lipid A


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Related to lipid A: endotoxin, O antigen

lipid A

the glycolipid component of lipopolysaccharide responsible for its endotoxic activity.

lip·id A

(lip'id)
The glycolipid component of lipopolysaccharide responsible for its endotoxic activity.

lipid

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 oxidizable substrate to the body and have a greater caloric density (2.25 times) 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.

lipid A
a component of the cell wall of gram-negative bacteria, responsible for their toxic properties.
lipid pneumonia
see lipid pneumonia.
protected l's
fats treated to protect them against microbial degeneration in the rumen.
lipid transport disease
a group of diseases in which there is a disorder of lipid metabolism with abnormal levels or types of lipoproteins in the blood, e.g. hyperlipoproteinemia, hyperlipemia.