| SBP | schizobipolar; serotonin-binding protein; spontaneous bacterial peritonitis; steroid-binding plasma ... |
|---|---|
| SSB | short spike burst; sicca syndrome B; single-strand break; single-stranded binding [protein]; stereos... |
| TBA | tertiary butylacetate; testosterone-binding affinity; tetrabutylammonium; thiobarbituric acid; to be... |
| TBI | thyroid-binding index; thyroxine-binding index; tooth-brushing instruction; total-body irradiation; ... |
| TBP | bithionol; testosterone-binding protein; thyroxine-binding protein; total bypass; tributyl phosphate... |
| time constant | That part of a circuit that determines the time interval over which the rate of electrical events will be averaged; in pulmonary physiology, the factors determining rate of flow in the airways. (05 Mar 2000) |
|---|---|
| transformation constant | <physics, radiobiology> The fraction of the amount of a radionuclide that undergoes transition per unit time. Formally: Lamda=dP/dt Where dP is the probability of a given nucleus undergoing spontaneous nuclear transition in the time interval dt. (16 Dec 1997) |
| equilibrium constant | <chemistry> The ratio of the reverse and forward rate constants for a reaction of the type: A + B = AB at equilibrium the equilibrium constant (K) equals the product of the concentrations of reactants divided by the concentration of product and has dimensions of concentration. Kd = (concentration A.concentration B) / (concentration AB). The affinity constant (Ka) is the reciprocal of the equilibrium constant. Dimension: moles per litre. In general the concept of Kd is more readily understood than that of Ka, for example: in considering the conversion of A to AB by the binding of ligand B, the Kd = B when A = AB. Thus Kd is equal to the ligand concentration which produces half maximal conversion (response). (10 Jan 1998) |
| universal gas constant | <radiobiology> R = 8.314 x 10^7 ergs per degree C per mole. (09 Oct 1997) |
| flotation constant | Characteristic sedimentation behaviour of a lipoprotein fraction of plasma in a centrifugal field in a medium of appropriate density, achieved by adding a salt or D2O to the plasma. Synonym: negative S, Svedberg of flotation. (05 Mar 2000) |
| law of constant numbers in ovulation | The number of ova discharged at each ovulation is nearly constant for any given species. (05 Mar 2000) |
| androgen binding protein | A protein secreted by testicular Sertoli cells along with inhibin and mullerian inhibiting substance. Androgen binding protein probably maintains a high concentration of androgen in the seminiferous tubules. (05 Mar 2000) |
| androgen-binding proteins | Carrier proteins produced in the sertoli cells of the testis, secreted into the seminiferous tubules, and transported via the efferent ducts to the epididymis. Participate in the transport of androgens; include also synthetic androgens binding proteins. (12 Dec 1998) |
| antigen-binding site | <immunology> In immune network theory, an idiotope, an antigenic site of an antibody that is responsible for that antibody binding to an antigenic determinant (epitope). Also used of the site on a ligand molecule to which a cell surface receptor binds. (18 Nov 1997) |
| binding | <biochemistry, chemistry, molecular biology> The adherence of molecules to one another, for example, enzymes to substrates, antibodies to antigens, DNA strands to their complementary strands. Binding occurs because the shape and chemical natures of parts of the molecules surfaces are complementary. A common metaphor is the "lock-and-key," used to describe how enzymes fit around their substrate. (14 Nov 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) |
| binding sites | The reactive parts of a macromolecule that directly participate in its specific combination with another molecule. (12 Dec 1998) |
| binding sites, antibody | Local surface sites on antibodies which react with antigen determinant sites on antigens. They are formed from parts of the variable regions of the fab fragment of the immunoglobulin. (12 Dec 1998) |
| calcium-binding protein | <biochemistry> There are two main groups of calcium binding proteins, those that are similar to calmodulin and are called EF hand proteins and those that bind calcium and phospholipid (e.g. Lipocortin) and that have been grouped under the generic name of annexins. Many other proteins will bind calcium, although the binding site usually has considerable homology with the calcium-binding domains of calmodulin. They can act as transport proteins, regulator proteins or activator proteins. There is also a vitamin D-dependent variant which is a protein that plays a fundamental role in the vitamin d mediated transport of calcium in reptiles, amphibians, birds and mammals. It is found in the intestine, kidneys, egg shell gland, brain, and possibly other organs. Its molecular weight is species dependent. (12 May 2002) |
| calmodulin-binding proteins | Proteins which bind calmodulin. They are found in many tissues and have a variety of functions including f-actin cross-linking properties, inhibition of cyclic nucleotide phosphodiesterase and calcium and magnesium atpases. (12 Dec 1998) |