osmosis

• the net movement of water particles from a higher water potential to a lower water potential across a partially permeable membrane
• pure water has a water potential of 0
• impure water has a negative value
• isotonic is when there is no osmosis and the concentration of the solution is the same inside and outside the cell
• hyotonic is when there is a higher water potential inside the cell than outside the cell
• hypertonic is when there is a higher concentration of solutes outside the cell than inside the cell
• the steeper the water potential gradient the faster the rate of osmosis
• the thinner the exchange surface the faster the rate of osmosis
• the larger the surface are the faster the rate of osmosis
• 1. line up 5 test tubes in a rack
  2. add 10 cm of the initial 2M sucrose solution to the first test tube and 5 cm of water to the other test tubes
  3. draw 5 cm of the solution from the first tube and add it to the second tube and mix
  4. repeat this process
• 1. cut potatoes into identically sized chips about 1 cm in diameter
  2. place one group into each of the sucrose solutions and leave the chips in the solution for 20 minutes
  3. remove the chips and pat dry with a paper towel
  4. weigh each group and calculate the percentage change in mass for each group