Osmotic Pressure
OBJECTIVE:
To describe the effect of water gain or loss in animal and plant cells.
INTRODUCTION:
Osmosis is the tendency of water to flow from a hypotonic solution (low concertration of dissolved substances) to hypertonic solution ( higher concerntration of dissolved substances) across a semipermeable membrane.
Osmosis occurs when different concentrations of water are separated by a differentially permeable membrane. One example of a differentially permeable membrane within a living cell is the plasma membrane.
• Hypotonic :
➢ Having a lesser osmotic pressure in a fluid compared to another fluid, as in a ‘hypotonic solution’ – compare: hypertonic and isotonic
• Hypertonic:
➢ Having a higher osmotic pressure in a fluid relative to another fluid.
• Isotonic:
➢ Having the same (or equal) osmotic pressure and same water potential since the two solutions have an equal concentration of water molecules.
MATERIALS:
1. Potato slices 2. Elodea leaf/ onion scales 3. Razor blades 4. Digital balance /string /ruler 5. Varying molar of sucrose solutions (0.01 M, 0.02 M, 0.05 M, 0.1 M, 0.3 M, 0.5 M) 6. Tissue papers 7. Test tubes 8. Watch glass 9. Forceps
PROCEDURE:
Task 1: The effect of osmosis in potato cells
1. The potato was cut in to 3 slices for each solution and placed in 7 Petri- dishes.
2. The potatoes were weighed for each slice and recorded the weight in the table.
3. 2 ml of sucrose solutions was added in each of 7 Petri-dishes contain the following:
a. Petri-dish 1: 0.01M b. Petri-dish 2: 0.02M c. Petri-dish 3: 0.05M d. Petri-dish 4: 0.1M e. Petri-dish 5: 0.3M f. Petri-dish 6: 0.5M g. Petri-dish 7: Distilled water
4. The potato is left for about 20 minutes.
5. After 20 minutes,
To describe the effect of water gain or loss in animal and plant cells.
INTRODUCTION:
Osmosis is the tendency of water to flow from a hypotonic solution (low concertration of dissolved substances) to hypertonic solution ( higher concerntration of dissolved substances) across a semipermeable membrane.
Osmosis occurs when different concentrations of water are separated by a differentially permeable membrane. One example of a differentially permeable membrane within a living cell is the plasma membrane.
• Hypotonic :
➢ Having a lesser osmotic pressure in a fluid compared to another fluid, as in a ‘hypotonic solution’ – compare: hypertonic and isotonic
• Hypertonic:
➢ Having a higher osmotic pressure in a fluid relative to another fluid.
• Isotonic:
➢ Having the same (or equal) osmotic pressure and same water potential since the two solutions have an equal concentration of water molecules.
MATERIALS:
1. Potato slices 2. Elodea leaf/ onion scales 3. Razor blades 4. Digital balance /string /ruler 5. Varying molar of sucrose solutions (0.01 M, 0.02 M, 0.05 M, 0.1 M, 0.3 M, 0.5 M) 6. Tissue papers 7. Test tubes 8. Watch glass 9. Forceps
PROCEDURE:
Task 1: The effect of osmosis in potato cells
1. The potato was cut in to 3 slices for each solution and placed in 7 Petri- dishes.
2. The potatoes were weighed for each slice and recorded the weight in the table.
3. 2 ml of sucrose solutions was added in each of 7 Petri-dishes contain the following:
a. Petri-dish 1: 0.01M b. Petri-dish 2: 0.02M c. Petri-dish 3: 0.05M d. Petri-dish 4: 0.1M e. Petri-dish 5: 0.3M f. Petri-dish 6: 0.5M g. Petri-dish 7: Distilled water
4. The potato is left for about 20 minutes.
5. After 20 minutes,