It is a thin layer that surrounds the cytoplasm and separates the cell from its environment . Its main function is to protect the cell from the outside and facilitate the exchange of materials. This membrane has pores or protein channels that connect the interior with the external environment, thanks to which the entry of substances useful for nutrition and the exit of those that are waste occurs. It is a semipermeable membrane. Its composition is characterized by the presence of a double layer of phospholipids with embedded proteins. It also has a fundamental role in other important processes such as cell adhesion and cellular communication that allows the exchange of information with other cells or tissues.
The cell membrane uses four transport methods :
- Passive osmosis and diffusion.
- Active transport.
Finally, the cell membrane helps fix the cytoskeleton , so it is vital in maintaining the shape of the cell and allowing it to form part of large arrangements of cells which give shape to tissues.