/nooh"klee euh suyd', nyooh"-/, n. Biochem.
any of the class of compounds derived by the hydrolysis of nucleic acids or nucleotides, consisting typically of deoxyribose or ribose combined with adenine, guanine, cytosine, uracil, or thymine.
[1910-15; NUCLE(IC) + -OSE2 + -IDE]

* * *

Any of a class of organic compounds, including structural subunits of nucleic acids.

Each consists of a molecule of a five-carbon sugar (ribose in RNA, deoxyribose in DNA) and a nitrogen-containing base, either a purine or a pyrimidine. The base uracil occurs in RNA, thymine in DNA, and adenine, guanine, and cytosine in both, as part of the nucleosides uridine, deoxythymidine, adenosine or deoxyadenosine, guanosine or deoxyguanosine, and cytidine or deoxycytidine. Nucleosides usually have a phosphate group attached, forming nucleotides. Usually obtained by decomposition of nucleic acids, nucleosides are important in physiological and medical research. Those that are not part of nucleic acids include puromycin and certain other antibiotics produced by fungi.

* * *

      a structural subunit of nucleic acids, the heredity-controlling components of all living cells, consisting of a molecule of sugar linked to a nitrogen-containing organic ring compound. In the most important nucleosides, the sugar is either ribose or deoxyribose, and the nitrogen-containing compound is either a pyrimidine (cytosine, thymine, or uracil) or a purine (adenine or guanine).

      Nucleosides are usually obtained by chemical or enzymatic decomposition of nucleic acids. Details of the structures of several natural nucleosides determined in the period 1891–1911 include the identities of the sugars and the nitrogenous compounds, the size of the ring of atoms in the sugar molecules, and the point of attachment between the two components. Chemical syntheses of adenosine and guanosine were described in 1948; since that time there has been rapid progress in the synthesis of nucleosides and their combination into nucleic acids. Puromycin and certain other antibiotics are nucleosides produced by molds or fungi.

* * *

Universalium. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • nucléoside — [ nykleozid ] n. m. • 1907; de nuclé(o) et oside ♦ Biochim. Produit de décomposition partielle d un nucléide, constitué par du ribose ou du désoxyribose et une base purique ou pyrimidique. ● nucléoside nom masculin Composé formé par l union… …   Encyclopédie Universelle

  • Nucleoside — Nucléoside Les nucléosides sont des glycosylamines faites par le rattachement d une nucléobase à un cycle ribose. Dans les cellules, les nucléosides peuvent être phosphorylés par des kinases spécifiques, ce qui produit des nucléotides, les… …   Wikipédia en Français

  • nucleoside — ucleoside n. (Biochem.) A type of molecule found in all living organisms, present mostly in chemically combined form as a component of nucleic acids, and also in smaller amounts in free form, consisting of a pentose sugar bound to a purine or… …   The Collaborative International Dictionary of English

  • nucleoside — nucleoside. См. нуклеозид. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Nucleoside — Nucleoside, Verbindungen einer Purin oder Pyrimidinbase mit einer Pentose (Ribose oder Desoxyribose); Bestandteile der ⇒ Nucleotide. N. sind z.B. Adenosin, Cytidin, Uridin, Thymidin, Guanosin. Die N. sind N glykosidische Verbindungen, d.h. ein N… …   Deutsch wörterbuch der biologie

  • nucleoside — [no͞o′klē ō sīd΄, nyo͞o′klē ō sīd΄] n. [< NUCLEO + OSE2 + IDE] any of various compounds consisting of a purine or pyrimidine base linked to a carbohydrate: a major component of a nucleotide …   English World dictionary

  • Nucleoside — Nitrogenous base Nucleoside Deoxynucleoside Adenine Adenosine A …   Wikipedia

  • Nucleoside — Die Artikel Nukleotid und Nukleoside überschneiden sich thematisch. Hilf mit, die Artikel besser voneinander abzugrenzen oder zu vereinigen. Beteilige dich dazu an der Diskussion über diese Überschneidungen. Bitte entferne diesen Baustein erst… …   Deutsch Wikipedia

  • Nucléoside —  Ne doit pas être confondu avec nucléotide. Les nucléosides sont des glycosylamines constitués d une nucléobase (ou base) liée à un ribose ou un désoxyribose via une liaison glycosidique. Parmi les nucléosides, on retrouve par exemple la… …   Wikipédia en Français

  • nucleoside — A base (purine or pyrimidine) that is covalently linked to a 5 carbon (pentose) sugar. When the sugar is ribose, the nucleoside is a ribonucleoside; when it is 2 deoxyribose, the nucleoside is a deoxyribonucleoside. See: nucleotide …   Glossary of Biotechnology

  • nucleoside — nu·cle·o·sì·de s.m. TS biochim. composto organico presente nelle nucleoproteine derivante dalla scissione di un nucleotide, formato da uno zucchero, spec. pentoso o esoso, e legato a un composto basico azotato {{line}} {{/line}} DATA: 1933. ETIMO …   Dizionario italiano

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”