What are phospholipids?

Phospholipids are molecules made of glycerol bound to two long molecules of fatty acids and to one phosphate group. Thus, phospholipids are amphipathic molecules, i.e., they have a non-polar portion, because the long fatty acid chains, and a polar portion, because of the group phosphate.

Phospholipids are the main part of cell membranes. Sphingomyelin, the substance that forms the myelin sheath of axons in the nervous system, is a phospholipid too.

Lipids and Fat Review - Image Diversity: phospholipid molecule