Question

What is the percentage of intrinsic proteins in the total proteins of plasma membrane?

• A. 70%
• B. 20%
• C. 10%
• D. 90%

Answer 1

The correct option is A 70%

The plasma membrane or cell membrane is the outer covering of all cells but in a plant cell, it is present below the cell wall. It is mainly composed of phospholipid bilayer structure with the embedded proteins. The membrane proteins are extrinsic (on the surface of the membrane) and intrinsic (across the membrane i.e., cross the bilipid layer). About 70% of the proteins of the plasma membrane are intrinsic proteins. The intrinsic proteins, as their name implies, are firmly embedded in the phospholipid bilayer. Almost all intrinsic proteins contain special amino acid sequences.