Amino acid metabolism-Serine
synthesis of serine
- glycine (by reversal of serine hydroxymethyl transferase)
- glycolytic intermediate (3-phosphoglycerate)
- 3-phosphoglycerate → 3-phosphoglycerate dehydrogenase → 3-phosphohydroxypyruvate → (aminotransferse)(==PLP==) 3-phosphoserine → phosphoserine phosphatase → serine
Catabolism of serine
- conversion to glycine, then cleaved to CO2 & NH3
- pyruvate (by serine 2 dehydratase reaction) (non-oxidative deamination)
Functions and derivatives
- pyruvate (acid)
- carbon skeleton of cysteine
- forms glycine
- synth. of ceramide
- synth. ethanolamine (by 5-decarboxylation) = choline
- essential for synthesis of phospholipids (a lipotropic factor)
- source for one carbon moiety to ==THF== (by hydroxymethyl transferase reaction)
- OH site of covalent modification of enzyme activity
- glycogen synthase
- glycogen phosphorylase
- hormone sensitive lipase