1. Lipid Synthesis Prof S. Kajuna
Triacylglycerols
Synthesis of triacylglycerols occurs primarily in
liver and in adipose tissue from CoA derivative of fatty
acids via phosphatidic acid.
Free fatty acids are converted to acyl CoA derivatives by one of several chain-length dependent fatty acid CoA ligases in microsomes.

2. Fatty acid + CoA + ATP = Fatty acyl CoA + AMP +ppi
1-acylglycerol -3-phosphate is then formed from acyl CoA and L-glycerol-3-phosphate to give 1-acylglycerol-3-phosphate in a reaction catalysed by glycerol-3-phosphate acyltransferase. 1-acylglycerol-3-phosphate reacts with a second acyl CoA in a reaction catalysed by lysophosphatidic acid acyltransferase to give phosphatidic acid.

3. Phosphatidic acid is a precursor of both the triacylglycerols and some phosphoglycerides.
Glycerol-3-phosphate is derived from free glycerol which is phosphorylated by glycerokinase and ATP, or by reduction of dihydroxyacetone phosphate.
Hydrolysis of phosphatidic acid by a phosphatidic acid phosphatase yields a 1,2-diacylglycerol, which in turn reacts with another mole of acyl CoA in a reaction catalysed by diacylglycerol acyltransferase to form a neutral triacylglycerol.

4. In addition to the above pathway for formation of phosphatidic acid, there is acylation of dihydroxyacetone phosphate by dihydroxyacetone phosphate acyltransferase.
Reduction to lysophosphatidic acid is accomplished by a microsomal oxidoreductase.