Gas exchange in simple unicellular organisms

Gas exchange in simple unicellular organisms

1. The cell membrane is the site of gas exchange

2. Example of a unicellular org

   • Amoeba

3. Where do they live

   • Live in water and diffusion of gases occurs over the whole body surface

4. They have:

   • A large surface area to volume ratio
   • Their membranes are thin and moist
   • Short diffusion pathways
   • Are small and need to be small in order for diffusion to be efficient

5. How they become larger

   • Aggregate their cells together

6. The process of diffusion is slow

   • WHY?
     • Materials need to be exchanged between different organs as well as the environment