Major source of one carbon fragment in human metabolism | PGI Nov 2017 Preparations MCQ

All of the following amino acids is/are the major source of one carbon fragment in human metabolism except?

A. Alanine 
B. Glutamate 
C. Aspartate 
D. Serine
E. Taurine

Answer. A. Alanine ; (B) Glutamate; (C) Aspartate; (E) Taurine

Serine reacts with tetrahydrofolate to form N5, N10 -methylenetetrahydrofolate, water, and glycine. Serine is the major source of one-carbon fragments in mammalian metabolism.