| lipid | <chemical> Any of a heterogeneous group of flats and fatlike substances characterised 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. (18 Nov 1997) |
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| lipid A | The lipid associated with polysaccharide in the lipopolysaccharide of gram-negative bacterial cell walls. (18 Nov 1997) |
| lipid A 4'-phosphatase | <enzyme> Involved in lipid a biosynthesis in rhizobium leguminosarum Registry number: EC 3.1.3.- Synonym: 2-keto-3-deoxyoctulosonate-activated 4'-phosphatase, kdo-activated lipid a 4'-phosphatase (26 Jun 1999) |
| lipid A disaccharide synthase | <enzyme> Udp-diacyl-n-acetylglucosamine plus 2,3-diacyl-n-acetylglucosamine-1-phosphate yields 2',3'-diacyl-glcn-(beta 1-6)-2,3-diacyl-glcn-1-p plus udp Registry number: EC 2.4.1.182 Synonym: 2,3-diacyl-n-acetylglucosamine diacyl-n-acetylglucosaminyltransferse, lipid a synthase (26 Jun 1999) |
| lipid bilayer | <biochemistry> A lamellar organisation of phospholipids that are packed as a bilayer with hydrophobic acyl tails inwardly directed and polar head groups on the outside surfaces. It is this bilayer that forms the basis of membranes in cells, though in most cellular membranes a very substantial proportion of the area may be occupied by integral proteins. The triple layered appearance of membranes seen in electron microscopy is thought to arise because the osmium tetroxide binds to the polar regions leaving a central, unstained, hydrophobic region. (31 Dec 1997) |
| lipid bilayers | Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes. (12 Dec 1998) |
| lipid granulomatosis | <dermatology, pathology> An accumulation of an excess of lipids in the body due to disturbance of lipid metabolism and marked by the formation of foam cells in skin lesions. (16 Dec 1997) |
| lipid histiocytosis | Histiocytosis with cytoplasmic accumulation of lipid, either phospholipid (Niemann-Pick disease) or glucocerebroside (Gaucher's disease). (05 Mar 2000) |
| lipid keratopathy | Occurrence of fats in an area of corneal vascularization. (05 Mar 2000) |
| lipid mobilization | The breakdown of stored triglyceride in adipose tissue with the release of free fatty acids and glycerol. Depot fat hydrolysis is catalyzed by a lipase in response to pituitary lipid mobilization factors (lmf), various hormones, serotonin, or hepatotoxins such as carbon tetrachloride. (12 Dec 1998) |
| lipid peroxidation | Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor. (12 Dec 1998) |
| lipid peroxides | Peroxides produced in the presence of a free radical by the oxidation of unsaturated fatty acids in the cell in the presence of molecular oxygen. The formation of lipid peroxides results in the destruction of the original lipid leading to the loss of integrity of the membranes. They therefore cause a variety of toxic effects in vivo and their formation is considered a pathological process in biological systems. Their formation can be inhibited by antioxidants, such as vitamin e, structural separation or low oxygen tension. (12 Dec 1998) |
| lipid pneumonia | Lipoid pneumonia, pulmonary condition marked by inflammatory and fibrotic changes in the lungs due to the inhalation of various oily or fatty substances, particularly liquid petrolatum, or resulting from accumulation in the lungs of endogenous lipid material, either cholesterol from obstructive pneumonitis or following fracture of a bone; phagocytes containing lipid are usually present. Synonym: oil pneumonia. (05 Mar 2000) |
| lipid profile | Pattern of lipids in the blood. (A lipid profile usually includes the total cholesterol, high density lipoprotein (hdl) cholesterol, triglycerides, and the calculated low density lipoprotein (ldl) cholesterol. (12 Dec 1998) |
| lipid storage diseases | A series of disorders due to inborn errors in lipid metabolism resulting in the abnormal accumulation of lipids in the wrong places (examples include gaucher, fabry and niemann-pick diseases and metachromatic leukodystrophy). (12 Dec 1998) |
| anisotropic lipid | A lipid in the form of doubly refractive droplets. (05 Mar 2000) |
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| annular lipid | The layer(s) of lipid bound to and/or surrounding an integral membrane protein. (05 Mar 2000) |
| brain lipid | Impure cephalin possessing marked haemostatic action when locally applied. (05 Mar 2000) |
| galactose-diphosphoglycosyl carrier lipid synthetase | <enzyme> Catalyses synthesis of gcl-pp-gal from udp gal and p-gcl; also catalyses exchange between the uridylyl moiety of udpgal and ump Registry number: EC 2.4.1.- (26 Jun 1999) |
| pneumonia, lipid | Pneumonia due to aspiration or inhalation of various oily or fatty substances. (12 Dec 1998) |
| neutral lipid storage disease | <syndrome> Congenital ichthyosis, leukocyte vacuoles, and variable involvement of other organ systems. Synonym: neutral lipid storage disease. (05 Mar 2000) |
| disease, lipid storage | A series of disorders due to inborn errors in lipid metabolism resulting in the abnormal accumulation of lipids in the wrong places (Examples include Gaucher, Fabry and Niemann-Pick diseases and metachromatic leukodystrophy). (12 Dec 1998) |
| inositol lipid | A membrane-anchored phospholipid that transduces hormonal signals by stimulating the release of any of several chemical messengers. (09 Oct 1997) |
| isotropic lipid | A lipid occurring in the form of singly refractive droplets. (05 Mar 2000) |