WGU C785 BIOCHEMISTRY FINAL
EXAM PRACTICE QUESTIONS AND
ANSWERS
1. A patient presents with a defect in the enzyme that converts pyruvate to oxaloacetate.
Which of the following pathways would be most directly inhibited?
A. Glycolysis
B. Fatty acid synthesis
C. Gluconeogenesis
D. Ketogenesis
Answer: C
Conceptual Explanation: Pyruvate carboxylase converts pyruvate to oxaloacetate, a
critical first step in gluconeogenesis that bypasses the irreversible step of glycolysis.
2. Which of the following amino acids would most likely be found in the interior of a globular
protein?
A. Lysine
B. Phenylalanine
C. Glutamate
,D. Serine
Answer: B
Conceptual Explanation: Phenylalanine is a non-polar, hydrophobic amino acid that
sequester away from water into the protein core.
3. Under conditions of low blood glucose, which hormone initiates a signaling cascade that
results in the phosphorylation of glycogen phosphorylase?
A. Insulin
B. Cortisol
C. Glucagon
D. Testosterone
Answer: C
Conceptual Explanation: Glucagon signals the need for glucose by activating PKA, which
phosphorylates and activates glycogen phosphorylase to break down glycogen.
4. In the Electron Transport Chain, which complex is responsible for the reduction of oxygen
to water?
A. Complex I
B. Complex II
C. Complex III
D. Complex IV
, Answer: D
Conceptual Explanation: Complex IV (Cytochrome c oxidase) transfers electrons to
oxygen, the final electron acceptor, to form water.
5. Which type of mutation results in the replacement of a single amino acid with another
amino acid?
A. Silent mutation
B. Missense mutation
C. Nonsense mutation
D. Frameshift mutation
Answer: B
Conceptual Explanation: A missense mutation changes one codon so that it codes for a
different amino acid.
6. The secondary structure of a protein, such as an alpha-helix, is primarily stabilized by which
type of interaction?
A. Hydrogen bonds
B. Disulfide bonds
C. Ionic bonds
D. Hydrophobic interactions
Answer: A
EXAM PRACTICE QUESTIONS AND
ANSWERS
1. A patient presents with a defect in the enzyme that converts pyruvate to oxaloacetate.
Which of the following pathways would be most directly inhibited?
A. Glycolysis
B. Fatty acid synthesis
C. Gluconeogenesis
D. Ketogenesis
Answer: C
Conceptual Explanation: Pyruvate carboxylase converts pyruvate to oxaloacetate, a
critical first step in gluconeogenesis that bypasses the irreversible step of glycolysis.
2. Which of the following amino acids would most likely be found in the interior of a globular
protein?
A. Lysine
B. Phenylalanine
C. Glutamate
,D. Serine
Answer: B
Conceptual Explanation: Phenylalanine is a non-polar, hydrophobic amino acid that
sequester away from water into the protein core.
3. Under conditions of low blood glucose, which hormone initiates a signaling cascade that
results in the phosphorylation of glycogen phosphorylase?
A. Insulin
B. Cortisol
C. Glucagon
D. Testosterone
Answer: C
Conceptual Explanation: Glucagon signals the need for glucose by activating PKA, which
phosphorylates and activates glycogen phosphorylase to break down glycogen.
4. In the Electron Transport Chain, which complex is responsible for the reduction of oxygen
to water?
A. Complex I
B. Complex II
C. Complex III
D. Complex IV
, Answer: D
Conceptual Explanation: Complex IV (Cytochrome c oxidase) transfers electrons to
oxygen, the final electron acceptor, to form water.
5. Which type of mutation results in the replacement of a single amino acid with another
amino acid?
A. Silent mutation
B. Missense mutation
C. Nonsense mutation
D. Frameshift mutation
Answer: B
Conceptual Explanation: A missense mutation changes one codon so that it codes for a
different amino acid.
6. The secondary structure of a protein, such as an alpha-helix, is primarily stabilized by which
type of interaction?
A. Hydrogen bonds
B. Disulfide bonds
C. Ionic bonds
D. Hydrophobic interactions
Answer: A
