This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Serine is produced in human from - 
Select and explain. 
A. Glycine, B. Methionine, C. Homocysteine, D. Homoserine
A: Glycine
Answer: A: Glycine 
Explanation: Ans. is 'a' i.e., GlycineSerine is conveed to glycine and after that its metabolism is similar to glycine. Conversion of serine to glycine is reversible reaction; therefore, serine is synthesized also from glycine.