Final answer:
The rate-limiting step in the manufacture of glycine is the transamination of serine.
Step-by-step explanation:
The rate-limiting step in the manufacture of glycine is the transamination of serine. Serine is the immediate precursor to glycine, which is formed by serine hydroxymethyltransferase. This enzyme requires the coenzyme tetrahydrofolate (THF), which is a derivative of vitamin B.