Final answer:
Peripheral membrane proteins are located on the exterior or cytoplasmic side of the cell membrane, often involved in cell signaling, ion channels, and transmembrane receptors, and play crucial roles in substance transport and enzymatic functions.
Step-by-step explanation:
The peripheral membrane proteins are located outside the bilayer on either the extracellular or cytoplasmic side and are covalently linked to membrane lipids situated within the bilayer.
Peripheral proteins are found only on one side of the membrane, either on the cytoplasmic side or the outside. They are not embedded within the phospholipids, but are generally attached to proteins on the outside membrane layer. While some are temporarily associated with the membrane, involved in cell signaling, and can be easily removed, others are attached to integral membrane proteins or can adhere to a portion of the lipid bilayer by themselves.
These proteins are often associated with ion channels and transmembrane receptors, performing specific functions such as acting as digestive enzymes on the surface of intestinal cells or regulating the transport of substances like ions and nutrients across the cell membrane.