Factors Affecting Diffusion
Biology: Cambridge International GCSE Supplement, topic 3.1.2
Factors Affecting Diffusion
The rate of diffusion can speed up or slow down based on the following factors:
Concentration gradient
- The concentration gradient is linked to the difference in concentration between two areas.
- The bigger the difference in concentration between two areas, the greater the concentration gradient and the faster the rate of diffusion.
Temperature
- The higher the temperature, the faster the rate of diffusion.
Membrane surface area
- The larger the surface area of the membrane that a substance is diffusing through (e.g. the membrane around a cell), the faster the rate of diffusion.
Distance
- The greater the distance a substance has to diffuse across, the more time taken.
- For example, a thicker membrane creates a larger distance, so diffusion across it will take longer.
Test yourself on Factors Affecting Diffusion
What would happen to the rate of diffusion if the concentration got steeper and the temperature rose?