Facilitated Transport (Facilitated Diffusion)
Facilitated transport is another form of passive transport. It uses carrier proteins embedded on the surface of the cell to transport specific ions/molecules into and out of the cell. Unlike diffusion or osmosis, molecules being moved through carrier proteins do not have to pass directly through the cell membrane. This allows a much greater variety of materials to be transported. However, facilitated transport can only move molecules along the concentration gradient. Examples of molecules entering/leaving the cell using this method include glucose and amino acids.
Say that we put a solution with a high concentration of amino acids (enclosed by a sack of artificial membrane) inside a beaker of water, you will soon notice that amino acids are "escaping" from the membrane. This is because they are being transported by carrier proteins along the concentration gradient.
Say that we put a solution with a high concentration of amino acids (enclosed by a sack of artificial membrane) inside a beaker of water, you will soon notice that amino acids are "escaping" from the membrane. This is because they are being transported by carrier proteins along the concentration gradient.