Are phagocytosis and pinocytosis also exocytosis, or what is considered exocytosis?
Answer Thanks for using AllExperts, Greg. Pinocytosis and phagocytosis are forms of endocytosis: they are forms of cellular transport in which the cell engulfs material with its cell membrane to bring that material into the cell. Specifically, in phagocytosis the cell surrounds something with its membrane and closes off that indentation to form a phagosome, or food vacuole; this process is specific to undigested solid material. Pinocytosis is the pinching off of small sections of cellular membrane to form vacuoles and is generally used to transport extracellular liquid or some pre-digested material. Exocytosis is the reverse process, by which cells expel material through their cellular membrane. Phagocytosis and pinocytosis are therefore not forms of exocytosis.
