Question

How do neutral solutes move to cross the plasma membrane? Can the polar molecule also move across it in the same way? If not then how are these transported across the membrane?

Answer 1

1. Neutral solutes move across the plasma membrane by diffusion along the concentration gradient. 

2. Polar molecule cannot move across it in the same way. Polar molecules require a carrier protein of the membrane to facilitate their transport across the membrane.

3. Some ions or molecules are transported across the membrane against their concentration gradient, which is an energy dependent process. It is called active transport.