CHEM 210 BIOCHEMISTRY
COMPREHENSIVE EXAM QUESTIONS
AND ANSWERS 2026/2027 UPDATE ||
100% GUARANTEED PASS
1. Which of the following amino acids is most likely to be found in the interior of a globular
protein due to the hydrophobic effect?
A. Asparagine
B. Phenylalanine
C. Glutamate
D. Lysine
Answer: B
Conceptual Explanation: Phenylalanine has a non-polar aromatic side chain, making it
hydrophobic and likely to be buried away from the aqueous environment.
2. In the Michaelis-Menten equation, what does the constant Km represent?
A. The maximum velocity of the reaction
B. The turnover number of the enzyme
C. The substrate concentration at which the reaction velocity is half of Vmax
D. The equilibrium constant of the reaction
,Answer: C
Conceptual Explanation: Km, the Michaelis constant, is defined as the substrate
concentration at which the reaction rate is exactly half of the maximum velocity (Vmax).
3. Which molecule acts as a critical allosteric inhibitor of Phosphofructokinase-1 (PFK-1) in the
glycolytic pathway?
A. AMP
B. Fructose-2,6-bisphosphate
C. ATP
D. ADP
Answer: C
Conceptual Explanation: High levels of ATP signal that the cell has sufficient energy, thus
ATP binds to an allosteric site on PFK-1 to inhibit glycolysis.
4. The conversion of Pyruvate to Acetyl-CoA is catalyzed by which enzyme complex?
A. Pyruvate Dehydrogenase Complex
B. Pyruvate Kinase
C. Pyruvate Carboxylase
D. Lactate Dehydrogenase
Answer: A
, Conceptual Explanation: The Pyruvate Dehydrogenase Complex performs the oxidative
decarboxylation of pyruvate to acetyl-CoA, linking glycolysis to the TCA cycle.
5. Which of the following best describes the ‘Bohr Effect’ regarding hemoglobin?
A. Increased pH leads to lower oxygen affinity
B. Increased CO2 and H+ concentration leads to decreased oxygen affinity
C. 2,3-BPG increases oxygen affinity
D. Low partial pressure of oxygen promotes R-state stabilization
Answer: B
Conceptual Explanation: The Bohr Effect describes how hydrogen ions and carbon
dioxide stabilize the T-state (deoxyhemoglobin), causing a shift to the right in the oxygen
dissociation curve.
6. During DNA replication, which enzyme is responsible for unwinding the double helix at the
replication fork?
A. Helicase
B. DNA Polymerase III
C. DNA Ligase
D. Topoisomerase
Answer: A
COMPREHENSIVE EXAM QUESTIONS
AND ANSWERS 2026/2027 UPDATE ||
100% GUARANTEED PASS
1. Which of the following amino acids is most likely to be found in the interior of a globular
protein due to the hydrophobic effect?
A. Asparagine
B. Phenylalanine
C. Glutamate
D. Lysine
Answer: B
Conceptual Explanation: Phenylalanine has a non-polar aromatic side chain, making it
hydrophobic and likely to be buried away from the aqueous environment.
2. In the Michaelis-Menten equation, what does the constant Km represent?
A. The maximum velocity of the reaction
B. The turnover number of the enzyme
C. The substrate concentration at which the reaction velocity is half of Vmax
D. The equilibrium constant of the reaction
,Answer: C
Conceptual Explanation: Km, the Michaelis constant, is defined as the substrate
concentration at which the reaction rate is exactly half of the maximum velocity (Vmax).
3. Which molecule acts as a critical allosteric inhibitor of Phosphofructokinase-1 (PFK-1) in the
glycolytic pathway?
A. AMP
B. Fructose-2,6-bisphosphate
C. ATP
D. ADP
Answer: C
Conceptual Explanation: High levels of ATP signal that the cell has sufficient energy, thus
ATP binds to an allosteric site on PFK-1 to inhibit glycolysis.
4. The conversion of Pyruvate to Acetyl-CoA is catalyzed by which enzyme complex?
A. Pyruvate Dehydrogenase Complex
B. Pyruvate Kinase
C. Pyruvate Carboxylase
D. Lactate Dehydrogenase
Answer: A
, Conceptual Explanation: The Pyruvate Dehydrogenase Complex performs the oxidative
decarboxylation of pyruvate to acetyl-CoA, linking glycolysis to the TCA cycle.
5. Which of the following best describes the ‘Bohr Effect’ regarding hemoglobin?
A. Increased pH leads to lower oxygen affinity
B. Increased CO2 and H+ concentration leads to decreased oxygen affinity
C. 2,3-BPG increases oxygen affinity
D. Low partial pressure of oxygen promotes R-state stabilization
Answer: B
Conceptual Explanation: The Bohr Effect describes how hydrogen ions and carbon
dioxide stabilize the T-state (deoxyhemoglobin), causing a shift to the right in the oxygen
dissociation curve.
6. During DNA replication, which enzyme is responsible for unwinding the double helix at the
replication fork?
A. Helicase
B. DNA Polymerase III
C. DNA Ligase
D. Topoisomerase
Answer: A
