ABSTRACT
Fatty acids have a long hydrocarbon chain with a terminal carboxylic acid group. Most fatty acids have an even number of carbon atoms in an unbranched chain. Saturated fatty acids have no double bonds between the carbon atoms, whereas mono- and polyunsaturated fatty acids have one or more double bonds. The properties of a fatty acid depend on the chain length and the number of double bonds. Shorter chain length fatty acids have lower melting temperatures than those with longer chains. Fatty acids are named according to the total number of carbon atoms, and to the number and position of any double bonds. The systematic names for fatty acids are made by adding 'oic acid' on to the name of the parent hydrocarbon. Fatty acids have several major biological roles: They are components of membranes and they act as energy stores and fuel molecules.
