Coenzyme
A substance that enhances the action of an enzyme. (An enzyme is a protein that functions as a catalyst to mediate and speed a chemical reaction). Coenzymes are small molecules. They cannot by themselves catalyze a reaction but they can help enzymes to do so. In technical terms, coenzymes are organic nonprotein molecules that bind with the protein molecule (apoenzyme) to form the active enzyme (holoenzyme). A number of the water-soluble vitamins such as vitamins B1, B2 and B6 serve as coenzymes.
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A substance (excluding solo metal ions) that enhances or is necessary for the action of enzymes; coenzymes are of smaller molecular size than the enzymes themselves, are dialyzable and relatively heat-stable, and are usually easily dissociable from the protein portion of the enzyme; several vitamins are c. precursors. SYN: cofactor (1).

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co·en·zyme (')kō-'en-.zīm n a thermostable nonprotein compound that forms the active portion of an enzyme system after combination with an apoenzyme compare ACTIVATOR (1)
co·en·zy·mat·ic (.)kō-.en-zə-'mat-ik, -(.)zī- adj
co·en·zy·mat·i·cal·ly -i-k(ə-)lē adv

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n.
a nonprotein organic compound that, in the presence of an enzyme, plays an essential role in the reaction that is catalysed by the enzyme. Coenzymes, which frequently contain the B vitamins in their molecular structure, include coenzyme A, FAD, and NAD.

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co·en·zyme (ko-enґzīm) an organic nonprotein molecule, frequently a phosphorylated derivative of a water-soluble vitamin, that binds with the protein molecule (apoenzyme) to form the active enzyme (holoenzyme).

Medical dictionary. 2011.

Look at other dictionaries:

  • coenzyme — [ koɑ̃zim ] n. m. ou f. • co enzyme 1909; de co et enzyme ♦ Biochim. Substance organique non protéique, qui peut s unir à un apoenzyme pour donner un enzyme actif. Coenzyme A : dérivé de l acide pantothénique jouant un rôle essentiel dans les… …   Encyclopédie Universelle

  • coenzyme — co*en zyme (k[ o]*[e^]n z[imac]m), (Biochem.) a molecule that is essential for the activity of some enzymes; it may exist free in solution within a living organism, but functions by binding to an enzyme to assist in catalyzing a reaction. The… …   The Collaborative International Dictionary of English

  • coenzyme — ☆ coenzyme [kō en′zīm΄ ] n. an organic substance of low molecular weight that is not protein and that can unite with a given protein, apoenzyme, to form an active enzyme complex …   English World dictionary

  • Coenzyme — Coenzymes are small organic non protein molecules that carry chemical groups between enzymes. [cite web |url=http://www.chem.qmul.ac.uk/iupac/bioinorg/CD.html#33 |title=Glossary of Terms Used in Bioinorganic Chemistry: Coenzymes |accessdate=2007… …   Wikipedia

  • Coenzyme — A l exception des hydrolases, la plupart des enzymes sont constituées de deux éléments : une apoenzyme, de nature protéique[1], donc codé par le génome, impliquée dans la reconnaissance du substrat et sa liaison, un coenzyme, molécule… …   Wikipédia en Français

  • coenzyme — Either: low molecular weight intermediate that transfers groups between reactions (eg. NAD), or: catalytically active low molecular weight component of an enzyme (eg. haem). Coenzyme and apoenzyme together constitute the holoenzyme …   Dictionary of molecular biology

  • coenzyme — n. a nonprotein organic compound that, in the presence of an enzyme, plays an essential role in the reaction that is catalysed by the enzyme. Coenzymes, which frequently contain the B vitamins in their molecular structure, include coenzyme A, FAD …   The new mediacal dictionary

  • coenzyme — kofermentas statusas T sritis chemija apibrėžtis Nebaltyminė aktyvioji fermento dalis. santrumpa( os) Co atitikmenys: angl. coenzyme rus. кофермент ryšiai: sinonimas – koenzimas …   Chemijos terminų aiškinamasis žodynas

  • coenzyme — noun Date: 1947 a thermostable nonprotein compound that forms the active portion of an enzyme system after combination with an apoenzyme • coenzymatic adjective • coenzymatically adverb …   New Collegiate Dictionary

  • Coenzyme — Kofaktoren, Koenzyme und Kosubstrate sind Bezeichnungen für verschiedene Einteilungen von Stoffen, die durch ihre Interaktion mit Enzymen biochemische Reaktionen beeinflussen. Es werden dabei organische Moleküle und auch Ionen (meist Metallionen) …   Deutsch Wikipedia

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