How Are Lipids Classified?

Lipids are classified into four types, namely simple lipids, compound lipids, terpenoids and steroids and derived lipids. Simple lipids are subdivided into triglycerides or neutral fats (found in adipose tissue, butterfat, lard, suet, fish oils, olive oil, corn oil, etc.) and waxes (found in beeswax, head oil of the sperm whale, cerumen, carnauba oil and lanolin.)

Compound lipids are subdivided into phospholipids (or phoshatides), lecithin, cephalin, plasmalogen, lopisitol, sphingomyelin and glycolipids. Glycolipids are further subdivided into cerebroside, ganglioside, sulfolipid and proteolipids.

Terpenoids and steroids are subdivided into terpenes, sterols (cholesterol, ergosterol and 7-dehydrocholesterol), androgens and estrogens and adrenal corticolsteroids. Derived lipids are also known as fatty acids, which mainly occur either in plant or animal foods, and are also found in complex forms combined with other substances.

Fatty acids are classified on the bases of the length of carbon and the number of double bonds. The various types of fatty acids are butyric acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid.