What is an integral protein? What is its function?

An integral protein is a type of membrane protein that is permanently attached to the cell membrane. These proteins are embedded within the lipid bilayer, spanning across its entire width. Their structure is such that they have hydrophobic regions that interact with the hydrophobic interior of the lipid bilayer, anchoring them firmly in place.

The functions of integral proteins can vary widely depending on their specific structure and location within the cell membrane. Some common functions include:

Transport: Integral proteins can act as channels or carriers, facilitating the transport of specific molecules and ions across the membrane.

Receptor: They can serve as receptors for signaling molecules, such as hormones, allowing the cell to respond to external signals.

Enzymatic activity: Some integral proteins have enzymatic functions, catalyzing chemical reactions at the cell membrane.

Cell adhesion: Integral proteins can participate in cell-cell recognition and adhesion processes, helping cells to adhere to each other or to the extracellular matrix.

Structural support: They contribute to the structural integrity of the cell membrane and help maintain its shape.

Cellular recognition: Integral proteins may also play a role in identifying cells as belonging to a particular organism or tissue type, important in immune responses and tissue development.

Overall, integral proteins are crucial for the proper functioning and integrity of cell membranes, and they are involved in numerous essential biological processes.