prozymogen
/prəʊˈzʌɪmədʒ(ə)n/Biochemistry
noun
A precursor of a zymogen (an inactive form of a (usually digestive) enzyme); prozymogen granule noun an intermediate stage in zymogen granule formation occurring prior to full condensation of the secretory material, characterized by the heterogeneous appearance of the vesicles.
Origin
Late 19th century. From pro- + zymogen.