What is Exocytosis?

Exocytosis is the process by which a cell secretes large substances (such as digestive enzymes or hormones) that have been produced inside the cell.

Substances produced inside the cell are processed in an organelle called the Golgi aparatus. The Golgi Apparatus exists as a series of flattened sacs of membrane. Vesicles containing the processed substances 'pinch off' the membranous sacs of the Golgi. The vesicles travel towrds the cell membrne, where they fuse to the cell membrane and are release their contents outside the cell.