis of another compound is called a(an)

Match the following. -ligase

Which of the following fat-soluble vitamins is associated with good night vision?

Which of the following is the typical shape of a plot showing the rate of an enzyme-catalyzed reaction as a function of the enzyme concentration with excess substrate?

Match the following. -lock-and-key model

The following reaction would most likely be catalyzed by an enzyme of which class? Sucrose + H2O → glucose + fructose

Transaminase can be classified as a(an)________ because its function is moving an amine group from one molecule to another.

Overdosing on vitamins A and D is more likely than overdosing on vitamin C because

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

Which of the following combinations is required to create a holoenzyme?

Which term identifies the relatively small portion of the enzyme that is directly involved in the biochemical reaction being catalyzed?

Match the following. -antioxidant

Match the following. -hydrolase

Which factor is not important in explaining how enzymes work?

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

Body Fluids

Filters

The following reaction would most likely be catalyzed by an enzyme of which class? Sucrose + H₂O → glucose + fructose