Introduction:
D-Serine, synthesized in the brain by serine racemase from L- serine (its enantiomer), serves as both a neurotransmitter and a gli otransmitter by activating NMDA receptors, making them able to op en if they then also bind glutamate.serine is a more potent agonist at the glycine site on the NMDAR than glycine itself.

Function:
Serine is important in metabolism in that it participates in the biosynthesis of purines and pyrimidines. It is the precursor to several amino acids including glycine and cysteine, and tryptophan in bacteria. It is also the precursor to numerous of other metabolites, including sphingolipids and folate, which is the principal donor of one-carbon fragments in biosynthesis. Serine dehydratase is an enzyme that converts serine to pyruvate.