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

Explanation

Neutral molecules e.g. non-electrolytes like copper sulphate molecules move along concentration gradient by simple diffusion. The polar molecules cannot pass across plasma membrane by simple diffusion because of bipolar nature of lipid bilayer. The polar molecules pass through plasma membrane by the process of facilitated diffusion which is associated with certain carrier protein molecules, called permeases, and occurs through specific channels of the carrier molecules.