Adaptations for Rapid Transport (AQA A Level Biology)

Adaptations for Rapid Transport

• 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