Compound lipids differ from simple lipids in having an additional nonlipid portion.
Compound lipids usually consist of fatty acid, an alcohol and one or more other groups such as phosphorus or nitrogen. These can be formed in the brain and central nervous system.
Compound lipids are not fats, and their amount remains constant in the organisms.
The compound lipids are amphipathic molecules. They can be subclassified into the following categories.
*Phospholipids: contain an additional phosphate group
*Glycolipids: contain carbohydrate groups. This lipid is present in combination with a carbohydrate (galactose).
Lecithin, the best known among phospholipids in plant cells, is an essential structural material for living cell membrane, whether to maintain continuity between the water and lipid phases inside and outside the cells.
The functions of certain enzymes depend upon their attachments to lipids such as lecithin.
Classification of lipids: Compound lipids