| complementary base pairs | <molecular biology> The crucial property of DNA is that the two strands are complementary: Guanine and cytosine are complementary and pair up through their hydrogen bonds, as are adenine and thymine that only form two hydrogen bonds. (adenine and uracil in RNA). (18 Nov 1997) |
|---|---|
| wobble base | The 3' codon base that is less strictly specified in the genetic code. See: wobble, wobble hypothesis. (05 Mar 2000) |
| conjugate acid-base pair | In prototonic solvents (e.g., H2O, NH3, acetic acid), two molecular species differing only in the presence or absence of a hydrogen ion (e.g., carbonic acid/bicarbonate ion or ammonium ion/ammonia); the basis of buffer action. (05 Mar 2000) |
| cranial base | The sloping floor of the cranial cavity. It comprises both the external base of skull (external view) and the internal base of skull (internal view). See: internal base of skull. Synonym: basis cranii, cranial base. (05 Mar 2000) |
| cyanine green G base | <chemical> Pharmacological action: dye Synonym: d.c. Green no. 6, 1,4-di-4-toluidinoanthraquinone, solvent green 3 (26 Jun 1999) |
| pressor base | One of several products of intestinal putrefaction believed to cause functional hypertension when absorbed, any alkaline substance that raises blood pressure. Synonym: pressor amine, pressor substance. (05 Mar 2000) |
| Schiff base | The reaction of a primary amine with an aldehyde or ketone yields an imine sometimes called a Schiff base. When an arylamine is used the Schiff base may form an intermediate in a staining reaction, for example for polysaccharides. (18 Nov 1997) |
| purine base | A purine. (05 Mar 2000) |
| pyrimidine base | <biochemistry> A family of 6-membered heterocyclic compounds occurring in nature in a wide variety of forms. They are planar and aromatic in character and include several nucleic acid constituents (cytosine, thymine, and uracil) and form the basic structure of the barbiturates. It is the parent compound of the pyrimidine bases of nucleic acid. (21 Jun 2000) |
| shellac base | A resinous wafer adapted to maxillary or mandibular casts to form baseplates. (05 Mar 2000) |
| hydroxy-Y base | <chemical> Chemical name: 1h-imidazo(1,2-a)purine-7-butanoic acid, 4,9-dihydro-beta-hydroxy-alpha-((methoxycarbonyl)amino)-4,6-dimethyl-9-oxo-, methyl ester Synonym: alpha-(carboxyamino)-beta-hydroxy-4,9-dihydro-4,6- dimethyl-9-oxo-1h-imidazo(1,2-a)purine-7-butyric acid dimethyl ester (26 Jun 1999) |
| negative base excess | A measure of metabolic acidosis, usually predicted from the Siggaard-Andersen nomogram; the amount of strong alkali that would have to be added per unit volume of whole blood to titrate it to pH 7.4 while at 37캜 and at a carbon dioxide pressure of 40 mm Hg. (05 Mar 2000) |
| nitrogenous base | <biochemistry> A nitrogen-containing molecule having the chemical properties of a base. (09 Oct 1997) |
| nucleic acid base | A purine or pyrimidine; found in naturally occurring nucleic acids such as DNA. (05 Mar 2000) |
| nucleinic base | An obsolete term for purine. (05 Mar 2000) |