Phosphatidic acid is a phospholipid and an intermediate in glycerolipid biosynthesis. It is a transient intermediate in the synthesis of various phospholipid species that is synthesized de novo in cells via multiple routes, including the glycerol-3 phosphate and dihydroxyacetone phosphate pathways, enzymatic conversion of phosphatidylcholine by phospholipase D, and acetylation of lysophosphatidic acid by lysoPA-acyltransferase, among others. It has roles in shaping cellular membranes, cellular signaling, vesicle fission and fusion, as well as mitochondrial division and fusion. It stimulates respiratory burst in neutrophils independent of diacylglycerol and activates monoacylglycerol acyltransferase, phospholipase C (PLC), Ras, and phosphatidylinositol 4-phosphate (PIP4) kinase in several cell lines. Phosphatidic acids (egg) is a mixture of phosphatidic acids isolated from chicken egg with fatty acids of variable chain lengths.