What is the cell membrane composed of?

Smaller,lipid-soluble molecules diffuse faster through the cell membrane,but the movement of hydrophilic substances is facilitated by certain transporters which are chemically $.......$

Membrane proteins are held in the bilayer mainly by

Which one of the following is not present in the plasma membrane?

In the cell membrane,carbohydrates are attached to $...........$.

According to Robertson,the thickness of the lipid zone in the cell membrane ranges from