What is a membrane protein?

membrane proteins are proteins that are built between phospholipids that form a two -layer structure of cell membranes. The membrane protein performs specific tasks that are necessary for the proper functioning of the cell. These include the transport of molecules and ions to and out of the cell, the initial signaling pathway and make a cell recognizable for other cells. There are two main types of membrane proteins: peripheral and integral.

Peripheral membrane proteins are built on one side of the cell membrane, either on the outer surface or on the inner wall. Integral membrane proteins are built into the cell membrane and are projected into a cell or external environment. The integral membrane protein, which spans the entire cell membrane, from the outer surface of the cell to the inner surface of the cell, is called transmembrane protein.

The peripheral membrane protein, which is located on the outer surface of the cell membrane, interacts with the molecules of That is released by other cells. MediumThe ICV of the process called cell signaling can communicate one cell with another cell of the release of chemical messengers. The messences are recognized by external proteins of the peripheral membrane.

Peripheral membrane proteins, which are located on the inner surface of the cell membrane, provide the foundation for scaffolding cells. These include cytoskeletal proteins of actin and spectrins. The enzyme called Protein Kinase C is another internal protein of the peripheral membrane. It initiates the signaling pathway inside the cell.

Peripheral membrane proteins do not interact with the non -polar area of ​​the cell membrane. Instead, they are bound to the cell membrane through interactions between the polar areas of phospholipids and the polar regions of the protein. Many peripheral membrane proteins also bind to integral membrane proteins.

Integrual membrane proteins transport molecules from the external environment to the interior of the cell. Some can freely transportovate molecules while others require energy to transport molecules. The membrane integral proteins also serve as receptors for specific molecules and as enzymes for specific metabolic pathways.

The amino acid chain of integral membrane protein can once pass through the cell membrane or weaving several times and out of the cell membrane. They contain non -polar side chains that allow them to interact with phospholipid fatty acid chains. This interaction holds the integral membrane protein firmly to the cell membrane. Integral membrane proteins also have a polar area that extends into a cell or external environment.