• The rate at which?diffusion?(including both?simple?diffusion and?facilitated?diffusion) occurs across external and internal cell membranes?varies
• Some cells are?adapted?for?rapid transport?(diffusion) of molecules?across?their internal or external?membranes
• The?rate of diffusion?depends on several?factors. These include:
  • Temperature
  • The?surface area?of the exchange surface
  • The?concentration gradient?across the exchange surface
  • The?thickness?of the exchange surface

   

Simple diffusion

The rate of simple diffusion depends on three main factors:

Facilitated Diffusion

The rate of facilitated diffusion depends on two main factors