Endocytosis/Exocytosis
Endocytosis and exocytosis are other methods of active transport. They are excellent for moving large materials in and out of the cell.
In endocytosis, the cell forms a vesicle around the desired substance and engulfs it. If the substance engulfed is large, it is called phagocytosis. If the substance engulfed is small, then it is called pinocytosis. On the other hand, if a substance is being expelled from the cell, it is called exocytosis. This is essentially the reverse of endocytosis. A vesicle or vacuole fuses with the cell membrane and empties its contents out of the cell.
In endocytosis, the cell forms a vesicle around the desired substance and engulfs it. If the substance engulfed is large, it is called phagocytosis. If the substance engulfed is small, then it is called pinocytosis. On the other hand, if a substance is being expelled from the cell, it is called exocytosis. This is essentially the reverse of endocytosis. A vesicle or vacuole fuses with the cell membrane and empties its contents out of the cell.