Question

What is the similarity between simple diffusion and facilitated diffusion?



Both move molecules from lower concentration to higher concentration.



Both move molecules from higher concentration to lower concentration.



Both need energy.



Both need transport protein.

Answer 1

Diffusion is the movement of molecules across a semi-permeable membrane against a concentration gradient while facilitated diffusion is carrier mediated transport of molecules across a semi-permeable membrane. In facilitated diffusion, carrier proteins bind to the large molecules which cannot pass through the membrane and aide in their movement across it. Co transport of Na+ with sugars and amino acids is an example of facilitated diffusion that occurs in the body
hope this helps out

Answer 2

both of them go along with the concentration gradient, not against (for that you need to use energy i.e. ATP)