Cell performing pinocytosis
Introduction (what it is and meaning)
Pinocytosis is a process by which a cell eats macromolecules diluted in water. Generally, these macromolecules are proteins or polysaccharides. This process occurs in many cell types and functions as a complementary cell feeding system.
The word Pinocytosis derives from the Greek, and pins means to drink and quotes means cell.
Pinocytosis is one of two types of endocytosis processes, the other being phagocytosis (the cell eats large materials).
How Pinocytosis Occurs (Steps):
1º - Macromolecules dissolved in water are close to the plasma membrane of the cell.
2º - Invagination occurs in the plasma membrane, involving the macromolecules.
3º - The plasma membrane closes and forms, within the cytoplasm, the pinosome.
4º - Pinosomes are small vesicles (species of small bags) with the material ingested inside.
5º - Pinosomes can be digested by the cell (if they serve as food).