This is caused by the biosynthesis of fatty acids where C 2 -unities are combined to chains. Among the unsaturated fatty acids are compounds with one, two or three double bonds.
Triglycerides make up the chief amount of storage fats.
Lipids with short fatty acid residues take part in the species-specific flavour of several fruits. The esters of fatty acids with long-chained alcohols are called waxes . Phospholipids are counted among the complex lipids. They are essential structural elements of membranes . They have two fatty acids residues linked to glycerol.