Image Credit: Explode / Shutterstock.com What are coenzymes? A coenzyme is defined as an organic molecule that binds to the active sites of certain enzymes to assist in the catalysis of a. They need a coenzyme to carry a chemical group, donate or accept electrons, or otherwise participate in the reaction’s chemistry. Most coenzymes are built from vitamins or nucleotides, which is one reason dietary deficiencies can ripple through so many bodily functions at once. A coenzyme is a molecule required by a particular enzyme to carry out the catalysis of a chemical reaction. Learn more about coenzyme types, importance, and examples. A coenzyme is an organic non-protein compound that binds with an enzyme to catalyze a reaction. Coenzymes are often broadly called cofactors, but they are chemically different. The meaning of COENZYME is a thermostable nonprotein compound that forms the active portion of an enzyme system after combination with an apoenzyme. coenzyme, Any of a number of freely diffusing organic compounds that function as cofactor s with enzyme s in promoting a variety of metabolic reactions. Coenzyme A (CoA, SHCoA, CoASH) is a coenzyme, notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the citric acid cycle. Learn about CoQ10 (coenzyme Q10) supplements, including health benefits, recommended dosage guidelines, potential side effects, and drug interactions. You can think of a coenzyme or cosubstrate as a helper molecule that aids an enzyme in catalyzing a chemical reaction. A coenzyme requires the presence of an enzyme in order to function. It is not active on its own. While enzymes are proteins, coenzymes are small, nonprotein molecules. A cofactor can be either an inorganic ion, such as Zn 2+, or a small organic molecule, called a coenzyme. A coenzyme is not a catalyst but is a reactant that undergoes chemical change during the reaction and requires an additional step to return to its initial state.