Facilitated diffusion

Common card · No. 355000

Facilitated diffusion (also known as facilitated transport or passive-mediated transport) is the process of spontaneous passive transport (as opposed to active transport) of molecules or ions across a biological membrane via specific transmembrane integral proteins. Being passive, facilitated transport does not directly require chemical energy from ATP hydrolysis in the transport step itself; rather, molecules and ions move down their concentration gradient according to the principles of diffusion. Facilitated diffusion differs from simple diffusion in several ways: The transport relies on molecular binding between the cargo and the membrane-embedded channel or carrier protein. The rate of facilitated diffusion is saturable with respect to the concentration difference between the two phases; unlike free diffusion which is linear in the concentration difference. The temperature dependence of facilitated transport is substantially different due to the presence of an activated binding event...

Read on Wikipedia · Image Kjaray, CC BY-SA 4.0