Facilitated Diffusion

What kinds of molecules use facilitated diffusion

Large, polar molecules and ions that can’t cross the phospholipid bilayer on their own

Does facilitated diffusion require energy (ATP)

No it’s a passive process that moves materials down their concentration gradient

What are the two main types of transport proteins used in facilitated diffusion

Channel proteins and carrier proteins

What are channel proteins

Integral lipoproteins that form a hydrophilic pore allowing ions to pass across the membrane

What kinds of substances move through channel protein

Ions and small polar molecules

Are channel proteins selective

yes they are ion-selective and can be gated to open or close in response to signals (like voltage or chemicals)

Do channel proteins move molecules against the gradient

No they only allow movement along a concentration gradient (passive transport only)

what type of protein is this

Channel Proteins

Carrier Protein