phospholipid metabolism phosphatidylcholine biosynthesis 1,2-diacyl-sn-glycero-3-phosphocholine biosynthesis UPa:UPA00753 pathway lecithin biosynthesis GO:0006656 Biosynthesis of phosphatidylcholine, also called lecithin, a class of phospholipids in which the phosphatidyl group is esterified to the hydroxyl group of choline. Phosphatidylcholine is the most-abundant phospholipid found in eukaryotic membranes. Additionally to its structural function in membrane bilayers and lipoproteins, phosphatidylcholine is involved in many signal transduction pathways. Phosphatidylcholine has also been found in an increasing number of bacteria, in particular in species that interact with eukaryotic hosts. PMID:18978052 PMID:14663079 KEGG:map01100 KEGG:map00564 glycerophospholipid biosynthesis