Lipids are organic compounds that can include substances, such as fats, waxes, phospholipids and steroids. Depending on the type of lipid formed, it can consist of different combinations of molecules including fatty acids, glycerol and phosphate group. Triglycerides, which are a type of fat, are made up of three fatty acids and one glycerol molecule, while phospholipids consist of two fatty acids, one glycerol molecule and a phosphate group.
Steroids are different in composition than either fats or phospholipids because this class of lipid consists of four connected carbon rings. Other chemical groupings can be attached to these rings, depending on the specific steroid being formed. Cholesterol and cortisol are two different types of steroids. Waxes are esters made up of a fatty acid and a long-chain alcohol.
Fatty acids are composed of a carboxyl group linked with a hydrocarbon chain that can be long. They consists of the elements carbon, hydrogen and oxygen. Lipids are macromolecules that are insoluble in water.