What are the building blocks of a phosphoglyceride,specifically phosphatidic acid?

Glycerol + 1 phosphate group +2 fatty acids. Phosphatidic acids are phospholipids which during hydrolysis increases to one molecule each of glycerol and phosphoric acid and two molecules of fatty acids. They constitute about one-quarter of phospholipids in the bilayer. The role of PA in the cell is that it is the precursor for the biosynthesis of many other lipids.

PA acts a signaling lipid, recruiting cytosis proteins to appropriate membranes. Phosphatidic acid is inclusive of a glycerol backbone, with, in general, a saturated fatty acid bonded, with, in general, carbon -1, an unsaturated fatty bonded to carbon-2 and a phosphate group bonded to carbon -3. PA is a unique phospholipid in that it has a small highly changed head group that it is very close to the glycerol backbone.