What is required for facilitated diffusion to occur?

Facilitated diffusion requires specific transport proteins because this process is designed to help certain molecules, which may not easily pass through the lipid bilayer of the cell membrane, move across it more efficiently. These transport proteins, which can be either channel proteins or carrier proteins, provide a pathway for substances such as glucose or ions to go from an area of higher concentration to one of lower concentration without the need for energy input.

This is fundamentally different from other forms of transport such as active transport, which does require energy in the form of ATP to move substances against their concentration gradient. The use of energy or the condition of the cell membrane itself does not play a role in facilitated diffusion; rather, it is specifically the presence of the appropriate transport proteins that enables this type of passive transport to occur. Additionally, temperature can affect the rate of diffusion, but it is not a requirement for the process itself to take place.