PATHOLOGY

Detailed explanation-1: -Charged molecules, such as ions, are unable to diffuse through a phospholipid bilayer regardless of size; even H+ ions cannot cross a lipid bilayer by free diffusion.

Detailed explanation-2: -Charged atoms or molecules of any size cannot cross the cell membrane via simple diffusion as the charges are repelled by the hydrophobic tails in the interior of the phospholipid bilayer.

Detailed explanation-3: -This means that ions like sodium, potassium, calcium, and chloride cannot cross membranes to any significant degree by simple diffusion, and must instead be transported by specialized proteins (which we’ll discuss later).