12 COOH Often found attached to the N-term. Basic composition of a triacylglyceride. The glycerol backbone is in blue. The building block of the phospholipids is phosphatidic acid which results when the X substitution in the basic structure shown in the Figure below is a hydrogen atom. Basic composition of a phospholipid.
X can be a number of different substituents.
A basic O -alkenyl ether species is shown in the Figure below. Sphingosine is N-acetylated by a variety of fatty acids generating a family of molecules referred to as ceramides . Sphingolipids predominate in the myelin sheath of nerve fibers. Sphingomyelin is an abundant sphingolipid generated by transfer of the phosphocholine moiety of phosphatidylcholine to a ceramide, thus sphingomyelin is a unique form of a phospholipid. Sphingosine the atoms in red are derived from glycerol.