Transport

• Osmosis

  The net movement of water particles form a region of high water potential to an area of low water potential across a selectively permeable membrane.
• Diffusion

  The net movement of particles from and area of high concentration to an area of low concentration
• Active Transport

  The movement of molecules from and area of low concentration to an area of high concentration against the concentration gradient using ATP
• Co-transport

  The movement of molecules across a membrane in both directions
• Isotonic

  A solution with the same water potential as a cell
• Hypertonic

  A solution with lower water potential than a cell
• Hypotonic

  A solution with a higher water potential than a cell
• Places active transport is used

  • Minerals from soil to roots
  • Amino acid uptake in fungi
  • Neurons
• Facilitated Diffusion (Channel)

  • Takes place through permanently open channels in membrane
  • Channels made with hydrophilic amino acids and water
  • Other molecules that are too large need modified carrier proteins
• Facilitated Diffusion (Carrier)

  • Molecule binds causing change in proteins shape
  • This allows molecule through to other side of membrane
• Fick‘s Law - rate of diffusion is a direction across an exchange surface is:

  • Directly proportional to surface area
  • Directly proportional to concentration gradient
  • Inversely proportional to length of diffusion path