Exoenzyme

An exoenzyme, or extracellular enzyme, is an enzyme that is secreted by a cell and that works outside that cell. It is usually used for breaking up large molecules that would not be able to enter the cell otherwise. The opposite of an exoenzyme is called an endoenzyme. It is an enzyme microorganisms excrete into the environment. It is an enzyme that acts outside the cell.

This term is also often used to refer to the hydrolytic digestive enzymes secreted by fungi.