Effects of osmosis on plant tissue

• when a plant cell is placed in water, water moves into the cell by osmosis and the cell expands
• when a plant cell is placed into into a concentrated solution water moves out of the cell by osmosis and it shrinks
• 1

  peel the potato -the skin can affect osmosis
• 2

  use a cork borer to produce 3 cylinders of potato - makes them the same diameter
• 3

  use scalpel to trim them to the same length (around 3cm)
• 4


  measure their lengths with a ruler, mass with a balance
• 5

  place each cylinder into a test tube

  • first has 10cm cubed of a 0.5 molar sugar concentration
  • second has a 10cm cubed of 0.25 molar sugar solution
  • third has 10cm cubed distilled water
• 6


  leave overnight so osmosis can take place
• 7


  remove them from the test tubes and pat dry with paper towel to remove surface moisture
• 8

  measure mass and length again
• percentage change = change in value/original value X 100
• in water the potato gains mass as water moves in by osmosis
• in concentrated sugar solutions the potato decreased in mass as water moves out by osmosis
• when the concentration in the cell is the same as the concentration outside the cell no overall osmosis takes places