fatty acid

one of a group of organic compounds, each consisting of a long, straight hydrocarbon chain and terminal carboxylic acid (COOH) group. The length of the chain varies from one to nearly 30 carbon atoms, and the chains may be saturated or unsaturated. Some fatty acids can be synthesized within the body, but others, the ESSENTIAL FATTY ACIDS , must be obtained from food. Fatty acids have three major roles within the body. 1. They are components of glycolipids (lipids containing carbohydrate) and phospholipids (lipids containing phosphate). These are of major importance in the structure of tissues and organs. 2. Fatty acids are important constituents of triglycerides (lipids that have three fatty acid molecules joined to a glycerol molecule). They are stored in the CYTOPLASM of many cells and are broken down when required to yield energy. They are the form in which the body stores fat. 3. Derivatives of fatty acids function as hormones and intracellular messengers.