Oxidation-reduction reactions Oxidoreductase

Metal ions in the form of organometallic complexes such as the iron atom in heme can undergo one-electron transfers in oxidation-reduction reactions catalyzed by oxidoreductases with associated cytochromes. 

Oxidoreductases, which catalyze oxidation-reduction reactions and are acting, for example, on aldehyde or keto groups. An important application is the synthesis of chiral molecules, especially chiral PFCs (22 out of 38 chiral products produced on large industrial scale are already made using biocatalysis). 

Actually, such an overall reaction occurs in living systems by a complicated series of individual steps. Some of these steps involve oxidation. The enzymes that bring about oxidation in the presence of free 02 are called oxidases. In general, biological oxidation-reduction reactions are catalyzed by oxidoreductase enzymes. 

The oxidoreductase class of biocatalysts is one of the most common of all biological reactions, comprising dehydrogenases, oxidases, and reductases. All these enzymes act on substrates through the transfer of electrons with various co-factors or co-enzymes serving as acceptor molecules. Only a select group of reactions will be discussed because of space limitations, so the reader is referred to other texts for more in-depth discussions of other oxidation-reduction reactions.17 20 25-28... 

Oxidoreductases comprise a large class of enzymes that catalyze biological oxidation/reduction reactions. Because so many chemical transformation processes involve oxidation/reduction processes, the idea of developing practical applications of oxidoreductase enzymes has been a very attractive, but quite elusive, goal for many years [83], Applications have been sought for the production of pharmaceuticals, synthesis and modification of polymers, and the development of biosensors for a variety of clinical and analytical applications [83], In recent years, the use of oxido-reductive enzymes to catalyze the removal of aromatic compounds from... 

Enzymes are placed in various major categories indicated by the first number of the EC number, namely (reaction catalysed in parentheses) (a) oxidoreductases (oxidation-reduction reactions) (b) transferases (transfer of chemical groups e.g. phosphoryl transfer) (c) hydrolases (hydrolysis or cleavage of bonds involving reaction with H20) (d) lyases (cleavage of C-C, C-O and C-N bonds and often yielding a double bond) (e) isomerases... 

OXIDOREDUCTASE—CATALYZES OXIDATION-REDUCTION REACTIONS. Oxygenase—an oxidoreductase that catalyzes the addition of oxygen into a molecule. Example ... 

The wide range of types of oxidation/reduction reactions in foods suggests an enormous potential for oxidoreductases. 

Oxidoreductases. Oxidoreductases catalyze oxidation-reduction reactions. Subclasses of this group include the dehydrogenases, oxidases, oxygenases, reductases, peroxidases, and hydroxylases. 

Note There is a systematic nomenclature for classifying the enzymes by function, as follows oxidoreductases involve oxidation-reduction reactions transferases involve the transfer of functional groups hydrolases involve hydrolysis reactions with water lyases involve the elimination of a group to form double bonds isomerases involve isomerization to a different structure but with the same chemical composition ligases involve the formation of a chemical bond simultaneously with ATP hydrolysis. There are in turn subclasses and sub-subclasses, and a subclass that... 

Enzymes have been named by adding the suffix -a.se to the name of the substrate or to a word or phrase describing their activity. Enzymes are classified according to reaction type. There are 6 major classes (with subclasses). Oxidoreductases catalyze oxidation-reduction reactions, the transfer of hydrogen atoms and electrons, for example dehydrogenation of lactate ... 

A large number of coenzymes are involved in oxidation-reduction reactions catalyzed by enzymes categorized as oxidoreductases. Some coenzymes, such as... 

The catalysis of oxidation-reduction reactions is carried out by a class of enzymes called oxidoreductases. A subclass of oxidore-ductases is given the common name dehydrogenases (such as lactate dehydrogenase), because they transfer hydrogen (hydrogen atoms or hydride atoms) from the substrate to an electron-accepting coenzyme, such as NAD. ... 

Oxidoreductases. Oxidation-reduction reactions are very common in biochemical pathways and are catalyzed by a broad class of enzymes called oxidoreductases. Whenever an oxidation-reduction reaction occurs, at least one substrate gains electrons and becomes reduced, and another substrate loses electrons and becomes oxidized. One subset of reactions is catalyzed by dehydrogenases, which accept and donate electrons in the form of hydride ions (H ) or hydrogen atoms. Usually an electron-transferring coenzyme, such as NAD /NADH, acts as an electron donor or acceptor (e.g., see Fig. 8.14 and Fig. 8.15). 

EC 1 Oxidoreductases catalyze oxidation-reduction reactions The substrate that is oxidized is regarded as hydrogen donor. The systematic name is based on donor acceptor oxidoreductase. The name dehydrogenase is recommended wherever possible and reductase is used as an alternative. Oxidase is used only when O2 is the acceptor. 

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