Question

which b vitamin can be made from the amino acid tryptophan after protein synthesis needs have been met?
o a. biotin
o b. niacin
o c. thiamin
o d. riboflavin
check my work

Explanation:

To determine which B vitamin is synthesized from the amino acid tryptophan (after protein synthesis needs are met), we analyze each option:

• Option a (Biotin): Biotin is not synthesized from tryptophan. It is involved in carboxylation reactions and is obtained from dietary sources or synthesized by gut bacteria.
• Option b (Niacin): Niacin (vitamin B₃) can be synthesized in the body from the essential amino acid tryptophan, provided that the body's protein synthesis requirements for tryptophan are satisfied first.
• Option c (Thiamin): Thiamin (vitamin B₁) is not synthesized from tryptophan. It is obtained from dietary sources and is crucial for energy metabolism.
• Option d (Riboflavin): Riboflavin (vitamin B₂) is not synthesized from tryptophan. It is obtained from food and is involved in redox reactions.

Answer:

b. Niacin