Fatty acyl-CoAs and glycerol-3-phosphate are the primary precursors to triacylglycerols. Glycerol-3-phosphate can be made by

1. Reduction of dihydroxyacetone phosphate (catalyzed in adipocytes by glycerol phosphate dehydrogenase)

2. ATP-dependent phosphorylation of glycerol by glycerol kinase

Adiopocytes do not contain glycerol kinase and thus cannot rebuild a fat from glycerol generated by hydrolysis of another fat.

Glycerol-3-phosphate is joined to two fatty acyl groups to form diacylglycerol-3-phosphate, also known as phosphatidic acid, which is a precursor to phospholipids and triacylglycerols . Conversion to triacylglycerols involves hydrolysis of the phosphate group to form diacylglycerol followed by addition of a third acyl group from a fatty acyl-CoA.

See also: Triacylglycerols