The subunits of lipids are fatty acids and a connecting center. Triglyceride lipids, for example, consist of three fatty acids linked together with a glycerol ester.
Triglycerides, or fats, are the most widely known types of lipids and are distinguished by how their fatty acids are bonded. Saturated fat contains long chains of single-bonded fatty acids, monounsaturated fats contain a double bond and polyunsaturated fats contain more than one double bond.
Other lipids are built around chemicals other than glycerol. Cholesterol contains fatty acids linked through sterol, glycerophospholipids found in the brain use a phosphorous atom to link an amine and fatty acids and saccharolipids consist of fatty acids linked to a sugar.