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Cofactors are metal ions. These ions commonly provide a needed change within an active site.  Many enzymes use metal ions to change a non-functioning active site to a functioning one. In these enzymes, the attachment of a cofactor causes a shape change in the protein that allows it to combine with its substrate. The cofactors [...]

Most of the enzymes are made up of two proteins, a coenzyme and apoenzyme. The coenzyme or organic prosthetic group is the non protein part of the enzyme and protein part is known as apoenzyme. Both coenzyme and apoenzyme make a true or active enzyme.