EnzymeZymogen or proenzyme is a :

A zymogen, also known as a proenzyme, is an inactive precursor of an enzyme. It requires some kind of biochemical change (such as a hydrolysis reaction revealing the active site, or changing the configuration to reveal the active site) for it to become an active enzyme. This biochemical change is often enabled by a separate enzyme. The purpose of producing an enzyme in an inactive form is to prevent the enzyme from digesting the cells that produce them. This mechanism is used in many different types of enzymes, including digestive enzymes, clotting factors, and caspases.