Sphingolipids have a polar head and two nonpolar tails, but unlike glycerophospholipids they contain no glycerol. Sphingolipids are composed of one molecule not the long chain amino alcohol sphingosine (4-sphingenine) or one of its derivatives, one molecule of a long chain fatty acid, a polar head alcohol, and sometimes phosphoric acid in diester linkage at the polar head group. When a fatty acid is attached in amide linkage to the –NH2, the resulting compound is a ceramide, which is structurally similar to diacylglycerol. Ceramide is the fundamental structural unit common to all sphingolipids

The scheme above shows sphingosine in red and the fatty acid in blue. The green X is an example of any sphingolipid take into consideration.

There are three subclasses of sphingolipids, all derivatives of ceramide, but differing in their head groups: sphingomyelins, neutral (uncharged) glycolipids, cerebrosides and gangliosides.

Sphingomyelins contain phosphocoline or phosphoethanolamine as their polar head group. Cerebrosides have a singular sugar linked to ceramide and gangliosides, the most complex sphingolipids, contain a very large polar heads made up of several sugar units. Gangliosides make up about 6% of the membrane lipids in the gray matter of the human brain, and they are present in lesser amounts in the membranes of most nonneural animal tissues.