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BIOC 384 Exam 2 Questions & Answers, Well
Elaborated | Already Verified Test |100% Verified
solutions | 2025\2026 Latest!!
An enzyme has a single active site at which it can bind and
hydrolyze either X or Y; however, the enzyme cannot bind X and Y
at the same time. Answer the following questions regarding the
Km and the Vmax of this enzyme. Choose a total of three
answers, one for each question A, B, and C.
A) Will the apparent Km for X be affect if Y is present in the
reaction mixture?
B) Will Vmax for X be affected if Y is present in the reaction
mixture?
C) Is it possible for Vmax and Vmax/Km to show a different
dependence on pH? - . . ANSWER ✓✓ A. yes
B. no
C. yes
An enzyme undergoes a mutation that causes it to lose the ability
to be regulated via phosphorylation. Which of the following
mutations may lead to this loss of regulation? Assume that the
overall structure is not altered by the mutation. - . . ANSWER
✓✓ Tyr --> Phe
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An experiment is performed in which the kinetics of an enzyme-
catalyzed reaction at different pHs is monitored. It is found that
the Km does not change but that the kcat increases as the pH
goes above 7. Which of the following is true? - . . ANSWER ✓✓ A
chemical group within the enzyme that has a pKa of around 7 is
likely involved in the catalytic mechanism.
Answer the following questions about the graph shown at the
right. - . . ANSWER ✓✓ (1) protein A
(2) protein A
(3) protein B
(4) protein A
(5) protein B
(6) protein A
Assume that in the graph at the right, the curve represented by Y
is normal adult hemoglobin at pH 7.4 with normal levels of 2,3-
BPG. Which of the statements below is the most correct
regarding curves X and Z? - . . ANSWER ✓✓ Z represents O2
binding in cells with elevated 2,3-BPG, whereas X represents O2
binding in cells with decrease 2,3-BPG.
Below is a fractional saturation curve for O2 binding to adult
hemoglobin. Assume that curve Y represents a system at pH 7.4
and with a normal physiological level of 2,3-BPG. Curve X
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represents a system that: - . . ANSWER ✓✓ has a higher pH with
a normal physiological level of 2,3-BPG
Binding of the negatively charge allosteric effector 2,3-
bisphosphoglycerate (2,3-BPG) stabilizes the T state of
hemoglobin. A lysine residue in the central cavity of hemoglobin
interacts with 2,3-BPG. In a hemoglobin variant, there is a
substitution of this lysine by an asparagine. Relative to the wild-
type hemoglobin, this variant would be expected to have. Choose
the ONE most correct statement. - . . ANSWER ✓✓ An increased
affinity for oxygen in the presence of 2,3-BPG, and an equivalent
affinity in the absence of 2,3-BPG.
(Fill in the blank) Chymotrypsin is a serine protease requiring ... -
. . ANSWER ✓✓ covalent, acid-base, carboxyl, donating,
nucleophile, carbonyl carbon, Gly193
A conformational change in troponin that opens the myosin-
binding sites on actin is triggered by the: - . . ANSWER ✓✓
release of Ca2+ by the sarcoplasmic reticulum
A mixture of enzyme and inhibitor is run through a size-
exclusion chromatography column. The activity of the enzyme is
assessed before and after the chromatography. The enzyme has
more activity after the chromatography step. Which of the
following is true? - . . ANSWER ✓✓ the inhibitor is a reversible
inhibitor
BIOC 384 Exam 2 Questions & Answers, Well
Elaborated | Already Verified Test |100% Verified
solutions | 2025\2026 Latest!!
An enzyme has a single active site at which it can bind and
hydrolyze either X or Y; however, the enzyme cannot bind X and Y
at the same time. Answer the following questions regarding the
Km and the Vmax of this enzyme. Choose a total of three
answers, one for each question A, B, and C.
A) Will the apparent Km for X be affect if Y is present in the
reaction mixture?
B) Will Vmax for X be affected if Y is present in the reaction
mixture?
C) Is it possible for Vmax and Vmax/Km to show a different
dependence on pH? - . . ANSWER ✓✓ A. yes
B. no
C. yes
An enzyme undergoes a mutation that causes it to lose the ability
to be regulated via phosphorylation. Which of the following
mutations may lead to this loss of regulation? Assume that the
overall structure is not altered by the mutation. - . . ANSWER
✓✓ Tyr --> Phe
,2|Page
An experiment is performed in which the kinetics of an enzyme-
catalyzed reaction at different pHs is monitored. It is found that
the Km does not change but that the kcat increases as the pH
goes above 7. Which of the following is true? - . . ANSWER ✓✓ A
chemical group within the enzyme that has a pKa of around 7 is
likely involved in the catalytic mechanism.
Answer the following questions about the graph shown at the
right. - . . ANSWER ✓✓ (1) protein A
(2) protein A
(3) protein B
(4) protein A
(5) protein B
(6) protein A
Assume that in the graph at the right, the curve represented by Y
is normal adult hemoglobin at pH 7.4 with normal levels of 2,3-
BPG. Which of the statements below is the most correct
regarding curves X and Z? - . . ANSWER ✓✓ Z represents O2
binding in cells with elevated 2,3-BPG, whereas X represents O2
binding in cells with decrease 2,3-BPG.
Below is a fractional saturation curve for O2 binding to adult
hemoglobin. Assume that curve Y represents a system at pH 7.4
and with a normal physiological level of 2,3-BPG. Curve X
, 3|Page
represents a system that: - . . ANSWER ✓✓ has a higher pH with
a normal physiological level of 2,3-BPG
Binding of the negatively charge allosteric effector 2,3-
bisphosphoglycerate (2,3-BPG) stabilizes the T state of
hemoglobin. A lysine residue in the central cavity of hemoglobin
interacts with 2,3-BPG. In a hemoglobin variant, there is a
substitution of this lysine by an asparagine. Relative to the wild-
type hemoglobin, this variant would be expected to have. Choose
the ONE most correct statement. - . . ANSWER ✓✓ An increased
affinity for oxygen in the presence of 2,3-BPG, and an equivalent
affinity in the absence of 2,3-BPG.
(Fill in the blank) Chymotrypsin is a serine protease requiring ... -
. . ANSWER ✓✓ covalent, acid-base, carboxyl, donating,
nucleophile, carbonyl carbon, Gly193
A conformational change in troponin that opens the myosin-
binding sites on actin is triggered by the: - . . ANSWER ✓✓
release of Ca2+ by the sarcoplasmic reticulum
A mixture of enzyme and inhibitor is run through a size-
exclusion chromatography column. The activity of the enzyme is
assessed before and after the chromatography. The enzyme has
more activity after the chromatography step. Which of the
following is true? - . . ANSWER ✓✓ the inhibitor is a reversible
inhibitor
