Oxidoreductase is an enzyme that catalyzes oxidation and reduction.Where oxidase（oxidase；oxydase）Can catalyze the oxidation of substances by oxygen, dehydrogenase（dehydrogenase）It can catalyze the removal of hydrogen from material molecules.It mainly exists in cells.
The oxidoreductase catalyzes the oxidation or reduction of the substrate, and the reaction requires an electron donor or a receptor.Many oxidoreductases in the organism need coenzyme NAD (nicotinamide adenine dinucleotide) or NADP (nicotinamide adenine dinucleotide photo) and FAD (fluorescent adenine dinucleotide) orFMN（flavin mononucleotide）。Of course, some enzymes do not need coenzymes or cofactors, and directly use oxygen as the electron transmitter, such as glucose oxidase.
One of the major groups in enzyme classification.The first digit of the enzyme number of the IUB Enzyme Naming Committee is indicated by I.The types of oxidation-reduction reactions in organisms include the movement (transmission) of hydrogen atom pairs, the movement of electrons, or the addition of oxygen atoms.It can be considered that hydrogen atom (H) is hydrogen ion (H+）+Electronic, and equivalent to electronic;It acts as a reducing agent.A substance that gives electrons or H to oxidize itself is called an electron donor or a hydrogen donor.The substance that acts as an oxidant and receives electrons or hydrogen and is itself reduced is called an electron receptor or a hydrogen receptor.The oxidoreductase is specific for one or both of the electron donors and receptors.They are classified according to their specificity.
As shown in Figure 1, ketone reductase reduces ketones to chiral alcohols, NAD (NADP) transfers electrons in the reaction, and the regeneration of coenzyme NADH (NADPH) passesGlucose dehydrogenaseIt catalyzes glucose production.As the first enterprise in the world to industrially produce NAD (H) and NADP (H) by enzymatic method.
Figure 1 Schematic Diagram of NAD (P) -- NAD (P) H Cycle
Donor classification
Announce
edit
As donors, they are classified as: (1) CH OH group (product C=O), (2) aldehyde or ketone group (carboxyl), (3) CH-CH group (C=C), (4) CH-NH2 (C=NH, and then C=O+NH3), (5) CH-NH (C=N), (6)NADHorNADPH（NAD+Or NADP+）, (7) nitrogenous compounds, (8) sulfur-containing groups, (9) heme, (10) diphenol (quinone) (the number is the second digit of the enzyme number).
Receptor classification
Announce
edit
According to receptors: (1) NAD (NADP), (2) cytochrome, (3) oxygen, (4) disulfide bond, (5) quinone, (6) nitrogenous compound, (7) iron sulfur protein, 99 and others (the number represents the third digit of enzyme number).
Oxygen receptor is called oxidase.There are also enzymes that decarboxylate with oxidation, or the generated carboxylic acid and phosphoric acid combine to form mixed acid anhydrous compounds.They are all included in oxidoreductases.Also classified ashydrogen peroxidePeroxidase and catalase (enzyme number: position 2, 11) as receptors, hydrogenase (position 2: 12) and oxygenase (position 2, 13, 14) with hydrogen as donor.The oxidation-reduction reaction used in organisms has a large energy difference. Because coenzymes with intermediate oxidation-reduction potential and pigments are used as intermediates, most oxidation-reduction enzymes involve coenzymes and pigments.Most enzymes combine with coenzymes to form complex enzymes, which constitute the electron transfer system (chain) from the matrix to the final electron receptor.Pyridase, luteinase, heme enzyme, and quinone related enzymes are all examples of this aspect. Because there are significant differences in absorption spectra between all oxidation and reduction types, their reactions can be easily measured.On the other hand, it is also highly reactive and has nothing to do with the internal functions of the organism, especially those that can obviously react with oxygen and other receptors.
