A long-chain carboxylic acid that contains one or more C=C double bonds. See saturated fatty acid.
A fatty acid possessing one or more double bonds between the carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton.
A fatty acid that lacks hydrogen atoms and has at least one double bond between carbons. Includes monounsaturated and polyunsaturated fatty acids. An unsaturated fat is composed of triglycerides in which most of the fatty acids are unsaturated.