2,5-Diaminovaleric acid; the l-isomer is the amino acid formed when l-arginine is hydrolyzed by arginase; not a constituent of proteins, but an important intermediate in the urea cycle; elevated levels seen in certain defects of the urea cycle.
- o. δ-aminotransferase an enzyme that will reversibly catalyze the reaction of α-ketoglutarate and l-o. to form l-glutamate and l-glutamate γ-semialdehyde; a deficiency of this enzyme will result in gyrate atrophy of the choroid and retina. SYN: o. transaminase.
- o. carbamoyltransferase an enzyme catalyzing formation of l-citrulline and orthophosphate from l-o. and carbamoyl phosphate; a part of the urea cycle; a deficiency of this enzyme will result in ammonia intoxication and impaired urea formation. SYN: o. transcarbamoylase.
- o. decarboxylase an enzyme catalyzing the decarboxylation of l-o. to putrescine and CO2; first step in polyamine biosynthesis.
- o. transaminase SYN: o. δ-aminotransferase.
- o. transcarbamoylase SYN: o. carbamoyltransferase.

* * *

or·ni·thine 'ȯr-nə-.thēn n a crystalline amino acid C5H12N2O2 that functions esp. in urea production as a carrier by undergoing conversion to citrulline and then arginine in reaction with ammonia and carbon dioxide followed by recovery along with urea by enzymatic hydrolysis of arginine

* * *

an amino acid produced in the liver as a by-product during the conversion of ammonia to urea.

* * *

or·ni·thine (orґnĭ-thēn) an amino acid produced in the urea cycle by the splitting off of urea from arginine and is itself converted into citrulline. On decomposition, it gives rise to putrescine.

Medical dictionary. 2011.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Ornithine — Formule topologique de l ornithine. Général No CAS …   Wikipédia en Français

  • ornithine — ornithine. См. орнитин. (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.

  • ornithine — ● ornithine nom féminin Acide aminé basique, glycoformateur et transaminable, jouant un rôle dans le cycle de l uréogenèse. (Le dérivé guanidinique est l arginine.) …   Encyclopédie Universelle

  • ornithine — [ôr′nə thēn΄, ôr′nəthin] n. [< Gr ornis, bird (see ORNITHO ) + INE3] a nonessential amino acid, NH2 (CH2) 3CH(NH2)COOH, found in animals as a product of urea formation from proteins and in the excrement of birds …   English World dictionary

  • Ornithine — L Ornithine IUPAC name L Ornithine …   Wikipedia

  • ornithine — noun Etymology: International Scientific Vocabulary ornithuric acid (a compound of which ornithine is a component, found in the urine of birds) + 2 ine Date: 1881 a crystalline amino acid C5H12N2O2 that functions especially in urea production as… …   New Collegiate Dictionary

  • ornithine — ornitinas statusas T sritis chemija formulė H₂N(CH₂)₃CH(NH₂)COOH santrumpa( os) Orn atitikmenys: angl. ornithine rus. орнитин ryšiai: sinonimas – 2,5 diaminopentano rūgštis …   Chemijos terminų aiškinamasis žodynas

  • ornithine — noun an amino acid that does not occur in proteins but is important in the formation of urea • Hypernyms: ↑amino acid, ↑aminoalkanoic acid * * * ornithine Chem. (ˈɔːnɪθaɪn) [f. Gr. ὀρνῑθ bird + ine5.] A base, C5H12N2O2, which enters into the… …   Useful english dictionary

  • Ornithine transcarbamylase — Ornithine carbamoyltransferase Human OTC trimer. From PDB 1OTH …   Wikipedia

  • Ornithine decarboxylase — Identifiers EC number CAS number 9024 60 6 …   Wikipedia

  • Ornithine translocase deficiency — Classification and external resources Ornithine ICD 9 …   Wikipedia

Share the article and excerpts

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