Diffusion

• Diffusion


  Net movement of particles from high concentration to low concentration area due to random movement
• Factors that affect diffusion are:

  1. Surface area
  2. Temperature
  3. Distance
  4. Concentration Gradient
• Temperature:


  The higher the temperature, the more kinetic energy the particles will have, so they will move and mix more quickly.
• Surface area:


  The greater the surface area, the faster the rate of diffusion.
• Examples of diffusion in a biological system:

  1. Leaf
  2. Lungs
  3. Liver
• In leafs

  
  

  Carbon dioxide diffuses into the leaf through stomata and dissolves in the moisture on the surface of the mesophyll cells

  
  

  Oxygen produced during photosynthesis diffuses out of the leaf through stomata

  
• In the lungs:

  
  

  Oxygen diffuses from alveoli into the bloodstream, while carbon dioxide diffuses from the bloodstream into the alveolii

  
• In the liver cells:

  
  

  Nutrients absorbed from the digestive system are transported to the bloodstream to the liver.

  
  

  Waste products produced are diffused from hepatocytes(cell in the liver) into the blood in the sinusoids( small blood vessel) for excretion

  
• Diffusion is essential for processes such as gas exchange in organisms, Nutrient uptake by cells, and waste removal from cells