Fatty acid

One of many molecules that are long chains of lipid-carboxylic acid found in fats and oils and in cell membranes as a component of phospholipids and glycolipids. (Carboxylic acid is an organic acid containing the functional group -COOH.) Fatty acids come from animal and vegetable fats and oils. Fatty acids play roles outside the body; they are used as lubricants, in cooking and food engineering, and in the production of soaps, detergents, and cosmetics. Related terms include the following: Essential fatty acid: An essential fatty acid is a polyunsaturated fatty acid needed by the body that is synthesized by plants but not by the human body and is therefore a dietary requirement. Free fatty acids: By-products of the metabolism of fat in adipose tissues. Omega-3 fatty acids: Omega-3 fatty acids are a class of fatty acids found in fish oils, especially in salmon and other cold-water fish, that lowers the levels of cholesterol and LDL (low-density lipoproteins) in the blood. (LDL cholesterol is the "bad" cholesterol.) Trans fatty acid:Trans fatty acids (trans fats) are made through hydrogenation to solidify liquid oils. They increase the shelf life of oils and are found in vegetable shortenings and in some margarines, crackers, cookies, and snack foods. Intake of trans fatty acids increases blood LDL-cholesterol ("bad" cholesterol) levels and raises the risk of coronary heart disease..

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Any acid derived from fats by hydrolysis ( e.g., oleic, palmitic, or stearic acid s); any long-chain monobasic organic acid; they accumulate in disorders associated with the peroxisomes.

- activated f. a fatty acyl-coenzyme A thiol ester.

- diethenoid f. a f. containing two double bonds, e.g., linoleic acid.

- essential f. a f. that is nutritionally essential; E.G., linoleic acid, linolenic acid.

- ω-3 fatty acid s a class of fatty acid s that have a double bond three carbons from the methyl moiety; reportedly, they play a role in lowering cholesterol and LDL levels. SYN: omega-3 fatty acid s.

- omega-3 fatty acid s SYN: ω-3 fatty acid s.

- saturated f. a f., the carbon chain of which contains no ethylenic or other unsaturated linkages between carbon atoms ( e.g., stearic acid and palmitic acid); called saturated because it is incapable of absorbing any more hydrogen.

- f. synthase complex the multienzyme complex that catalyzes the formation of palmitate from acetyl-coenzyme A, malonyl-coenzyme A, and NADPH.

- f. thiokinase 1. long-chain: long-chain f.–CoA ligase; 2. medium-chain: butyrate-CoA ligase.

- unesterified free f. (FFA, UFA) free fatty acid s which occur in plasma as a result of lipolysis in adipose tissue or when plasma triacylglycerols are taken into tissues.

- unsaturated f. a f., the carbon chain of which possesses one or more double or triple bonds ( e.g., oleic acid, with one double bond in the molecule, and linoleic acid, with two); called unsaturated because it is capable of absorbing additional hydrogen.

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fatty acid n

1) any of numerous saturated aliphatic acids C_nH_2n+1COOH (as lauric acid) containing a single carboxyl group and including many that occur naturally usu. in the form of esters in fats, waxes, and essential oils

2) any of the saturated or unsaturated organic acids (as palmitic acid) that have a single carboxyl group and usu. an even number of carbon atoms and that occur naturally in the form of glycerides in fats and fatty oils

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an organic acid with a long straight hydrocarbon chain and an even number of carbon atoms. Fatty acids are the fundamental constituents of many important lipids, including triglyceride. Some fatty acids can be synthesized by the body; others, the essential fatty acid, must be obtained from the diet. Examples of fatty acids are palmitic acid, oleic acid, and stearic acid. See also fat.

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see under F.