Question 1

Heavy metal ions are believed to act as ____ inhibitors.

Accepted Answer

A) reversible 
B) irreversible 
C) competitive 
D) noncompetitive 
A) reversible 
B) irreversible 
C) competitive 
D) noncompetitive

Question 2

Which of the following enzyme types have proven especially useful in diagnostic medicine?

Accepted Answer

A) allosteric enzyme 
B) proenzymes 
C) isoenzymes 
D) induced enzymes 
A) allosteric enzyme 
B) proenzymes 
C) isoenzymes 
D) induced enzymes

Question 3

Enzymes have specific temperature and pH ranges within which they function best.

Accepted Answer

A) True 
 B)False

Question 4

The catalytically inactive form of an enzyme is called a(n)_____ .

Accepted Answer

A) cofactor 
B) proenzyme 
C) apoenzyme 
D) activator 
A) cofactor 
B) proenzyme 
C) apoenzyme 
D) activator

Question 5

An enzyme is known to catalyze the conversion of proteins to amino acids.Which of the following would be a correct designation for the enzyme?

Accepted Answer

A) transferase 
B) oxidoreductase 
C) hydrolase 
D) lyase 
A) transferase 
B) oxidoreductase 
C) hydrolase 
D) lyase

Question 6

What type of enzyme would catalyze the following reaction?

Accepted Answer

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

Question 7

An irreversible inhibitor usually forms a covalent bond with the enzyme.

Accepted Answer

A) True 
 B)False

Question 8

When enzyme activity is graphed versus the following,which graph is a straight line?

Accepted Answer

A) substrate concentration 
B) enzyme concentration 
C) pH 
D) temperature 
A) substrate concentration 
B) enzyme concentration 
C) pH 
D) temperature

Question 9

Insulin is initially produced as proinsulin,an inactive form that contains extra amino acid residues.Proinsulin must be an apoenzyme.

Accepted Answer

A) True 
 B)False

Question 10

While most enzymes increase the rate of a reaction by providing a new mechanism with a lower activation energy,there are several examples where they can also increase the activation energy and slow down or stop a reaction.

Accepted Answer

A) True 
 B)False

Question 11

What is the function of an inhibitor?

Accepted Answer

A) slow down the rate of reaction 
B) inhibit the effect of temperature and pH changes on enzyme activity 
C) inhibit substrate effects on other chemicals in the reaction environment 
D) slow down the interaction between the solvent and the substrate 
A) slow down the rate of reaction 
B) inhibit the effect of temperature and pH changes on enzyme activity 
C) inhibit substrate effects on other chemicals in the reaction environment 
D) slow down the interaction between the solvent and the substrate

Question 12

Many drugs act as competitive inhibitors.

Accepted Answer

A) True 
 B)False

Question 13

The general term which refers to the catalytic ability of an enzyme is

Accepted Answer

A) enzyme turnover. 
B) enzyme activity. 
C) catalytic turnover. 
D) catalytic speed. 
A) enzyme turnover. 
B) enzyme activity. 
C) catalytic turnover. 
D) catalytic speed.

Question 14

Consider the following figure.The step labeled A is known to reduce the activity of Enzyme 1.This would be described as what type of enzyme regulation?

Accepted Answer

A) end product inhibition 
B) feedback inhibition 
C) allosteric inhibition 
D) competitive inhibition 
A) end product inhibition 
B) feedback inhibition 
C) allosteric inhibition 
D) competitive inhibition

Question 15

Sulfa drugs prevent bacterial growth by acting as ____ inhibitors.

Accepted Answer

A) competitive 
B) noncompetitive 
C) irreversible 
D) more than one response is correct 
A) competitive 
B) noncompetitive 
C) irreversible 
D) more than one response is correct

Question 16

The region of an enzyme where the substrate molecule fits is called the

Accepted Answer

A) active site. 
B) substrate site. 
C) substrate bond. 
D) primary site. 
A) active site. 
B) substrate site. 
C) substrate bond. 
D) primary site.

Question 17

Which of the following describes the significance of the term Vmax ?

Accepted Answer

A) how rapidly a substrate molecule can travel to an enzyme 
B) the maximum rate that an enzyme can process substrate species 
C) the velocity at which the enzyme and substrate must collide for activation 
D) the maximum speed at which product molecules leave the binding site. 
A) how rapidly a substrate molecule can travel to an enzyme 
B) the maximum rate that an enzyme can process substrate species 
C) the velocity at which the enzyme and substrate must collide for activation 
D) the maximum speed at which product molecules leave the binding site.

Question 18

Noncompetitive inhibitors bind strongly to the active site.

Accepted Answer

A) True 
 B)False

Question 19

Which of the following enzyme properties is explained by the lock-and-key model?

Accepted Answer

A) specificity 
B) high turnover rate 
C) high molecular weight 
D) susceptibility to denaturation 
A) specificity 
B) high turnover rate 
C) high molecular weight 
D) susceptibility to denaturation

Question 20

An enzyme is operating at its optimum pH.If the pH were increased,how would the rate of the enzyme-catalyzed reaction change?

Accepted Answer

A) increase 
B) decrease 
C) could increase or decrease 
D) would not change 
A) increase 
B) decrease 
C) could increase or decrease 
D) would not change

Exam 20: Enzymes

Heavy metal ions are believed to act as ____ inhibitors.

Which of the following enzyme types have proven especially useful in diagnostic medicine?

Enzymes have specific temperature and pH ranges within which they function best.

The catalytically inactive form of an enzyme is called a(n)_____ .

An enzyme is known to catalyze the conversion of proteins to amino acids.Which of the following would be a correct designation for the enzyme?

What type of enzyme would catalyze the following reaction?

An irreversible inhibitor usually forms a covalent bond with the enzyme.

When enzyme activity is graphed versus the following,which graph is a straight line?

Insulin is initially produced as proinsulin,an inactive form that contains extra amino acid residues.Proinsulin must be an apoenzyme.

While most enzymes increase the rate of a reaction by providing a new mechanism with a lower activation energy,there are several examples where they can also increase the activation energy and slow down or stop a reaction.

What is the function of an inhibitor?

Many drugs act as competitive inhibitors.

The general term which refers to the catalytic ability of an enzyme is

Consider the following figure.The step labeled A is known to reduce the activity of Enzyme 1.This would be described as what type of enzyme regulation?

Sulfa drugs prevent bacterial growth by acting as ____ inhibitors.

The region of an enzyme where the substrate molecule fits is called the

Which of the following describes the significance of the term Vmax ?

Noncompetitive inhibitors bind strongly to the active site.

Which of the following enzyme properties is explained by the lock-and-key model?

An enzyme is operating at its optimum pH.If the pH were increased,how would the rate of the enzyme-catalyzed reaction change?

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Which of the following describes the significance of the term V_max ?