Question 1

Activation of zymogens involves the chemical process of

Accepted Answer

A) hydrogen bonding. 
B) covalent modification. 
C) complete hydrolysis. 
D) denaturation. 
E) oxidation-reduction. 
A) hydrogen bonding. 
B) covalent modification. 
C) complete hydrolysis. 
D) denaturation. 
E) oxidation-reduction.

Question 2

How is the rate of an enzyme catalyzed reaction affected by increasing enzyme concentration?

Accepted Answer

A) The rate increases directly as the concentration of enzyme increases with excess substrate. 
B) The rate decreases directly as the concentration of enzyme increases. 
C) The rate initially increases as the concentration of enzyme increases,but then remains constant in spite of increasing amount of enzyme. 
D) The rate initially increases as the concentration of enzyme increases,but then decreases once the concentration of enzyme passes an optimum level. 
E) none of the above 
A) The rate increases directly as the concentration of enzyme increases with excess substrate. 
B) The rate decreases directly as the concentration of enzyme increases. 
C) The rate initially increases as the concentration of enzyme increases,but then remains constant in spite of increasing amount of enzyme. 
D) The rate initially increases as the concentration of enzyme increases,but then decreases once the concentration of enzyme passes an optimum level. 
E) none of the above

Question 3

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 4

What is the function of enzymes?

Accepted Answer

A) structure and support 
B) energy reserves 
C) biochemical catalysts 
D) communication between cells 
E) physical protection 
A) structure and support 
B) energy reserves 
C) biochemical catalysts 
D) communication between cells 
E) physical protection

Question 5

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 6

The name of an enzyme can often be recognized by the ending

Accepted Answer

A) -ase. 
B) -ate. 
C) -ic acid. 
D) -ene. 
E) -ose. 
A) -ase. 
B) -ate. 
C) -ic acid. 
D) -ene. 
E) -ose.

Question 7

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 8

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 9

A vitamin is a

Accepted Answer

A) nutrient involving trace metals that is necessary for good health. 
B) polypeptide used to manufacture enzymes. 
C) lipid complex which is an important part of all cells. 
D) small organic molecule obtained from the diet and necessary for good health. 
E) complex molecule of four interlocking hydrocarbon rings. 
A) nutrient involving trace metals that is necessary for good health. 
B) polypeptide used to manufacture enzymes. 
C) lipid complex which is an important part of all cells. 
D) small organic molecule obtained from the diet and necessary for good health. 
E) complex molecule of four interlocking hydrocarbon rings.

Question 10

Each of the following phrases correctly describes enzymes except

Accepted Answer

A) dissolve in water. 
B) have a globular shape. 
C) behave as substrates. 
D) contain an active site. 
E) act as catalysts. 
A) dissolve in water. 
B) have a globular shape. 
C) behave as substrates. 
D) contain an active site. 
E) act as catalysts.

Question 11

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 12

Enzymes work as catalyst because

Accepted Answer

A) of a proximity effect between substrate and catalytic site. 
B) of an orientation effect in which the substrates are in the correct arrangement to facilitate catalysis. 
C) of an energy effect in which the activation energy barrier is lowered. 
D) All of these are correct. 
E) None of these are correct. 
A) of a proximity effect between substrate and catalytic site. 
B) of an orientation effect in which the substrates are in the correct arrangement to facilitate catalysis. 
C) of an energy effect in which the activation energy barrier is lowered. 
D) All of these are correct. 
E) None of these are correct.

Question 13

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 14

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 15

Match the following.
-turnover number

Accepted Answer

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

Question 16

Enzymes are members of which class of biomolecules?

Accepted Answer

A) carbohydrates 
B) lipids 
C) nucleic acids 
D) proteins 
E) steroids 
A) carbohydrates 
B) lipids 
C) nucleic acids 
D) proteins 
E) steroids

Question 17

Match the following.
-transferase

Accepted Answer

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

Question 18

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 19

All of the following vitamins are fat soluble except

Accepted Answer

A) vitamin A. 
B) vitamin K. 
C) vitamin C. 
D) vitamin D. 
E) vitamin E. 
A) vitamin A. 
B) vitamin K. 
C) vitamin C. 
D) vitamin D. 
E) vitamin E.

Question 20

Which of the following is the typical shape of a plot showing the rate of an enzyme-catalyzed reaction as a function of the pH?

Accepted Answer

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

Exam 19: Enzymes and Vitamins

Activation of zymogens involves the chemical process of

How is the rate of an enzyme catalyzed reaction affected by increasing enzyme concentration?

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?

What is the function of enzymes?

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

The name of an enzyme can often be recognized by the ending

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

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

A vitamin is a

Each of the following phrases correctly describes enzymes except

All of the following are B vitamins except

Enzymes work as catalyst because

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

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

Match the following. -turnover number

Enzymes are members of which class of biomolecules?

Match the following. -transferase

Antioxidants contribute to good health by reacting with

All of the following vitamins are fat soluble except

Which of the following is the typical shape of a plot showing the rate of an enzyme-catalyzed reaction as a function of the pH?

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

Aldehydes and Ketones

Amines

Carboxylic Acids and Their Derivatives

Amino Acids and Proteins

Carbohydrates

The Generation of Biochemical Energy

Carbohydrate Metabolism

Lipids

Lipid Metabolism

Protein and Amino Acid Metabolism

Nucleic Acids and Protein Synthesis

Genomics

Chemical Messengers: Hormones, neurotransmitters, and Drugs

Body Fluids

Filters