The formation of zymogen granules begins in the rough endoplasmic reticulum (RER), where digestive enzymes are synthesized as inactive precursors. These proteins are then transported to the Golgi apparatus for further modification and sorting. From the Golgi, they are packaged into secretory vesicles, which mature into zymogen granules. The granules are then transported to the apical region of the cell, ready for exocytosis upon stimulation.
