CHEM 210 Module 2 | Biochemistry Exam Q&A | Portage
Learning
These are original practice questions written for study. They cover common CHEM 210
Module 2 | Biochemistry topics: enzyme kinetics, inhibition, regulation, bioenergetics,
glycolysis, TCA cycle, oxidative phosphorylation, and carbohydrate metabolism, with
clinical applications.
Question 1:
Enzymes are biological catalysts that:
A. Increase activation energy
B. Lower activation energy
C. Are consumed in reactions
D. Change reaction enthalpy
Correct answer: B
Rationale: Enzymes lower activation energy, speeding reactions without being
consumed.
Question 2:
The active site of an enzyme is:
A. The entire enzyme surface
B. A specific region where substrate binds
C. The nucleus
D. A lipid bilayer
Correct answer: B
Rationale: Substrates bind at the active site, a specific pocket or cleft.
Question 3:
Which model describes enzyme-substrate binding as a flexible fit?
A. Lock-and-key model
B. Induced-fit model
C. Fluid mosaic model
D. Watson-Crick model
Correct answer: B
Rationale: The induced-fit model proposes that the enzyme changes shape upon
substrate binding.
,Question 4:
The lock-and-key model describes:
A. Rigid complementary fit between enzyme and substrate
B. Flexible enzyme conformational change
C. Random substrate binding
D. Irreversible inhibition
Correct answer: A
Rationale: The lock-and-key model proposes a rigid, complementary fit.
Question 5:
Vmax is:
A. Maximum reaction rate at saturating substrate
B. Substrate concentration at half Vmax
C. Enzyme concentration
D. Inhibitor concentration
Correct answer: A
Rationale: Vmax is reached when all enzyme active sites are saturated.
Question 6:
Km is:
A. Substrate concentration at half Vmax
B. Maximum velocity
C. Inhibitor constant
D. Enzyme molar mass
Correct answer: A
Rationale: Km is the substrate concentration at which the reaction rate is half of Vmax.
Question 7:
A low Km indicates:
A. High enzyme affinity for substrate
B. Low enzyme affinity
C. No enzyme activity
D. Maximum velocity
Correct answer: A
Rationale: Lower Km means less substrate is needed to reach half Vmax.
, Question 8:
A high Km indicates:
A. Low enzyme affinity for substrate
B. High enzyme affinity
C. No enzyme activity
D. Maximum velocity
Correct answer: A
Rationale: Higher Km means more substrate is needed to reach half Vmax.
Question 9:
A Lineweaver-Burk plot is a:
A. Double reciprocal plot
B. Single reciprocal plot
C. Linear plot of rate vs. substrate
D. Logarithmic plot
Correct answer: A
Rationale: The Lineweaver-Burk plot graphs 1/V vs. 1/[S].
Question 10:
On a Lineweaver-Burk plot, the y-intercept represents:
A. 1/Vmax
B. Km
C. Vmax
D. Km/Vmax
Correct answer: A
Rationale: The y-intercept of the double reciprocal plot is 1/Vmax.
Question 11:
On a Lineweaver-Burk plot, the x-intercept represents:
A. −1/Km
B. 1/Km
C. Km
D. Vmax
Correct answer: A
Rationale: The x-intercept is −1/Km.
Learning
These are original practice questions written for study. They cover common CHEM 210
Module 2 | Biochemistry topics: enzyme kinetics, inhibition, regulation, bioenergetics,
glycolysis, TCA cycle, oxidative phosphorylation, and carbohydrate metabolism, with
clinical applications.
Question 1:
Enzymes are biological catalysts that:
A. Increase activation energy
B. Lower activation energy
C. Are consumed in reactions
D. Change reaction enthalpy
Correct answer: B
Rationale: Enzymes lower activation energy, speeding reactions without being
consumed.
Question 2:
The active site of an enzyme is:
A. The entire enzyme surface
B. A specific region where substrate binds
C. The nucleus
D. A lipid bilayer
Correct answer: B
Rationale: Substrates bind at the active site, a specific pocket or cleft.
Question 3:
Which model describes enzyme-substrate binding as a flexible fit?
A. Lock-and-key model
B. Induced-fit model
C. Fluid mosaic model
D. Watson-Crick model
Correct answer: B
Rationale: The induced-fit model proposes that the enzyme changes shape upon
substrate binding.
,Question 4:
The lock-and-key model describes:
A. Rigid complementary fit between enzyme and substrate
B. Flexible enzyme conformational change
C. Random substrate binding
D. Irreversible inhibition
Correct answer: A
Rationale: The lock-and-key model proposes a rigid, complementary fit.
Question 5:
Vmax is:
A. Maximum reaction rate at saturating substrate
B. Substrate concentration at half Vmax
C. Enzyme concentration
D. Inhibitor concentration
Correct answer: A
Rationale: Vmax is reached when all enzyme active sites are saturated.
Question 6:
Km is:
A. Substrate concentration at half Vmax
B. Maximum velocity
C. Inhibitor constant
D. Enzyme molar mass
Correct answer: A
Rationale: Km is the substrate concentration at which the reaction rate is half of Vmax.
Question 7:
A low Km indicates:
A. High enzyme affinity for substrate
B. Low enzyme affinity
C. No enzyme activity
D. Maximum velocity
Correct answer: A
Rationale: Lower Km means less substrate is needed to reach half Vmax.
, Question 8:
A high Km indicates:
A. Low enzyme affinity for substrate
B. High enzyme affinity
C. No enzyme activity
D. Maximum velocity
Correct answer: A
Rationale: Higher Km means more substrate is needed to reach half Vmax.
Question 9:
A Lineweaver-Burk plot is a:
A. Double reciprocal plot
B. Single reciprocal plot
C. Linear plot of rate vs. substrate
D. Logarithmic plot
Correct answer: A
Rationale: The Lineweaver-Burk plot graphs 1/V vs. 1/[S].
Question 10:
On a Lineweaver-Burk plot, the y-intercept represents:
A. 1/Vmax
B. Km
C. Vmax
D. Km/Vmax
Correct answer: A
Rationale: The y-intercept of the double reciprocal plot is 1/Vmax.
Question 11:
On a Lineweaver-Burk plot, the x-intercept represents:
A. −1/Km
B. 1/Km
C. Km
D. Vmax
Correct answer: A
Rationale: The x-intercept is −1/Km.
