What are the limitations of facilitated diffusion, and what types of molecules can and can’t be transported this way?

Question

Please answer ASAP. What are the limitations of facilitated diffusion, and what types of molecules can and can’t be transported this way?

Answer 1

Facilitated diffusion is faster than simple diffusion. Facilitated diffusion requires transport proteins but not energy. Examples of facilitated diffusion include the transport of water, specific ions and hydrophilic small molecules down their concentration or electric potential gradient

it is a form of passive transport, so a molecules that require active transport cannot be transported this way. For example, if you need to move ions against the concentration gradient...