fatty acids

fatty acids

A large group of monobasic acids found in animals and plants. They are hydrocarbon chains and are saturated or unsaturated aliphatic compounds with an even number of carbon atoms. Chain lengths range up to nearly 30 carbon atoms. Fatty acids with more than about 8 carbon atoms in the chain occur most commonly as constituents of glycerides, phospholipids and sterols. The most abundant fatty acids are palmitic, stearic and oleic acids. Glucose and fatty acids are the two main fuel substances of the body. FATS are glyceride esters of fatty acids.

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

fatty acids

a range of molecules with the general formula C_n H_2n+ 1COOH that occur naturally in many organisms, often combined with glycerol to form FATS. Fatty acids are of two main types: unsaturated, with at least one carbon-to-carbon double bond, and saturated, with no such bonds. The greater the proportion of unsaturated fatty acids in a fat the lower its melting point, with many unsaturated fats being liquid oils at room temperature. There is evidence that excess consumption of saturated fats can lead to hardening of the arteries (see ARTERIOSCLEROSIS), but the facts are disputed, particularly by butter manufacturers.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005