Proteins are a very important part of the cell membrane. Basically they can be classified into two groups based on physical distribution. Integral proteins are embedded within the cell membrane and may in fact pass multiple times through the membrane. Peripheral proteins are loosely associated with membrane surfaces. Carbohydrate portions of glycoproteins and glycolipids are found on the external surface of the cell membrane where they are important parts of receptor molecules.
Receptors are necessary to cellular signalling, adhesion, and recognition.
Most proteins are fixed in place within the cell membrane by interactions with the cytoskeleton . However, some integral proteins can move about and sometimes will accumulate on one region of the membrane in a process called capping. The cell membrane is not static. It is remodeled by the addition of new membrane vesicles from the Golgi while removal takes place in the form of endocytotic, phagocytotic and pinocytotic vesicles being formed and then fused with lysozomes for processing. Membrane receptors and membrane are often conserved and recycled to the plasma membrane.