DIFFUSION

• Simple diffusion definition 


  The net movement of molecules or ions from an area of high concentration to an area of low concentration down a concentration gradient until evenly distributed
• Is simple diffusion an active or passive process?

  Passive
• What is facilitated diffusion?


  movement of molecules or ions through channel or carrier proteins
• Is facilitated diffusion an active or passive process?

  Passive
• How does a channel protein perform facilitated diffusion?

  Ions bind to protein causing it to change shape in a way that closes it on one side and open to the other side
• How does a carrier protein perform facilitated diffusion?

  When a molecule (e.g. glucose) that is specific to the protein is present it binds with the protein causing it to change shape in such a way that the molecule is released to the other side of the membrane (down the concentration gradient)