State the characteristics of facilitated diffusion.

(N/A) Facilitated diffusion is sensitive to inhibitors that react with the side chains of proteins.
Proteins in the membrane provide sites for molecules to cross the membrane.
Some channels are always open,while others are controlled or gated.
Some channels are large,allowing a variety of molecules to cross.
Porins are proteins that form large pores in the outer membranes of plastids,mitochondria,and some bacteria,allowing molecules up to the size of small proteins to pass through.
In facilitated diffusion,the transport protein binds to the extracellular molecule and then releases it into the cell.
An example is the water channel,which is made up of eight different types of aquaporins.