Question 1

Protein kinases are involved in

Accepted Answer

A) the digestion of drugs to potentially toxic byproducts. 
B) the degradation of enzymes to the component amino acids. 
C) the phosphorylation of a wide variety of proteins. 
D) the metabolism of drugs to water soluble,excretable compounds. 
E) all of the above 
A) the digestion of drugs to potentially toxic byproducts. 
B) the degradation of enzymes to the component amino acids. 
C) the phosphorylation of a wide variety of proteins. 
D) the metabolism of drugs to water soluble,excretable compounds. 
E) all of the above

Question 2

When [S] = KM,$v$0 = (_____)× (Vmax).

Accepted Answer

A) [S] 
B) 0.75 
C) 0.5 
D) KM 
E) kcat 
A) [S] 
B) 0.75 
C) 0.5 
D) KM 
E) kcat

Question 3

Compounds that function as "mixed inhibitors"
(I)interfere with substrate binding to the enzyme.
(II)bind to the enzyme reversibly.
(III)can bind to the enzyme/substrate complex.

Accepted Answer

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

Question 4

Matching

-If A$\to$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] 
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 5

Enzyme E is responsible for conversion of substrate X to product U.As a result of this conversion electrons are transported to a coenzyme (FAD)within Enzyme E.In order for the reaction to be completed,a second substrate NAD+ must also bind Enzyme E and collect stored electrons (which converts it to product,NADH).The graph below shows the data while varying X,with fixed concentrations of NAD+.What type of multi-substrate mechanism does enzyme E utilize?  
Substrates: X NAD+
$\downarrow$$\downarrow$
Products: U NADH

Accepted Answer

A) sequential - Ordered 
B) sequential - Random 
C) simultaneous addition 
D) Ping Pong 
E) Sequential but the data cannot differentiate between ordered and random. 
A) sequential - Ordered 
B) sequential - Random 
C) simultaneous addition 
D) Ping Pong 
E) Sequential but the data cannot differentiate between ordered and random.

Question 6

Matching

-In ______,the inhibitor binds to a site involved in both substrate binding and catalysis.

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] 
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 7

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. 
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 8

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 
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 9

Enzyme activity in cells is controlled by which of the following?
(I)covalent modifications
(II)modulation of expression levels
(III)feedback inhibition
(IV)allosteric effectors

Accepted Answer

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

Question 10

Matching

-Different enzymes that catalyze the same reaction,although may be found in different tissues,are known as ______.

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] 
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 11

The breakdown of dopamine is catalyzed by the enzyme monoamine oxidase (MAO).What is the final concentration of product if the starting dopamine concentration is 0.050 M and the reaction runs for 5 seconds.(Assume the rate constant for the reaction is 0.249 s−1. )

Accepted Answer

A) 0)050 M 
B) 0)014 M 
C) 0)018 M 
D) 1)2 M 
E) 0)025 M 
A) 0)050 M 
B) 0)014 M 
C) 0)018 M 
D) 1)2 M 
E) 0)025 M

Question 12

I propose to design a new drug which will act as an inhibitor for an enzyme.If I have used all current information about the mechanism of this enzyme to design this inhibitor and I carefully engineer it with similar chemical properties of the transition state,what type of inhibitor am I attempting to engineer and how will I know if I have succeeded?

Accepted Answer

A) A competitive inhibitor,collect kinetic data both in the presence and absence of inhibitor and watch for a change in Vmax. 
B) A competitive inhibitor,collect kinetic data both in the presence and absence of inhibitor and watch for a change in KM. 
C) A uncompetitive inhibitor,collect kinetic data both in the presence and absence of inhibitor and watch for a change in KM. 
D) A uncompetitive inhibitor,collect kinetic data both in the presence and absence of inhibitor and watch for a change in Vmax. 
E) None of the above. 
A) A competitive inhibitor,collect kinetic data both in the presence and absence of inhibitor and watch for a change in Vmax. 
B) A competitive inhibitor,collect kinetic data both in the presence and absence of inhibitor and watch for a change in KM. 
C) A uncompetitive inhibitor,collect kinetic data both in the presence and absence of inhibitor and watch for a change in KM. 
D) A uncompetitive inhibitor,collect kinetic data both in the presence and absence of inhibitor and watch for a change in Vmax. 
E) None of the above.

Question 13

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

Question 14

At substrate concentrations much lower than the enzyme concentration,

Accepted Answer

A) the rate of reaction is expected to be inversely proportional to substrate concentration. 
B) the rate of reaction is expected to be directly proportional to substrate concentration. 
C) first order enzyme kinetics are not observed. 
D) the KM is lower. 
E) the rate of reaction is independent of substrate concentration. 
A) the rate of reaction is expected to be inversely proportional to substrate concentration. 
B) the rate of reaction is expected to be directly proportional to substrate concentration. 
C) first order enzyme kinetics are not observed. 
D) the KM is lower. 
E) the rate of reaction is independent of substrate concentration.

Question 15

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] 
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 16

Matching

-In uncompetitive inhibition,the inhibitor binds only to the ______.

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] 
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 17

Pseudo-first-order reaction kinetics would be observed for the reaction A + B $\to$ C

Accepted Answer

A) if [A] or [B] > [C]. 
B) if [C]>[A] and [C]>[B]. 
C) if [A] or [B] = 0. 
D) if [C] = 0. 
E) none of the above 
A) if [A] or [B] > [C]. 
B) if [C]>[A] and [C]>[B]. 
C) if [A] or [B] = 0. 
D) if [C] = 0. 
E) none of the above

Question 18

Based on the figures below,which of the following expressions would be correct?

Accepted Answer

A) Vmax = 1/B 
B) C = 1/ Vmax 
C) D= Vmax 
D) D = 1/ Vmax 
E) A = 1/ Vmax 
A) Vmax = 1/B 
B) C = 1/ Vmax 
C) D= Vmax 
D) D = 1/ Vmax 
E) A = 1/ Vmax

Question 19

________ clinical trials are focused on evaluating the efficacy of new drug candidates,and usually use _____ test.

Accepted Answer

A) Phase 1;single blind 
B) Phase 1;double blind 
C) Phase 2;single blind 
D) Phase 2;double blind 
E) Phase 3;double blind 
A) Phase 1;single blind 
B) Phase 1;double blind 
C) Phase 2;single blind 
D) Phase 2;double blind 
E) Phase 3;double blind

Question 20

The following questions refer to the overall transformation shown in the following reaction:  
-Which of the following is (are)true?

Accepted Answer

A) The [ES] will remain constant if k2>k1 and k−12. 
B) The reaction is zero order with respect to [S] if [S]>>[E] 
C) It describes a double displacement reaction 
D) All of the above are true. 
E) None of the above is true. 
A) The [ES] will remain constant if k2>k1 and k−12. 
B) The reaction is zero order with respect to [S] if [S]>>[E] 
C) It describes a double displacement reaction 
D) All of the above are true. 
E) None of the above is true.

Exam 12: Enzyme Kinetics, inhibition and Control

Protein kinases are involved in

When [S] = KM, vvv 0 = (_____)× (Vmax).

Compounds that function as "mixed inhibitors" (I)interfere with substrate binding to the enzyme. (II)bind to the enzyme reversibly. (III)can bind to the enzyme/substrate complex.

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

Matching -In ______,the inhibitor binds to a site involved in both substrate binding and catalysis.

A lead compound would be most promising if it had:

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?

Enzyme activity in cells is controlled by which of the following? (I)covalent modifications (II)modulation of expression levels (III)feedback inhibition (IV)allosteric effectors

Matching -Different enzymes that catalyze the same reaction,although may be found in different tissues,are known as ______.

The breakdown of dopamine is catalyzed by the enzyme monoamine oxidase (MAO).What is the final concentration of product if the starting dopamine concentration is 0.050 M and the reaction runs for 5 seconds.(Assume the rate constant for the reaction is 0.249 s−1. )

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

At substrate concentrations much lower than the enzyme concentration,

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

Matching -In uncompetitive inhibition,the inhibitor binds only to the ______.

Pseudo-first-order reaction kinetics would be observed for the reaction A + B →\to→ C

Based on the figures below,which of the following expressions would be correct?

________ clinical trials are focused on evaluating the efficacy of new drug candidates,and usually use _____ test.

The following questions refer to the overall transformation shown in the following reaction: -Which of the following is (are)true?

Introduction to the Chemistry of Life

Water

Nucleotides, nucleic Acids, and Genetic Information

Amino Acids

Proteins: Primary Structure

Proteins: Three-Dimensional Structure

Protein Function Part I: Myoglobin and Hemoglobin

Carbohydrates

Lipids and Biological Membranes

Membrane Transport

Enzyme Catalysis

Biochemical Signaling

Introduction to Metabolism

Glucose Catabolism

Glycogen Metabolism and Gluconeogenesis

Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Mammalian Fuel Metabolism: Integration and Regulation

Nucleotide Metabolism

Nucleic Acid Structure

DNA Replication, repair and Recombination

Transcription and Rna Processing

Protein Synthesis

Regulation of Gene Expression

Filters

When [S] = K_M, $v$ ₀= (_____)× (V_max).

Matching -If A $\to$ 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?

The breakdown of dopamine is catalyzed by the enzyme monoamine oxidase (MAO).What is the final concentration of product if the starting dopamine concentration is 0.050 M and the reaction runs for 5 seconds.(Assume the rate constant for the reaction is 0.249 s⁻¹. )

Pseudo-first-order reaction kinetics would be observed for the reaction A + B $\to$ C

____ clinical trials are focused on evaluating the efficacy of new drug candidates,and usually use _ test.