TABLE 1.

Classes of lipids.

Categories	Composition	Function	Classes or examples
Fatty acids	Carboxylic acid + hydrocarbon chain; synthesized by chain elongation of an acetyl-CoA with malonyl-CoA	Building blocks to complex lipids	SFA, MUFA, PUFA
Glycerolipids	FA + glycerol; may have sugar residues	Energy storage, cell signaling	TAG, DAG, MAG
Glycerophospholipids	Polar head group + glycerol group, may contain LCFA	Membrane composition, cell signaling	PC, PE, PS, PI, PA
Sphingolipids	Sphingoid base + LCFA-CoA	Membrane and lipoprotein composition, cell signaling	Ceramides, Phosphosphingolipids, glycosphingolipids
Sterols	Hydroxyl group + steroid	Membrane, precursor to hormones and vitamins	Cholesterol, bile acids
Prenols	Isopentenyl diphosphate + dimethylallyl diphosphate	Antioxidants, vitamin precursor	Quinone, ubiquinone, Vitamin E, Vitamin K
Saccharolipids	FAs + sugar backbone	Membrane components	Glucosamine
Polyketides	Acetyl + propionyl polymerization	Secondary metabolites	Tetracycline, erythromycin

List of the different categories of lipids, as defined by the LIPID MAPS consortium, with summaries of their average composition, functions and classes. FA, fatty acid; SFA, short chain fatty acid; MUFA, mono-unsaturated fatty acid; PUFA, poly-unsaturated fatty acid; TAG, triacylglycerol; DAG, diacylglycerol; MAG, monoacylglycerol; PC, phospatidylcholine; PE, phosphatidylethanolamine; PS, phosphatidylserine; PI, phosphatiylinositol; PA, phosphatidic acid; LCFA-CoA, long-chain fatty acid-coenzyme A.