Question

Pick up the correct statement regarding cell membrane from the choices given here.

• A. Proteins contribute to 60 to 70% of the cell membrane.
• B. Fluid mosaic model of cell membrane was proposed by Singer and Nicolson.
• C. Na${}^{+}$ and K${}^{+}$ ions move across cell membrane by passive transport.
• D. Lipids are arranged in a bilayer with polar heads towards the inner part.

Answer 1

The correct option is B Fluid mosaic model of cell membrane was proposed by Singer and Nicolson.

According to the fluid mosaic model of Singer and Nicolson, cell membranes are quasi-fluid in nature with a viscous lipid bilayer having proteins at places (mosaic) both on the surface and inside. The arrangement of lipids in bilayer is also called as a head parallel arrangement because the polar heads of both the lipid layers are oriented on the surface and hydrophilic tails are embedded inside the membrane. The membrane does not allow free movement of ions like sodium and potassium because they are water soluble solutes and the membrane is essentially a lipid bilayer. Special carrier proteins are present in the membrane for the transport of ions.

So, the correct answer is option B.