1. Observing Osmosis in Biological Systems
Plasmolysis

2. Some definitions
Osmosis: Passage of water from a region of low concentration of solute to a region of high concentration, across a semipermeable membrane
How is Osmosis different from Diffusion?

3. Isotonic: Same solute concentration
Hypotonic: Low solute concentration
Hypertonic: High solute concentration

4. Osmosis in plant cells

5. Osmosis in blood cells

6. Osmosis in plant cells - Plasmolysis

7. Experiment To observe plasmolysis in Rhoeo discolor

8. Protocol
Prepare sucrose dilutions from the 1M stock provided.
Peel off a thin layer of the leaf from the purple side ( purple layer only)
Put into the sucrose solution and wait for 20 minutes.
Place the layer on the microscope slide, place a coverslip and observe the cells under microscope.
Determine the number of plasmolysed cells in different concentrations of sucrose and estimate the isotonic concentration.

10. Sucrose concentration (M)
1 M sucrose (ml)
H2O (ml)
Number of plasmolysed cells
Total number of cells
% Plasmolysed
0.2
0.3
0.35
0.4
0.8
1.0