Fats, also called lipids, are composed of the elements carbon, hydrogen and oxygen. Three fatty acid chains attach to one glycerol unit to form a triglyceride, the most common form of dietary fat.
Fats are the most prevalent type of compound found in living organisms. Fats are composed of triglycerides, which consist of three fatty acid chains and one glycerol unit. A glycerol unit is a molecule with a hydroxyl functional group attached to each of its three carbons. Fatty acids are long carbon-hydrogen chains that contain a carboxylic acid functional group at the end. Fatty acids can be either saturated, lacking carbon-carbon double bonds, or unsaturated, containing carbon-carbon double bonds.