Organic Cofactors as Coenzymes

A coenzyme is an organic molecule that can bind within enzymes that require its function to catalyze a biochemical reaction. Hence, coenzymes are organic cofactors that augment the diversity of reactions that otherwise would be more limited to chemical properties of side chain substituents from amino acid residues within protein enzymes. Coenzymes bind to apoenzymes to generate catalytically competent holoenzymes. With tight binding, coenzymes may be referred to as prosthetic groups; with loose binding, they may be called cosubstrates.