GLOSSARY

Exocytosis is the process by which a cell releases the contents of vesicles to the outside by fusing the vesicle membrane with the cell membrane.
The term is formed from the Greek exo, meaning “outside,” and cyto, meaning “cell,” and its opposite is endocytosis.

Mechanism and Function

A vesicle carrying cargo moves toward the cell membrane, docks with the help of specialized proteins, and the two membranes fuse so that the contents are emptied into the extracellular space.
Exocytosis is essential for secreting hormones, digestive enzymes, and neurotransmitters, as well as for adding new proteins and lipids to the cell membrane.
In many cells, the process is triggered by a sudden rise in intracellular