Cell & Developmental Biology
Open Access

Exocytosis

Exocytosis is a form of active transport and bulk transport in which a cell transports molecules out of the cell  by secreting them through an energy-dependent process. Exocytosis and its counterpart, endocytosis are used by all cells because most chemical substances important to them are large polar molecules that cannot pass through the hydrophobic portion of the cell membrane by passive means. Exocytosis is in process a large amount of molecules are released thus making it a form of bulk transport.