Movement in & out of cells

DIFFUSION

Diffusion is defined as the net movement of molecules from a region of their higher concentration to a region of their lower concentration down a concentration gradient until equilibrium is reached.

Factors affecting rate of diffusion are:

• temperture-  with increasing temperature, molecules gain more kinetic energy and hence they move faster. Therefore the rate of diffusion increases.                                            
  
• size/mass of molecules-  the smaller the molecules, the faster is the rate of diffusion.
• surface area-   with increasing surface area, the rate of diffusion increases.
• concentration gradient-   the higher the concentration, the faster is the rate of diffusion.

Importance of diffusion to living organisms are:

• gaseous exchange across…