Final answer:
Peripheral proteins are membrane-associated proteins that attach non-covalently to the cell membrane and can easily be removed, often playing roles in signaling and receptor activities.
Step-by-step explanation:
​Peripheral proteins are the type of membrane proteins that are non-covalently bonded to the polar head groups of the lipid bilayer and/or to an integral membrane protein. They are often associated with functions such as cell signaling, ion channel activity, and acting as transmembrane receptors. Unlike integral proteins that span across the lipid bilayer, peripheral proteins may simply attach to the surface of the cell membrane through non-covalent interactions like hydrogen bonding and electrostatic forces, and they are known for being temporarily associated with the membrane, making them easier to remove.
These membrane-associated proteins do not require cellular energy to be attached or removed from the cell membrane. Their association with integral proteins or the lipid bilayer's polar head groups allows them to participate in a variety of cellular activities, including holding cells in place and contributing to the structure of cells and tissues. Peripheral membrane proteins are generally hydrophilic due to their ability to interact with the cell's external environments.