Carbon Skeleton Fate MCQ Quiz | Amino Acid Metabolism

1. Which of the following amino acids is exclusively ketogenic?

2. The carbon skeleton of Alanine is converted to which metabolic intermediate?

3. A defect in the degradation of branched-chain amino acids leads to which condition?

4. Glutamate is converted to which TCA cycle intermediate via transamination or oxidative deamination?

5. Phenylalanine and Tyrosine are degraded to fumarate and what other ketogenic product?

6. Which two amino acids are converted to oxaloacetate, one via asparaginase and the other by a single transamination step?

7. The degradation of methionine, valine, and isoleucine generates which intermediate that enters the TCA cycle?

8. Which of the following is NOT a glucogenic amino acid?

9. The conversion of histidine to α-ketoglutarate requires the transfer of a formimino group to which coenzyme?

10. Tryptophan is a precursor for niacin synthesis and is catabolized to which two types of end products, making it both glucogenic and ketogenic?

11. Phenylketonuria (PKU) is caused by a deficiency in which enzyme?

12. The carbon skeletons of asparagine and aspartate enter the citric acid cycle as:

13. Propionyl-CoA, an intermediate in the degradation of several amino acids, is converted to Succinyl-CoA in a reaction requiring which vitamin?

14. Which amino acid is degraded to yield HMG-CoA, a precursor for both ketone bodies and cholesterol?

15. The “one-carbon” pool, involving tetrahydrofolate, is crucial for the interconversion and metabolism of which of the following amino acids?

16. The catabolism of arginine and proline ultimately yields which TCA cycle intermediate?

17. Which amino acid’s carbon skeleton directly enters the TCA cycle as fumarate?

18. The transamination reaction, a key first step in amino acid catabolism, universally requires which coenzyme?

19. Which of the following amino acids can be synthesized from pyruvate in a single transamination step?

20. Alkaptonuria, characterized by dark urine upon standing, results from a deficiency in the enzyme that metabolizes:

21. The carbon atoms of Glycine can enter metabolic pathways as all of the following EXCEPT:

22. The catabolism of threonine produces both acetyl-CoA and glycine. This classifies threonine as:

23. The family of amino acids catabolized to α-ketoglutarate includes Glutamate, Glutamine, Proline, Arginine, and:

24. A patient is diagnosed with Maple Syrup Urine Disease (MSUD). The degradation of which of these amino acids is NOT impaired?

25. The final product of lysine degradation is: