Question 1

Matching
-The type of enzyme inhibition in which Vmax is unaffected is ______.

Accepted Answer

A) isozymes 
B) [A] 
C) the rate constant 
D) Ping Pong 
E) bimolecular
F)ES complex
G)random ordered
H)competitive inhibition
I)unimolecular
J)[A]²
K)Competitive inhibition
L)phosphorylation
M)small KS
N)large KS
O)uncompetitive inhibition
P)[B]

Question 2

Learning objective: Reaction Kinetics
The following questions refer to the diagram (with boxes where it has been left incomplete): 
-A compound that distorts the active site, rendering the enzyme catalytically inactive is called

Accepted Answer

A) a uncompetitive inhibitor 
B) an allosteric effector 
C) an inactivator 
D) a competitive inhibitor 
E) none of the above

Question 3

Following several experiments, the data presented on the graph below was obtained.What can you determine from this graph?

Accepted Answer

A) This data may have been collected both in the absence (solid line)and presence (dashed line)of a competitive inhibitor. 
B) This data may have been collected both in the absence (solid line)and presence (dashed line)of a mixed (noncompetitive)inhibitor. 
C) This data may have been collected both in the absence (solid line)and presence (dashed line)of mechanism based inhibitor. 
D) This data may have been collected both in the absence (solid line)and presence (dashed line)of an inhibitor which binds the active site. 
E) More than one of the above are correct.

Question 4

Find kcat for a reaction in which Vmax is 4 × 10-4 mol•min-1 and the reaction mixture contains one microgram of enzyme (the molecular weight of the enzyme is 200,000D).

Accepted Answer

A) 2 × 10-11 min-1 
B) 8 × 107 min-1 
C) 8 × 109 min-1 
D) 2 × 10-14 min-1

Question 5

Matching
-If A$\rarr$B is a zero-order reaction, the rate is dependent on ______.

Accepted Answer

A) isozymes 
B) [A] 
C) the rate constant 
D) Ping Pong 
E) bimolecular
F)ES complex
G)random ordered
H)competitive inhibition
I)unimolecular
J)[A]²
K)Competitive inhibition
L)phosphorylation
M)small KS
N)large KS
O)uncompetitive inhibition
P)[B]

Question 6

What is the velocity of a first-order reaction at 37oC when the reactant concentration is 6 × 10-2 M and the rate constant is 8 × 103 sec-1?

Accepted Answer

A) 1.33 × 105 M-1•sec-1 
B) 1.33 × 105 M•sec 
C) 7.5 × 10-2 M•sec 
D) 4.8 × 102 M•sec-1 
E) Not enough data are given to make this calculation

Question 7

[S] = KM for a simple enzymatic reaction.When [S] is doubled the initial velocity is

Accepted Answer

A) 2 Vmax 
B) equal to Vmax 
C) (1/3)Vmax 
D) 0.5 Vmax 
E) 2 KM/[S]

Question 8

The following questions refer to the overall transformation shown in the following reaction: 
-The Michaelis constant KM is defined as
I.(k-1 + k2)/k1
II.½ Vmax
III.[S] = [ES]
IV.[ES]/2

Accepted Answer

A) I 
B) I, II 
C) II 
D) I, IV 
E) II, IV

Question 9

Matching
-A two-substrate enzymatic reaction in which one product is produced before the second substrate binds to the enzyme has a ______ mechanism.

Accepted Answer

A) isozymes 
B) [A] 
C) the rate constant 
D) Ping Pong 
E) bimolecular
F)ES complex
G)random ordered
H)competitive inhibition
I)unimolecular
J)[A]²
K)Competitive inhibition
L)phosphorylation
M)small KS
N)large KS
O)uncompetitive inhibition
P)[B]

Question 10

Based on the figure in the question above (question 54), which of the following expressions would correctly define KM?

Accepted Answer

A) A= KM 
B) KM = A/2 
C) B = KM 
D) C = - KM 
E) D= 1/ KM

Question 11

A lead compound would be most promising if it had:

Accepted Answer

A) KI = 4.7 × 105 M. 
B) KI = 1.5 × 108 M. 
C) KI = 1.5 × 10-8 M. 
D) KI = 4.7 × 10-5 M. 
E) KM = 4.7 × 105 M.

Question 12

A lab recently developed a new drug which is hypothesized to inhibit the enzyme cyclooxygenase-2 (COX-2)and reduce inflammation.In their first test they monitored the reaction of substrate as it is converted to product in the presence of the new drug (data shown below).If the hypothesis is correct the observed initial rate will be at least 2 times slower than the normal reaction without the drug.If the normal initial rate is 30 mM/s, does the data below indicate that the team has designed a successful inhibitor?

Accepted Answer

A) Yes. 
B) No. 
C) This cannot be determined with the information given. 
D) The data is dependent on the maximal velocity. 
E) The answer is dependent on the substrate concentration.

Question 13

Irreversible enzyme inhibitors

Accepted Answer

A) inactivate the enzyme 
B) inhibit competitively 
C) maximize product by minimizing ES$\rarr$E+S 
D) behave allosterically 
E) function via Ping Pong mechanism

Question 14

KM

Accepted Answer

A) is the concentration of substrate where the enzyme achieves ½ Vmax. 
B) is equal to Ks. 
C) measures the stability of the product 
D) is high if the enzyme has high affinity for the substrate. 
E) All of the above are correct.

Question 15

Fourth-order reactions.

Accepted Answer

A) have three or more sequential rate determining steps. 
B) require a 'Ping Pong' mechanism. 
C) are best analyzed using Lineweaver-Burk plots. 
D) exist only when enzymatically catalyzed. 
E) none of the above.

Exam 12: Enzyme Kinetics, Inhibition and Control

Matching -The type of enzyme inhibition in which V_max is unaffected is ______.

Learning objective: Reaction Kinetics The following questions refer to the diagram (with boxes where it has been left incomplete) : -A compound that distorts the active site, rendering the enzyme catalytically inactive is called

Following several experiments, the data presented on the graph below was obtained.What can you determine from this graph?

Find k_cat for a reaction in which V_max is 4 × 10^-4 mol•min^-1 and the reaction mixture contains one microgram of enzyme (the molecular weight of the enzyme is 200,000D) .

Matching -If A $\rarr$ B is a zero-order reaction, the rate is dependent on ______.

What is the velocity of a first-order reaction at 37^oC when the reactant concentration is 6 × 10^-2 M and the rate constant is 8 × 10³ sec^-1?

[S] = K_M for a simple enzymatic reaction.When [S] is doubled the initial velocity is

The following questions refer to the overall transformation shown in the following reaction: -The Michaelis constant K_M is defined as I.(k_-1+ k₂) /k₁ II.½ V_max III.[S] = [ES] IV.[ES]/2

Matching -A two-substrate enzymatic reaction in which one product is produced before the second substrate binds to the enzyme has a ______ mechanism.

Based on the figure in the question above (question 54) , which of the following expressions would correctly define K_M?

A lead compound would be most promising if it had:

Irreversible enzyme inhibitors

K_M

Fourth-order reactions.

Exam 12: Enzyme Kinetics, Inhibition and Control

Matching -The type of enzyme inhibition in which Vmax is unaffected is ______.

Learning objective: Reaction Kinetics The following questions refer to the diagram (with boxes where it has been left incomplete) : -A compound that distorts the active site, rendering the enzyme catalytically inactive is called

Following several experiments, the data presented on the graph below was obtained.What can you determine from this graph?

Find kcat for a reaction in which Vmax is 4 × 10-4 mol•min-1 and the reaction mixture contains one microgram of enzyme (the molecular weight of the enzyme is 200,000D) .

Matching -If A →\rarr→ B is a zero-order reaction, the rate is dependent on ______.

What is the velocity of a first-order reaction at 37oC when the reactant concentration is 6 × 10-2 M and the rate constant is 8 × 103 sec-1?

[S] = KM for a simple enzymatic reaction.When [S] is doubled the initial velocity is

The following questions refer to the overall transformation shown in the following reaction: -The Michaelis constant KM is defined as I.(k-1 + k2) /k1 II.½ Vmax III.[S] = [ES] IV.[ES]/2

Matching -A two-substrate enzymatic reaction in which one product is produced before the second substrate binds to the enzyme has a ______ mechanism.

Based on the figure in the question above (question 54) , which of the following expressions would correctly define KM?

A lead compound would be most promising if it had:

Irreversible enzyme inhibitors

KM

Fourth-order reactions.

Matching -The type of enzyme inhibition in which V_max is unaffected is ______.

Find k_cat for a reaction in which V_max is 4 × 10^-4 mol•min^-1 and the reaction mixture contains one microgram of enzyme (the molecular weight of the enzyme is 200,000D) .

Matching -If A $\rarr$ B is a zero-order reaction, the rate is dependent on ______.

What is the velocity of a first-order reaction at 37^oC when the reactant concentration is 6 × 10^-2 M and the rate constant is 8 × 10³ sec^-1?

[S] = K_M for a simple enzymatic reaction.When [S] is doubled the initial velocity is

The following questions refer to the overall transformation shown in the following reaction: -The Michaelis constant K_M is defined as I.(k_-1+ k₂) /k₁ II.½ V_max III.[S] = [ES] IV.[ES]/2

Based on the figure in the question above (question 54) , which of the following expressions would correctly define K_M?

K_M