When proteins help transport molecules in and out of the cell, it is called as facilitated diffusion. Facilitated diffusion is also popularly known as facilitated transport. The transporter that is the protein helps in transporting or the movement of molecules or ions across the plasma membrane. The proteins that transport these molecules are termed as the facilitative transporters or uniporters such as the amino acid transporters, facilitative urea transporters and a lot more. These transporters also important functions as an organism or a cell.