The biosynthesis of serine begins with 3-phospho-D-glycerate being metabolize into 3-phosphohydroxypyruvate through a 3-phosphoglycerate dehydrogenase. The resulting compound 3-phosphohydroxypyruvate is transaminated into 3-phospho-L-serine through a phosphoserine transaminase. This is followed by 3-phospho-L-serine being dephosphorylated through a phosphoserine phosphatase resulting in the release of a phosphate and Serine. Serine can also be incorporated into the mitochondrion and then serine can then be used to synthesize glycine through a mitochondrial serine hydroxymethyltransferase. Glycine is then used to synthesize formic acid by first being metabolized into 5,10 methylene THF, which is transformed into a 5,10 methenyltetrahydrofolate , followed by an N10 formyl tetrahydrofolate and lastly formic acid, all through a mitochondrial C1-tetrahydrofolate synthase. In the cytosol serine can either be degraded to synthesize glycine through a serine hydroxymethyltransferase or it can be degraded into 2-aminoprop-2-enoate. The latter compound can be spontaneously be converted first into 2-iminopropanoate and this compound is then converted into pyruvic acid.

Serine Metabolism References