What Is a Transmembrane Protein?
A transmembrane protein is a protein which spans the entire length of the cell membrane. It is embedded between the phospholipids, providing a channel through which molecules and ions can pass into the cell. Transmembrane proteins also facilitate communication between cells by interacting with chemical messengers. Many biological processes, such as the metabolism of glucose and the production of fatty acids, are triggered after a particular transmembrane protein is activated. The insulin receptor is an example of a transmembrane protein which interacts with a chemical messenger, namely insulin. The receptor acts as a target on the surface of the cell for the insulin molecule. After the molecule docks with the receptor, the receptor typically releases chemicals that cause the movement of a glucose transporter to the surface of the cell. This allows the cell to absorb large amounts of glucose from the external environment, leading to glucose metabolism and eventually energy production.
