WGU C785 BIOCHEMISTRY FINAL
EXAM 2026 QUESTIONS AND ANSWERS
1. Which of the following amino acids is most likely to be found in the interior of a globular
protein in an aqueous environment?
A. Phenylalanine
B. Lysine
C. Aspartate
D. Serine
Answer: A
Conceptual Explanation: Hydrophobic amino acids like Phenylalanine are driven into the
protein interior to avoid contact with water, minimizing the surface area of hydrophobic
contact.
2. A patient presents with a high HbA1c level of 9.0%. Which biochemical process explains
why glucose attaches to hemoglobin?
A. Enzymatic glycation
B. Acetylation
,C. Phosphorylation
D. Non-enzymatic glycation
Answer: D
Conceptual Explanation: HbA1c forms through a non-enzymatic reaction between
glucose and the N-terminal valine of the hemoglobin beta chain.
3. In the Lineweaver-Burk plot, a competitive inhibitor will cause which change to the kinetic
parameters?
A. No change in Vmax and increased Km
B. Increased Vmax and decreased Km
C. Decreased Vmax and no change in Km
D. Decreased Vmax and decreased Km
Answer: A
Conceptual Explanation: Competitive inhibitors compete for the active site, increasing the
apparent Km (lowering affinity) while Vmax remains reachable at high substrate
concentrations.
4. Which enzyme in glycolysis catalyzes the first ‘committed step’ that is heavily regulated?
A. Hexokinase
B. Pyruvate Kinase
C. Aldolase
, D. Phosphofructokinase-1 (PFK-1)
Answer: D
Conceptual Explanation: PFK-1 catalyzes the conversion of Fructose-6-phosphate to
Fructose-1,6-bisphosphate and is the primary rate-limiting step of glycolysis.
5. A deficiency in which vitamin would directly impair the function of Pyruvate
Dehydrogenase Complex?
A. Vitamin C
B. Vitamin B12
C. Thiamine (B1)
D. Vitamin A
Answer: C
Conceptual Explanation: Thiamine pyrophosphate (TPP) is a critical cofactor for the E1
subunit of the Pyruvate Dehydrogenase Complex.
6. What is the primary role of the Bohr effect in hemoglobin function?
A. To increase oxygen affinity in the lungs
B. To decrease oxygen affinity in tissues with low pH
C. To prevent CO2 from binding to hemoglobin
D. To stabilize the R-state of hemoglobin
EXAM 2026 QUESTIONS AND ANSWERS
1. Which of the following amino acids is most likely to be found in the interior of a globular
protein in an aqueous environment?
A. Phenylalanine
B. Lysine
C. Aspartate
D. Serine
Answer: A
Conceptual Explanation: Hydrophobic amino acids like Phenylalanine are driven into the
protein interior to avoid contact with water, minimizing the surface area of hydrophobic
contact.
2. A patient presents with a high HbA1c level of 9.0%. Which biochemical process explains
why glucose attaches to hemoglobin?
A. Enzymatic glycation
B. Acetylation
,C. Phosphorylation
D. Non-enzymatic glycation
Answer: D
Conceptual Explanation: HbA1c forms through a non-enzymatic reaction between
glucose and the N-terminal valine of the hemoglobin beta chain.
3. In the Lineweaver-Burk plot, a competitive inhibitor will cause which change to the kinetic
parameters?
A. No change in Vmax and increased Km
B. Increased Vmax and decreased Km
C. Decreased Vmax and no change in Km
D. Decreased Vmax and decreased Km
Answer: A
Conceptual Explanation: Competitive inhibitors compete for the active site, increasing the
apparent Km (lowering affinity) while Vmax remains reachable at high substrate
concentrations.
4. Which enzyme in glycolysis catalyzes the first ‘committed step’ that is heavily regulated?
A. Hexokinase
B. Pyruvate Kinase
C. Aldolase
, D. Phosphofructokinase-1 (PFK-1)
Answer: D
Conceptual Explanation: PFK-1 catalyzes the conversion of Fructose-6-phosphate to
Fructose-1,6-bisphosphate and is the primary rate-limiting step of glycolysis.
5. A deficiency in which vitamin would directly impair the function of Pyruvate
Dehydrogenase Complex?
A. Vitamin C
B. Vitamin B12
C. Thiamine (B1)
D. Vitamin A
Answer: C
Conceptual Explanation: Thiamine pyrophosphate (TPP) is a critical cofactor for the E1
subunit of the Pyruvate Dehydrogenase Complex.
6. What is the primary role of the Bohr effect in hemoglobin function?
A. To increase oxygen affinity in the lungs
B. To decrease oxygen affinity in tissues with low pH
C. To prevent CO2 from binding to hemoglobin
D. To stabilize the R-state of hemoglobin
