Question 1

A type of enzyme regulation,where a product acts as an inhibitor molecule,is called ___ inhibition.

Accepted Answer

A)  feedback 
B)  end product 
C)  competitive 
D)  zymogenic 
A)  feedback 
B)  end product 
C)  competitive 
D)  zymogenic

Question 2

The EC name of an enzyme is alanine transaminase.This indicates that

Accepted Answer

A)  the substrate is alanine. 
B)  the functional group is an amine. 
C)  the type of reaction is a transfer. 
D)  All of the above. 
A)  the substrate is alanine. 
B)  the functional group is an amine. 
C)  the type of reaction is a transfer. 
D)  All of the above.

Question 3

An enzyme useful in diagnosing leukemia is _____ .

Accepted Answer

A)  CK 
B)  acid phosphatase 
C)  lysozyme 
D)  LDH 
A)  CK 
B)  acid phosphatase 
C)  lysozyme 
D)  LDH

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

Which statement about enzymes is incorrect?

Accepted Answer

A)  Enzymes can either speed up or slow down a chemical reaction. 
B)  Enzymes are not used up during the reaction in which they are involved. 
C)  Enzymes are proteins that are capable of reducing the activation energy. 
D)  There are enzymes that interact with one enantiomer,but not the other. 
A)  Enzymes can either speed up or slow down a chemical reaction. 
B)  Enzymes are not used up during the reaction in which they are involved. 
C)  Enzymes are proteins that are capable of reducing the activation energy. 
D)  There are enzymes that interact with one enantiomer,but not the other.

Question 6

The toxicity of cyanide is due to its affinity for the

Accepted Answer

A)  (-SH groups of enzymes.) 
B)  carboxyl groups of active sites. 
C)  iron atoms of cytochrome oxidase. 
D)  amino groups of hemoglobin. 
A)  (-SH groups of enzymes.) 
B)  carboxyl groups of active sites. 
C)  iron atoms of cytochrome oxidase. 
D)  amino groups of hemoglobin.

Question 7

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 8

An ACE inhibitor is a medication that is used to block the activity of angiotensin-converting enzymes,helping to reduce blood pressure.

Accepted Answer

A) True 
 B)False

Question 9

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 10

In an enzyme assay,4.5 $\mu$ mol of substrate was consumed in 3.166 min.What is the enzyme activity expressed in IU?

Accepted Answer

A)  4.5 IU 
B)  14 IU 
C)  0.70 IU 
D)  1.4 IU 
A)  4.5 IU 
B)  14 IU 
C)  0.70 IU 
D)  1.4 IU

Question 11

How does a zymogen differ from an apoenzyme?

Accepted Answer

A)  An apoenzyme is deactivated by a cofactor. 
B)  A zymogen is initially lacking an active site. 
C)  A zymogen is activated by removing part of its structure. 
D)  An apoenzyme is produced from a holoenzyme + coenzyme 
A)  An apoenzyme is deactivated by a cofactor. 
B)  A zymogen is initially lacking an active site. 
C)  A zymogen is activated by removing part of its structure. 
D)  An apoenzyme is produced from a holoenzyme + coenzyme

Question 12

The theory that proposes a somewhat flexible enzyme conformation is the

Accepted Answer

A)  lock-and-key theory. 
B)  induced-fit theory. 
C)  physically-fit theory. 
D)  expanding-fit theory. 
A)  lock-and-key theory. 
B)  induced-fit theory. 
C)  physically-fit theory. 
D)  expanding-fit theory.

Question 13

In the diagram,which number would represent Vmax?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  either 2 or 3 
A)  1 
B)  2 
C)  3 
D)  either 2 or 3

Question 14

Which statement does not apply to the lock and key theory?

Accepted Answer

A)  It explains the functioning of enzymes. 
B)  It explains the need for a specific three dimensional structure found in proteins. 
C)  It explains the reason why a particular enzyme is involved with one substrate. 
D)  It explains why a substrate-enzyme complex is so difficult to separate. 
A)  It explains the functioning of enzymes. 
B)  It explains the need for a specific three dimensional structure found in proteins. 
C)  It explains the reason why a particular enzyme is involved with one substrate. 
D)  It explains why a substrate-enzyme complex is so difficult to separate.

Question 15

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 16

Trypsin is an example of a proenzyme.

Accepted Answer

A) True 
 B)False

Question 17

____ would be considered as a common rate of chemical reaction measure per minute due to the presence of an enzyme.

Accepted Answer

A)  100 
B)  1,000 
C)  10,000 
D)  100,000 
A)  100 
B)  1,000 
C)  10,000 
D)  100,000

Question 18

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 19

A zymogen is correctly classified as a(n)

Accepted Answer

A)  organic cofactor for an enzyme. 
B)  inorganic cofactor for an enzyme. 
C)  coenzyme. 
D)  inactive form of an enzyme. 
A)  organic cofactor for an enzyme. 
B)  inorganic cofactor for an enzyme. 
C)  coenzyme. 
D)  inactive form of an enzyme.

Question 20

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

Exam 20: Enzymes

A type of enzyme regulation,where a product acts as an inhibitor molecule,is called ___ inhibition.

The EC name of an enzyme is alanine transaminase.This indicates that

An enzyme useful in diagnosing leukemia is _____ .

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

Which statement about enzymes is incorrect?

The toxicity of cyanide is due to its affinity for the

What is the function of an inhibitor?

An ACE inhibitor is a medication that is used to block the activity of angiotensin-converting enzymes,helping to reduce blood pressure.

What type of enzyme would catalyze the following reaction?

In an enzyme assay,4.5 μ\muμ mol of substrate was consumed in 3.166 min.What is the enzyme activity expressed in IU?

How does a zymogen differ from an apoenzyme?

The theory that proposes a somewhat flexible enzyme conformation is the

In the diagram,which number would represent Vmax?

Which statement does not apply to the lock and key theory?

Heavy metal ions are believed to act as ____ inhibitors.

Trypsin is an example of a proenzyme.

____ would be considered as a common rate of chemical reaction measure per minute due to the presence of an enzyme.

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?

A zymogen is correctly classified as a(n)

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

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In an enzyme assay,4.5 $\mu$ mol of substrate was consumed in 3.166 min.What is the enzyme activity expressed in IU?

In the diagram,which number would represent V_max?