Cofactor is a biological term used in describing a form of a non-protein chemical compound. It is highly required in the biological operation. It is in two types, the Coenzymes and Prosthetic groups.
While the Prosthetic groups are well connected to an enzyme, the coenzymes on the other hand are conected to an enzyme loosely.
Hence, it is TRUE that Cofactors for some enzymes are not considered prosthetic groups because they are loosely held during the course of the action
