Explain the role of protein within plasma membranes.

Proteins within plasma membranes play the following roles.

• They provide structural support for the membrane. By various forms of molecular interactions, they help to anchor the phospholipid bimolecular layer.
• Transport: They assist in active transport of materials across the membrane by acting as channels through which especially hydrophilic materials pass.
• Cell recognition: In combination with carbohydrates, as glycoproteins, they act as recognition sites.
• Enzymatic activity: They act as enzymes, catalyzing many membrane-associated reactions.
• They act as energy transducers. For example, proteins of the election transport system in mitochondria.
• They act as election carriers in many redox reactions.
• Anchorage: Anchor cells to their neighboring cells