fatty acid biosynthetic pathway Acetyl-CoA, the starting material for fatty acid biosynthesis, can be derived from amino acid and lipid degradation or the oxidative decarboxylation of pyruvate. Fatty acid biosynthesis involves the condensation of C2 units; it requires seven enzymatic reactions which are carried out by the multifunctional enzyme fatty acid synthase. PW:0000029 PW:0000030 fatty acid biosynthetic process pathway fatty acid metabolic pathway