| 释义 |
purineenUK
pu·rine P0668700 (pyo͝or′ēn′)n.1. A double-ringed, crystalline organic base, C5H4N4, that is the parent compound of a large group of biologically important compounds.2. Any of a group of substituted derivatives of purine, including the nitrogen bases adenine and guanine, which are components of nucleic acids. Uric acid, caffeine, theobromine, and theophylline are also purines.
[German Purin : blend of Latin pūrus, clean; see pure, and New Latin ūricus, uric (from Greek ouron, urine) + -in, -in, -ine.]purine (ˈpjʊəriːn) or purinn1. (Elements & Compounds) a colourless crystalline solid that can be prepared from uric acid. Formula: C5H4N42. (Elements & Compounds) Also called: purine base any of a number of nitrogenous bases, such as guanine and adenine, that are derivatives of purine and constituents of nucleic acids and certain coenzymes[C19: from German Purin; see pure, uric, -ine2]pu•rine (ˈpyʊər in, -ɪn)
n. 1. a white, crystalline compound, C5H4N4, from which is derived a group of compounds including uric acid, xanthine, and caffeine. 2. one of several purine derivatives, esp. the bases adenine and guanine, which are fundamental constituents of nucleic acids. [1895–1900; < German Purin. See pure, uric, -ine2] pu·rine (pyo͝or′ēn′) Any of a group of organic compounds containing two rings of alternating carbon and nitrogen atoms. Purines include caffeine and uric acid, as well as the two bases adenine and guanine, which are components of DNA and RNA.Thesaurus| Noun | 1. | purine - any of several bases that are derivatives of purinealkali, base - any of various water-soluble compounds capable of turning litmus blue and reacting with an acid to form a salt and water; "bases include oxides and hydroxides of metals and ammonia"adenine, A - (biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNAguanine, G - a purine base found in DNA and RNA; pairs with cytosine | | 2. | purine - a colorless crystalline organic base containing nitrogen; the parent compound of various biologically important substancesalkali, base - any of various water-soluble compounds capable of turning litmus blue and reacting with an acid to form a salt and water; "bases include oxides and hydroxides of metals and ammonia" |
Translations
purineenUK
purine, type of organic base found in the nucleotidesnucleotide
, organic substance that serves as a monomer in forming nucleic acids. Nucleotides consist of either a purine or a pyrimidine base, a ribose or deoxyribose, and a phosphate group. Adenosine triphosphate serves as the principle energy carrier for the cell's reactions.
..... Click the link for more information. and nucleic acidsnucleic acid,
any of a group of organic substances found in the chromosomes of living cells and viruses that play a central role in the storage and replication of hereditary information and in the expression of this information through protein synthesis.
..... Click the link for more information. of plant and animal tissue. The German chemist Emil Fischer did much of the basic work on purines and introduced the term into the chemical literature in the early 20th cent. The two major purines of almost universal distribution in living systems are adenineadenine
, organic base of the purine family. Adenine combines with the sugar ribose to form adenosine, which in turn can be bonded with from one to three phosphoric acid units, yielding the three nucleotides adenosine monophosphate, adenosine diphosphate, and adenosine
..... Click the link for more information. and guanineguanine
, organic base of the purine family. It was reported (1846) to be in the guano of birds; later (1879–84) it was established as one of the major constituents of nucleic acids.
..... Click the link for more information. .Purine A heterocyclic organic compound ( 1 ) containing  (1) fused pyrimidine and imidazole rings. A number of substituted purine derivatives occur in nature; some, as components of nucleic acids and coenzymes, play vital roles in the genetic and metabolic processes of all living organisms. See Coenzyme, Nucleic acid Purines are generally white solids of amphoteric character. They can form salts with both acids and bases. Conjugated double bonds in purines results in aromatic chemical properties, that confers considerable stability, and accounts for their strong ultraviolet absorption spectra. With the exception of the parent compound, most substituted purines have low solubilities in water and organic solvents. The purine bases, adenine ( 2 ) and guanine ( 3 ),  (2) together with pyrimidines, are fundamental components of all nucleic acids. Certain methylated derivatives of adenine and guanine are also present in some nucleic acids in low amounts. In biological systems, hypoxanthine ( 4 ),  (3) adenine, and guanine occur mainly as their 9-glycosides, the sugar being either ribose or 2-deoxyribose. Such compounds are termed nucleosides generically, and inosine (hypoxanthine nucleoside), adenosine, or guanosine specifically. The principal nucleotides contain 5′-phosphate groups, as in guanosine 5′-phosphate (GTP) and adenosine 5′-triphosphate (ATP). Most living organisms are capable of synthesizing purine compounds. The sequence of enzymatic reactions by which the initial purine product, inosine 5′-phosphate, is formed utilizes glycine, carbon dioxide, formic acid, and amino groups derived from glutamine and aspartic acid. Adenosine 5′-phosphate and guanosine 5′-phosphate are formed from inosine 5′-phosphate. Metabolic degradation of purine derivatives may also occur by hydrolysis of nucleotides and nucleosides to the related free bases. Deamination of adenine and guanine produces hypoxanthine and xanthine ( 5 ), both of which may be oxidized to uric acid ( 6 ).  (4) See Uric acid Purine-related compounds have been investigated as potential chemotherapeutic agents. In particular, 6-mercaptopurine, in the form of its nucleoside phosphate, inhibits several enzymes required for synthesis of adenosine and guanosine nucleotides, and thus proves useful in selectively arresting the growth of tumors. The pyrazolopyrimidine has been used in gout therapy. As a purine analog, this agent serves to block the biosynthesis of inosine phosphate, as well as the oxidation of hypoxanthine and xanthine to uric acid. As a result of its use, overproduction of uric acid is prevented and the primary cause of gout is removed. See Chemotherapy, Pyrimidine purine[′pyu̇‚rēn] (biochemistry) A heterocyclic compound containing fused pyrimidine and imidazole rings; adenine and guanine are the purine components of nucleic acids and coenzymes. purineenUK
purine [pu´rēn] a heterocyclic compound that is the nucleus of the purine bases such as adenine and guanine (which occur in DNA and RNA), and xanthine and hypoxanthine.pur·ine (Pur), (pyūr'ēn, -rin), The parent substance of adenine, guanine, and other naturally occurring purine "bases."purine (pyo͝or′ēn′)n.1. A double-ringed, crystalline organic base, C5H4N4, that is the parent compound of a large group of biologically important compounds.2. Any of a group of substituted derivatives of purine, including the nitrogen bases adenine and guanine, which are components of nucleic acids. Uric acid, caffeine, theobromine, and theophylline are also purines.pu·rine (pyūr'ēn) The parent substance of adenine, guanine, and other naturally occurring so-called purine bases; not known to exist as such in mammals. purine one of two types of base found in NUCLEIC ACIDS, having a double ring structure; see ADENINE and GUANINE. Purines always pair with PYRIMIDINES in the two strands of DNA, ensuring a parallel-sided molecule.PurineA white crystalline substance that is one of the building blocks of DNA. Uric acid is produced when purine is broken down in the body.Mentioned in: Gout, Uric Acid TestspurineenUK
Related to purine: uric acid, low purine dietWords related to purinenoun any of several bases that are derivatives of purineRelated Words- alkali
- base
- adenine
- A
- guanine
- G
noun a colorless crystalline organic base containing nitrogenRelated Words |