Cytosis
![Entry of material into the nucleus through endocytosis. Endocytosis: The membrane of the cell invaginates, creating a small circular pit that is taken into the cytosol of the cell. This circular membrane coated pit is a vescile that is transported to the lysosome of the cell to be degraded by enzymes.](/Images/godic/202501/07/Cell_nucleus3449.jpg")
![Mechanism of clathrin-dependent endocytosis. Clathrin-coated pits in endocytosis: The membrane of the cell invaginates using the protein clathrin. The clathrin uses actin to pull together the sides of the plasma membrane and form a vesicle inside the cellular cytosol.](/Images/godic/202501/07/Itrafig23449.jpg")
Cytosis (cyto- + -osis) is a transport mechanism for the movement of large quantities of molecules into and out of cells.
There are three main types of cytosis: endocytosis (into the cell), exocytosis (out of the cell), and transcytosis (through the cell, in and out).