proenzyme

/proʊˈɛnzaɪm/
noun
  1. An inactive precursor of an enzyme that becomes active after a chemical change.
    • The body stores proenzymes in the pancreas to prevent digestion of the organ itself.
    • When a proenzyme is cleaved by another enzyme, it becomes fully functional.
    • Scientists study proenzymes to understand how cells control important chemical reactions.