- Another word for "fat." (Please see the various meanings of Fat.) A lipid is more formally defined as a substance such as a fat, oil or wax that dissolves in alcohol but not in water. Lipids contain carbon, hydrogen and oxygen but have far less oxygen proportionally than carbohydrates. Lipids are an important part of living cells. Together with carbohydrates and proteins, lipids are the main constituents of plant and animal cells. Cholesterol and triglycerides are lipids. Lipids are easily stored in the body. They serve as a source of fuel and are an important constituent of the structure of cells. Lipids include fatty acids, neutral fats, waxes and steroids (like cortisone). Compound lipids (lipids complexed with another type of chemical compound) comprise the lipoproteins, glycolipids and phospholipids. Etymology: Whereas the everyday term "fat" comes from the Old English (from "faett" meaning crammed or adorned), the more scientific term "lipid" comes from the Greek "lipos" which referred to animal fat or vegetable oil. The derivation of a biomedical term from another tongue such as Greek, Latin or French lends it a certain "je ne sais quoi" (something that cannot be easily expressed), a touch of continental class.
* * *“Fat-soluble,” an operational term describing a solubility characteristic, not a chemical substance, i.e., denoting substances extracted from animal or vegetable cells by nonpolar solvents; included in the heterogeneous collection of materials thus extractable are fatty acid s, glycerides and glyceryl ethers, phospholipids, sphingolipids, long-chain alcohols and waxes, terpenes, steroids, and “fat-soluble” vitamins such as A, D, and E. [G. lipos, fat]- compound lipids lipids that can be hydrolyzed under alkali conditions to generate smaller constituents.* * *Long-Term Intervention with Pravastatin in Ischemic Disease [trial]
* * *lip·id 'lip-əd also lip·ide -.īd n any of various substances that are soluble in nonpolar organic solvents (as chloroform and ether), that with proteins and carbohydrates constitute the principal structural components of living cells, and that include fats, waxes, phospholipids, cerebrosides, and related and derived compounds
* * *n.one of a group of naturally occurring compounds that are soluble in solvents such as chloroform or alcohol, but insoluble in water. Lipids are important dietary constituents, not only because of their high energy value but also because certain vitamins and essential fatty acids are associated with them. The group includes fat, the steroid, phospholipid, and glycolipid.
* * *lip·id (lipґid) any of a heterogeneous group of fats and fatlike substances characterized by being water-insoluble and being extractable by nonpolar (or fat) solvents such as alcohol, ether, chloroform, benzene, etc. All contain as a major constituent aliphatic hydrocarbons. The lipids, which are easily stored in the body, serve as a source of fuel, are an important constituent of cell structure, and serve other biological functions. Lipids may be considered to include fatty acids, neutral fats, waxes, and steroids. Compound lipids comprise the glycolipids, lipoproteins, and phospholipids.
Medical dictionary. 2011.