Biochemistry Multiple Choice Questions on “Pathways of Amino Acid Degradation”.
1. Which of the following amino acids are exclusively ketogenic?
A. Leucine
B. Asparagine
C. Threonine
D. Proline
Answer: A
Clarification: Only two amino acids, leucine and lysine are exclusively ketogenic.
2. Which of the following are exclusively glucogenic?
A. Arginine
B. Leucine
C. Lysine
D. Threonine
Answer: A
Clarification: Leucine and lysine are exclusively ketogenic. Threonine is both ketogenic and glucogenic.
3. Which of the following yields acetyl co-A via aceto-acetyl co-A?
A. Leucine
B. Isoleucine
C. Threonine
D. Alanine
Answer: A
Clarification: Leucine, lysine, phenylalanine and tryptophan yield acetyl co-A via aceto-acetyl co-A.
4. Which of the following yields acetyl coA directly?
A. Phenylalanine
B. Isoleucine
C. Lysine
D. Alanine
Answer: B
Clarification: Isoleucine, leucine, threonine and tryptophan yield acetyl coA directly.
5. Which of the following produces pyruvate?
A. Leucine
B. Isoleucine
C. Lysine
D. Alanine
Answer: D
Clarification: The amino acids producing pyruvate are alanine, cysteine, glycine, serine, threonine and tryptophan.
6. Which of the following produces α-ketoglutarate?
A. Leucine
B. Threonine
C. Methionine
D. Proline
Answer: D
Clarification: Arginine, glutamate, glutamine, histidine and proline produce α-ketoglutarate.
7. Which of the following produce succinyl co-A?
A. Leucine
B. Isoleucine
C. Arginine
D. Alanine
Answer: B
Clarification: Isoleucine, methionine, threonine and valine produce succinyl co-A.
8. Fumarate is produced from four carbon atoms of _________
A. Tyrosine
B. Isoleucine
C. Threonine
D. Alanine
Answer: A
Clarification: Four carbon atoms of phenylalanine and tyrosine give rise to fumarate.
9. Which of the following produces oxaloacetate?
A. Aspartate
B. Isoleucine
C. Threonine
D. Alanine
Answer: A
Clarification: Asparagine and aspartate produce oxaloacetate.
10. The branched chain amino acid is not _________
A. Leucine
B. Isoleucine
C. Valine
D. Alanine
Answer: D
Clarification: Isoleucine, leucine and valine are the branched chain amino acids.