Zymogens are enzyme precursors. They are also referred to as proenzymes. They are inactive in a way that they are not functional until a biochemical change occurs. A biochemical change is required to activate it.

Are zymogens inactive?

A zymogen (/ˈzaɪmədʒən, -moʊ-/), also called a proenzyme (/ˌproʊˈɛnzaɪm/), is an inactive precursor of an enzyme. The pancreas secretes zymogens partly to prevent the enzymes from digesting proteins in the cells in which they are synthesised. ...

How are zymogens activated?

How are they activated ? Zymogens can be activated by proteases that cut the amino acid bonds. They can also be activated by the environment and become autocatalytic. Autocatalysis is self-activation and happens when something in the environment allows the zymogen to cut its own chemical bonds.