noun, plural: oxidoreductase
An enzyme is a catalyst or a chemical produced by cells to speed up a biochemical reaction. It is usually a protein molecule with a characteristic sequence of amino acids that fold to produce a specific three-dimensional structure, which gives the molecule unique properties. Other molecule with catalytic activity is ribozyme, an enzyme made of RNA rather than protein. Enzymes may be classified and named according to the reaction they catalyze: (1) oxidoreductases, (2) transferases, (3) lyases, (4) isomerases, and (6) ligases.
Oxidoreductases, or EC 1, catalyze oxidation/reduction reactions. They speed up the transfer of electrons from an electron donor to an electron acceptor. This group usually use cofactors, NADP or NAD+. There are different subclasses that comprise this group. One of them is the EC1.1 that includes oxireductases acting on the CH-OH group of donors. Examples are alcohol oxidoreductases and aldo-keto reductases. Another subclass is the EC1.3, which includes oxidoreductases that act on the CH-CH group of donors. CH–CH oxidoreductases are an example of EC1.3. They convert single bonds and double bonds between two carbon atoms.