Question

Which one of the following coenzymes is required for the conversion of L-alanine to a racemic mixture of D- and L-alanine?

• A. Pyridoxal-$6$-phosphate
• B. Thiamine pyrophosphate
• C. Coenzyme A
• D. Flavin adenine dinucleotide

Answer 1

Answer: (A)

Pyridoxal-$6$-phosphate

Pyridoxal-6-phosphate is the active form of vitamin B${}_6$. It acts as coenzyme in many enzymatic reactions. One of the reaction in which it functions as coenzymes is the conversion of L-alanine to a recemic mixture of D- and L-alanine. This reaction is catalyzed by enzyme alanine racemase.

Thus, the correct answer is option A.