A fatty acid consists of the elements carbon (C), hydrogen (H) and oxygen (O) arranged as a carbon chain skeleton with a carboxyl group (-COOH) at one end. Fatty acids can be “saturated” and “unsaturated”. Saturated fatty acids have all the hydrogen that the carbon atoms can hold; they are saturated with hydrogen atoms. Unsaturated fatty acids are not saturated with hydrogen, and therefore, have double bonds (=) between the carbons atoms. While “monounsaturated fatty acids” have only one double bond, “polyunsaturated fatty acids” have more than one double bond. Fatty acids are frequently represented by a notation such as “C18:2”, which indicates that the fatty acid consists of an 18-carbon chain and 2 double bonds.