Final answer:
Integral proteins have vital roles in the cellular membrane, including transporting molecules, acting as receptors, facilitating cell recognition, and providing structural support. They are embedded in the membrane and can span it or be attached on one side, enabling them to interact with different substances and contribute to the cell's selective permeability and communication.
Step-by-step explanation:
The function of integral proteins is to manage various vital processes in the plasma membrane of cells. These proteins are permanently embedded within the cell membrane and perform crucial functions such as transporting molecules, acting as cell receptors, and facilitating cell recognition processes. Integral proteins can either span the entire membrane, forming channels or pores for substances to pass through, or be partially embedded on one side of the membrane.
For example, some integral proteins are responsible for facilitating the movement of ions or molecules across the cell membrane, contributing to the selective permeability of the membrane. They can consist of alpha-helices or beta-sheets, which help them to span the membrane and interact with hydrophobic and hydrophilic regions appropriately. Integral proteins also play a critical role in cell signaling, where the receptor-ligand interactions can induce a chemical reaction within the cell, such as the binding of dopamine to its receptor on nerve cells.
In addition, integral membrane proteins can serve dual functions, acting as both receptors and ion channels, while helping to anchor the cell in place and giving cells and tissues structure. This diverse range of functions ensures that the cell can interact with its environment effectively and maintain homeostasis.