Fatty acids are made up largely of a chain of carbon atoms bonded with hydrogen atoms. The chain is made up of two terminals, the carboxyl terminal and the hydroxyl terminal. The carboxyl terminal consist of a carboxyl group which is the reactive portion of the molecule which participate in chemical reactions while the hdyroxy terminal of the chain consists of the OH group. The number of carbon and hydrogen atoms in a fatty acid depend on the type of fatty acid it is. Fatty acids can be saturated or unsaturated and this determines whether they have single or double bonds and the number of bonds that they possess.