Question 1

Determine the KM and Vmax from the following graph. (Note: On the x-axis the minor tick mark spacing is 0.005; on the y-axis the minor tick mark spacing is 0.002)

Accepted Answer

A)  KM = [0.006]; Vmax = 0.0075/s 
B)  KM = [0.196]; Vmax = 0.0075/s 
C)  KM = [165]; Vmax = 33/s 
D)  KM = [33]; Vmax = 167/s 
E)  KM = [270]; Vmax x = 68/s 
A)  KM = [0.006]; Vmax = 0.0075/s 
B)  KM = [0.196]; Vmax = 0.0075/s 
C)  KM = [165]; Vmax = 33/s 
D)  KM = [33]; Vmax = 167/s 
E)  KM = [270]; Vmax x = 68/s

Question 2

An extremely efficient enzyme has a _____ KM and a _____ kcat.

Accepted Answer

A)  small; small 
B)  small; large 
C)  large; large 
D)  large; small 
E)  kcat and KM do nothing to predict the efficiency of an enzyme 
A)  small; small 
B)  small; large 
C)  large; large 
D)  large; small 
E)  kcat and KM do nothing to predict the efficiency of an enzyme

Question 3

If a Lineweaver-Burk plot gave a line with an equation of y = 0.490 x + 0.059, what is the velocity at a substrate concentration of 5 mM? The original units for substrate were in mM and velocity in mM/s.

Accepted Answer

A)  0.288 mM/s 
B)  0.399 mM/s 
C)  2.51 mM/s 
D)  6.37 mM/s 
E)  the velocity cannot be determined from these data 
A)  0.288 mM/s 
B)  0.399 mM/s 
C)  2.51 mM/s 
D)  6.37 mM/s 
E)  the velocity cannot be determined from these data

Question 4

Chymotrypsin catalyzes the hydrolysis of peptide bonds adjacent to _____ residues in a peptide.

Accepted Answer

A)  neutral polar 
B)  nonpolar 
C)  negatively charged 
D)  positively charged 
E)  all of the above because chymotrypsin has little substrate specificity 
A)  neutral polar 
B)  nonpolar 
C)  negatively charged 
D)  positively charged 
E)  all of the above because chymotrypsin has little substrate specificity

Question 5

If an enzyme-catalyzed reaction with a KM of 3.5 mM has a velocity of 5 mM/min at a substrate concentration of 0.5 mM, what is the Vmax?

Accepted Answer

A)  0.625 mM/min 
B)  15 mM/min 
C)  17.5 mM/min 
D)  35 mM/min 
E)  40 mM/min 
A)  0.625 mM/min 
B)  15 mM/min 
C)  17.5 mM/min 
D)  35 mM/min 
E)  40 mM/min

Question 6

Which of the following expresses the velocity for an enzyme-catalyzed reaction that obeys Michaelis-Menten kinetics?

Accepted Answer

A)  v = k1[E][S] 
B)  v = k1[E][S] - k-1[ES] 
C)  v = k1[E][S] + k2[ES] 
D)  v = k2[ES] 
E)  v = k2[ES] - k-1[ES] 
A)  v = k1[E][S] 
B)  v = k1[E][S] - k-1[ES] 
C)  v = k1[E][S] + k2[ES] 
D)  v = k2[ES] 
E)  v = k2[ES] - k-1[ES]

Question 7

Which of the following amino acids would most likely be found in the active site of an enzyme that uses acid-base catalysis?

Accepted Answer

A)  Asn 
B)  Ser 
C)  Met 
D)  His 
E)  Trp 
A)  Asn 
B)  Ser 
C)  Met 
D)  His 
E)  Trp

Question 8

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-1 2. 
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-1 2. 
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.

Question 9

A reversible inhibitor that binds to the enzyme only after one substrate has bound is a _____.

Accepted Answer

A)  noncompetitive inhibitor 
B)  uncompetitive inhibitor 
C)  competitive inhibitor 
D)  allosteric inhibitor 
E)  suicide substrate 
A)  noncompetitive inhibitor 
B)  uncompetitive inhibitor 
C)  competitive inhibitor 
D)  allosteric inhibitor 
E)  suicide substrate

Question 10

Chymotrypsin catalyzes the hydrolysis of a peptide bond and is therefore categorized as a(n) _____.

Accepted Answer

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

Question 11

The molecule chymotrypsinogen is known as a(n) _____.

Accepted Answer

A)  apoenzyme 
B)  holoenzyme 
C)  protease inhibitor 
D)  zymogen 
E)  none of the above 
A)  apoenzyme 
B)  holoenzyme 
C)  protease inhibitor 
D)  zymogen 
E)  none of the above

Question 12

refer to the overall transformation shown in the following reaction:  
-For the reaction, the steady state assumption _____.

Accepted Answer

A)  implies that k1 = k-1 
B)  implies that k-1 and k2 are such that the [ES] = k1[ES] 
C)  [P]>>[E] 
D)  [S] = [P] 
E)  ES breakdown occurs at the same rate as ES formation 
A)  implies that k1 = k-1 
B)  implies that k-1 and k2 are such that the [ES] = k1[ES] 
C)  [P]>>[E] 
D)  [S] = [P] 
E)  ES breakdown occurs at the same rate as ES formation

Question 13

Which of the following must be true if the steady state assumption is to be used?

Accepted Answer

A)  [E]T = [ES] 
B)  (k2 - k-1) / k1 = 1 
C)  k1[E][S] = k2[ES] 
D)  k1[E][S] = k2[ES] - k-1[ES] 
E)  d[ES] / dt = 0 
A)  [E]T = [ES] 
B)  (k2 - k-1) / k1 = 1 
C)  k1[E][S] = k2[ES] 
D)  k1[E][S] = k2[ES] - k-1[ES] 
E)  d[ES] / dt = 0

Question 14

A common type of covalent modification of regulatory enzymes involves _____ of serine residues.

Accepted Answer

The answer of A common type of covalent modification of...

Question 15

A Lineweaver-Burk plot is a _____.

Accepted Answer

A)  double reciprocal plot 
B)  Michaelis-Menten plot 
C)  sigmoidal plot 
D)  hyperbolic plot 
E)  logarithmic plot 
A)  double reciprocal plot 
B)  Michaelis-Menten plot 
C)  sigmoidal plot 
D)  hyperbolic plot 
E)  logarithmic plot

Question 16

If an enzyme-catalyzed reaction has a velocity of 2 mM/min and a Vmax of 10 mM/min when the substrate concentration is 0.5 mM, what is the KM?

Accepted Answer

A)  0.2 mM 
B)  0.5 mM 
C)  1 mM 
D)  2 mM 
E)  5 mM 
A)  0.2 mM 
B)  0.5 mM 
C)  1 mM 
D)  2 mM 
E)  5 mM

Question 17

Which of the following types of inhibition can be reversed by addition of more substrate?

Accepted Answer

A)  noncompetitive inhibition 
B)  competitive inhibition 
C)  uncompetitive inhibition 
D)  irreversible inhibition 
E)  none of the above 
A)  noncompetitive inhibition 
B)  competitive inhibition 
C)  uncompetitive inhibition 
D)  irreversible inhibition 
E)  none of the above

Question 18

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

Accepted Answer

The answer of If A $\rightarrow$ B is a zero-order...

Question 19

Based on the figure below, 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 
A)  A = KM 
B)  KM = A/2 
C)  B = KM 
D)  C = -KM 
E)  D= 1/KM

Question 20

Which of the following statements regarding allosteric enzymes is true?

Accepted Answer

A)  They are always oligomeric. 
B)  They are generally found at regulatory sites in metabolic pathways. 
C)  They are subject to regulation by both positive and negative effectors. 
D)  A plot of velocity versus [substrate] often yields a sigmoidal curve. 
E)  All of the above 
A)  They are always oligomeric. 
B)  They are generally found at regulatory sites in metabolic pathways. 
C)  They are subject to regulation by both positive and negative effectors. 
D)  A plot of velocity versus [substrate] often yields a sigmoidal curve. 
E)  All of the above

Exam 4: Proteins Iienzymes

Determine the KM and Vmax from the following graph. (Note: On the x-axis the minor tick mark spacing is 0.005; on the y-axis the minor tick mark spacing is 0.002)

An extremely efficient enzyme has a _____ KM and a _____ kcat.

If a Lineweaver-Burk plot gave a line with an equation of y = 0.490 x + 0.059, what is the velocity at a substrate concentration of 5 mM? The original units for substrate were in mM and velocity in mM/s.

Chymotrypsin catalyzes the hydrolysis of peptide bonds adjacent to _____ residues in a peptide.

If an enzyme-catalyzed reaction with a KM of 3.5 mM has a velocity of 5 mM/min at a substrate concentration of 0.5 mM, what is the Vmax?

Which of the following expresses the velocity for an enzyme-catalyzed reaction that obeys Michaelis-Menten kinetics?

Which of the following amino acids would most likely be found in the active site of an enzyme that uses acid-base catalysis?

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

A reversible inhibitor that binds to the enzyme only after one substrate has bound is a _____.

Chymotrypsin catalyzes the hydrolysis of a peptide bond and is therefore categorized as a(n) _____.

The molecule chymotrypsinogen is known as a(n) _____.

refer to the overall transformation shown in the following reaction: -For the reaction, the steady state assumption _____.

Which of the following must be true if the steady state assumption is to be used?

A common type of covalent modification of regulatory enzymes involves _____ of serine residues.

A Lineweaver-Burk plot is a _____.

If an enzyme-catalyzed reaction has a velocity of 2 mM/min and a Vmax of 10 mM/min when the substrate concentration is 0.5 mM, what is the KM?

Which of the following types of inhibition can be reversed by addition of more substrate?

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

Based on the figure below, which of the following expressions would correctly define KM?

Which of the following statements regarding allosteric enzymes is true?

The Chemical Foundations of Biochemistry

Nucleic Acids

Proteins I

Membranes and an Introduction to Signal Transduction

Carbohydrates I

The Common Catabolic Pathway

Carbohydrates II

Lipids I

Lipids II

Amine Metabolism

Metabolism Integration

Nucleotide Deoxynucleotide Metabolism

Dna Replication, Damage and Repair

Rna Synthesis

Protein

Control of Gene

Determination of Macromolecular Structure

Allosterism and Receptor-Ligand

Designer Proteins and Protein Folding

Biomolecule Purification

Bioinformatics and Omics

Signal

Protein Trafficking

Photosynthesis Nitrogen

Filters

Determine the K_M and V_max from the following graph. (Note: On the x-axis the minor tick mark spacing is 0.005; on the y-axis the minor tick mark spacing is 0.002)

An extremely efficient enzyme has a _____ K_M and a _____ k_cat.

If an enzyme-catalyzed reaction with a K_M of 3.5 mM has a velocity of 5 mM/min at a substrate concentration of 0.5 mM, what is the V_max?

If an enzyme-catalyzed reaction has a velocity of 2 mM/min and a V_max of 10 mM/min when the substrate concentration is 0.5 mM, what is the K_M?

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

Based on the figure below, which of the following expressions would correctly define K_M?