Answer:
A cofactor is a not proteic substance that is required to an enzyme activity. Cofactors can either be organic compunds, like vitamins, or inorganic compounds, like the metallic elements, iron, zinc, magnesium, cooper, among others. If the cofactor is removed from a complete enzyme (holoenzyme), the protein component (apoenzyme) no longer has catalytic activity.
In some enzymes the cofactors act for the substrate binding to the active site. In other, like dehydrogenases, which transfer electrons from the substrate to an electron carrier, the carrier used depends on the reaction taking place. Common electron acceptors used by this subclass are NAD+, FAD, and NADP+. Electron carriers are reduced in this process and considered oxidizers of the substrate. Electron carriers are coenzymes that are often referred to as redox cofactors.
Explanation: