Aim: To view and examine the effect different concentrations of sucrose solution has on the movement of water across the cell membrane.
Hypothesis: That the potatoes will either increase or decrease in mass, due to the effect of the different concentrations. Osmosis will occur.
Apparatus:
* Fresh potatoes * Apple corer * Scalpel * Petri dishes X 10 * 50ml measuring cylinder * Distilled water * Paper towelling * Sucrose solutions: * 1.0M * 0.8M * 0.6M * 0.4M * 0.2M
Method:
Day 1 1. A cylinder was poked out of the potato with the apple corer and removed from the corer. That cylinder was then trimmed to make sure no skin was left. 2. The cylinder was sliced into 1mm thick pieces producing small cylinders. This was repeated until 20 pieces were obtained. 3. The 20 slices were placed into petri dishes and then weighed. The weights were recorded. This mass was known as the initial mass. (refer to results) 4. The different concentration of sucrose was then added into one petri dish, so in total there were 5 petri dishes with different concentration molars of sucrose, each containing the 20 slices of potato. 5. The petri dish was then covered and left to leave overnight in room temperature.
Day 2 1. The water was soaked up from the petri dish gently by using the paper towel. This was meant to be done gently enough to not press hard on the potatoes. 2. The potato slices were weighed again and the results were recorded. This mass was known as the final mass. 3. The changes in mass of the initial and final mass were recorded and are displayed in the results section. 4. The results from the different members doing the other concentrations were combined.
Results:
Sucrose solution (M) | initial (g) | after(g) | 0.2 | 2.653 | 2.812 | 0.4 | 3.61 | 2.906 | 0.6 | 3.443 | 2.836 | 0.8 | 2.363 | 3.129 | 1 | 4.517 | 3.713 |
Table 1: Table showing the