lipid

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lipid

 [lip´id]
a group of substances comprising fatty, greasy, oily, and waxy compounds that are insoluble in water and soluble in nonpolar solvents, such as hexane, ether, and chloroform.

Simple lipids are the triglycerides or neutral fats. Each triglyceride molecule is composed of one molecule of glycerol joined by ester linkages to three fatty acid molecules. They are an important source of fuel to the body and a much lighter form of energy storage than carbohydrate.

Compound lipids are important structural components of cell membranes. Phospholipids include lecithin and the cephalins, which are composed of fatty acids linked to phosphatidic acid, and the sphingomyelins, which are composed of fatty acids linked to sphingosine. Glycolipids are composed of a carbohydrate chain and fatty acids linked to sphingosine or ceramide. Cholesterol is a steroid alcohol. Another important function of the phospholipids is as lung surfactants.

Intravenous lipid emulsions can be administered to patients with a deficiency of essential fatty acids.

lip·id

(lip'id),
"Fat-soluble," an operational term describing a solubility characteristic, not a chemical substance, that is, denoting substances extracted from animal or vegetable cells by nonpolar solvents; included in the heterogeneous collection of materials thus extractable are fatty acids, 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]

lipid

(lĭp′ĭd, lī′pĭd) also

lipide

(lĭp′īd′, lī′pīd′)
n.
Any of a group of organic compounds, including the fats, oils, waxes, sterols, and triglycerides, that are insoluble in water but soluble in nonpolar organic solvents, are oily to the touch, and together with carbohydrates and proteins constitute the principal structural material of living cells.

lip·id′ic adj.

LIPID

Cardiology A clinical trial–Long-Term Intervention with Pravastatin in Ischemic Disease–which evaluated preventing cardiovascular M&M with pravastatin in Pts with CAD and a range of initial cholesterol levels

lip·id

(lip'id)
"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 acids, glycerides, glyceryl ethers, phospholipids, sphingolipids, long-chain alcohols, waxes, terpenes, steroids, and "fat-soluble" vitamins such as A, D, and E.

lipid

a biological compound composed of glycerol and fatty acid components, containing carbon, hydrogen and oxygen together with other elements such as nitrogen and phosphorus. Lipids (or fats) are structural components of cell membranes and nervous tissue, and are important sources of energy, being stored in various parts of the body (see ADIPOSE TISSUE). They are important insulators and mechanical protectors. Their large molecular size makes lipids insoluble in water, but soluble in organic solvents such as acetone and ether. There are five lipid groups:

triglycerides (fats and oils)

phospholipids

glycolipids

sterols and steroids

waxes

Lipid

A greasy organic compound that cannot be dissolved in water. Triglycerides, which are broken down by lipase, are one type of blood lipid.

lip·id

(lip'id)
"Fat-soluble," operational term describing a solubility characteristic, not a chemical substance, i.e., denoting substances extracted from animal or vegetable cells by nonpolar solvents.