Chemistry of Life

Molecular genetics, biochemistry


Phospholipids are formed from four components: fatty acids, a negatively charged phosphate group, an alcohol and a backbone. Phospholipids with a glycerol backbone are known as glycerophospholipids or phosphoglycerides. (left - click to enlarge image)

Essential fatty acids are required in the diet because, lacking the necessary desaturase enzymes, humans are unable to biosynthesize omega fatty acids, though we do possess the bio-machinery for their interconversion. The two closely related families of EFAs are : omega-3 (ω-3, or n-3) α-linolenic acid (18:3), and omega-6 (ω-6, n-6) linoleic acid (18:2). The EFAs serve as substrates for the biosynthesis of longer, more desaturated fatty acids (long-chain polyunsaturates).

Only sphingomyelin has a sphingosine backbone. Sphingomyelin is present in all eukaryotic cell membranes, but is mainly present in cells of the nervous system. Phospholipids, along with glycolipids and cholesterol, are a major component of all biological membranes.


. . . transcription begun 10/06/06