energetics
| incidence density | The person-time incidence rate. (05 Mar 2000) |
|---|---|
| intermediate density lipoprotein | Class of lipoproteins formed in degradation of very-low-density lipoproteins; about half are cleared quickly from the plasma into the liver by receptor-mediated endocytosis; the other half are degraded into low density lipoproteins. (05 Mar 2000) |
| inverse density dependence | <epidemiology> See density dependence. (05 Dec 1998) |
| optical density | 1. <chemistry, investigation> Absorbance is defined as a logarithmic function of the percent transmission of a wavelength of light through a liquid. 2. <microbiology> This can be used as a measure of the amount of light absorbed by a suspension of bacterial cells or a solution of an organic molecule, it is measured by a colourimeter or spectrophotometer. Absorbance values are used to plot the growth of bacteria in suspension cultures and to gauge the purity and concentration of molecules (such as proteins) in solution. See: absorption. (15 Jan 1998) |
| organismal density | <microbiology> Number of organisms or items per unit area or volume. (09 Oct 1997) |
| familial high density lipoprotein deficiency | Familial high {density lipoprotein deficiency}; a heritable disorder of lipid metabolism characterised by almost complete absence from plasma of high density lipoproteins, and by storage of cholesterol esters in foam cells, tonsillar enlargement, an orange or yellow-gray colour of the pharyngeal and rectal mucosa, hepatosplenomegaly, lymph node enlargement, corneal opacity, and peripheral neuropathy; autosomal recessive inheritance. Synonym: familial high {density lipoprotein deficiency}, Tangier disease. Origin: G. An-, priv., + alpha, a, + lipoprotein + -aemia, blood (05 Mar 2000) |
| low density lipoprotein | <biochemistry> A lipoprotein substances (combination of a fat and a protein) which acts as a carrier for cholesterol and fats in the bloodstream. High levels of low density lipoprotein are considered a positive risk factor for the development of coronary artery disease. Less than 130 mg/dl is desirable, 130 to 159 mg/dl is borderline high, over 160 is considered high. Acronym: LDL (10 Jan 1998) |
| low density lipoprotein receptor | <biochemistry> A cell surface protein that mediates the endocytosis of low density lipoprotein by cells. Genetic defects in low density lipoprotein receptors lead to abnormal serum levels of low density lipoprotein and hypercholesterolaemia. (16 Mar 1998) |
| low-density lipoprotein receptors | Receptors on the surface of cells, especially liver cells, which bind to low density lipoprotein and promote clearance of LDL from the plasma. (05 Mar 2000) |
| activation energy | <chemistry> The amount of energy (expressed in joules) that is needed to convert all the molecules in one mole of a reacting substance from a ground state to the transition state. (06 May 1997) |
| binding energy | <chemistry, radiobiology> The binding energy of a nucleus is the minimum energy required to dissociate it into its component neutrons and protons. Neutron or proton binding energies are those required to remove a neutron or proton, respectively, from a nucleus. Electron binding energy is that required to remove an electron from an atom or a molecule. (16 Dec 1997) |
| bioelectric energy sources | Implantable devices which convert biological energy (chemical energy of the metabolism of continuously regenerating body fluids or mechanical energy of periodic movements) to electrical energy. The sources include biogalvanic cells, biofuel cells, and ionic concentration cells. (12 Dec 1998) |
| biomass energy | See Bioenergy. (05 Dec 1998) |
| bond dissociation energy | This is the energy needed to break the bonds between two linked atoms. (09 Oct 1997) |
| bond energy | The energy needed to break a molecular bond. (09 Oct 1997) |