Diffusion of water from a dilute solution to a concentrated solution through a partiallypermeable membrane
Plant cells placed in water
Water moves into the cell by osmosis, causing the cell to expand
Plant cells placed in concentrated solution
Water moves out of the plant cell by osmosis, causing the cell to shrink
Investigating the effect of osmosis on plant tissue
1. Peel potato
2. Use cork board to produce potato cylinders of same diameter
3. Trim cylinders to same length (around 3cm)
4. Measure length and mass of each cylinder
5. Place cylinders in test tubes with different solutions (0.5M sugar, 2.5M sugar, distilled water)
6. Leave overnight to allow osmosis
7. Remove cylinders, gently roll on paper towel to remove surface moisture
8. Measure length and mass of cylinders again
Percentage change
Calculated as: (Change in value / Original value) x 100
Concentration of sugar solution
Affects percentage change in mass/length of potato cylinder
In water, potato cylinder gains mass as water moves in by osmosis. In concentrated sugar solution, cylinder loses mass as water moves out by osmosis. Where line crosses x-axis, no change in mass as concentration outside cell is same as inside.
