| nucleic acids, nucleotides, and nucleosides | Complex compounds of high molecular weight occurring in living cells. These are basically of two types, ribonucleic (RNA) and deoxyribonucleic (DNA) acids, both of which consist of nucleotides (nucleoside phosphates linked together by phosphate bridges). (12 Dec 1998) |
|---|---|
| nucleotides | The basic building blocks of nucleic acids. They are made up of a nitrogen-containing purine or pyrimidine base linked to a sugar (ribose or deoxyribose) and a phosphate group. (14 Nov 1997) |
| deoxyadenine nucleotides | Adenine nucleotides which contain deoxyribose as the sugar moiety. (12 Dec 1998) |
| deoxycytosine nucleotides | Cytosine nucleotides which contain deoxyribose as the sugar moiety. (12 Dec 1998) |
| deoxyguanine nucleotides | Guanine nucleotides which contain deoxyribose as the sugar moiety. (12 Dec 1998) |
| deoxyuracil nucleotides | Uracil nucleotides which contain deoxyribose as the sugar moiety. (12 Dec 1998) |
| thymine nucleotides | Phosphate esters of thymidine in n-glycosidic linkage with ribose or deoxyribose, as occurs in nucleic acids. (12 Dec 1998) |
| purine | <biochemistry, molecular biology> A heterocyclic compound with a fused pyrimidine/imidazole ring. Planar and aromatic in character. The parent compound for the purine bases of nucleic acids. (18 Nov 1997) |
| purine 5'-nucleotidase | <enzyme> Associated with some immunologic deficiency diseases Registry number: EC 3.1.3.- (26 Jun 1999) |
| purine base | A purine. (05 Mar 2000) |
| purine-free diet | A diet containing a minimal quantity of purine bases (meats); liver, kidney, and sweetbread especially are excluded and replaced by dairy products, fruits, and cereals; alcoholic beverages also are excluded. Synonym: purine-free diet. (05 Mar 2000) |
| purine imidazole-ring cyclase | <enzyme> Recyclises ring-opened purine formamidopyrimidines in irradiated DNA, restoring the c-8 to n-9 band, does not require ATP Registry number: EC 6.3.3.- Synonym: purir cyclase (26 Jun 1999) |
| purine-nucleoside phosphorylase | <enzyme> An enzyme that catalyses the reaction between a purine nucleoside and orthophosphate to form a free purine plus ribose-5-phosphate. Chemical name: Purine-nucleoside:orthophosphate ribosyltransferase Registry number: EC 2.4.2.1 (12 Dec 1998) |
| purine permease | <chemical> Enzyme in transport system of purines in yeast pichia guillermondii Chemical name: permease, purine (26 Jun 1999) |
| purine phosphoribosyltransferase | <enzyme> Specific purine phosphoribosyltransferases are EC 2.4.2.7 and 2.4.2.8. Registry number: EC 2.4.2.- (26 Jun 1999) |