Biology AT1 - Osmosis
Potatoes are the living tubers of the potato plant. They are the stores of carbohydrates that would normally be used to produce new potato plants in the spring. When potato tissue is put into sugar solution, osmosis occurs between the calls and the solution.
In my experiment, I will first, cut fifteen lengths of potato about 3cm long, using a borer, and then weigh them. I will use this many because I have chosen to use five different sugar solutions for the experiment and to make it more fair then there will be three strips of potato in each solution. The points of the graph of result I will make will be from the averages of percentage weight change of each strip. I will fill five test tubes with 10ml of each solution, one will be distilled water, and then the four others will be different concentrations of sugar solution, ranging from 0.2M TO 0.9M. The five test tubes will have a bung in the top to stop any solution evaporating or the air to in any other way affect the experiment. The test tubes will then be left over night so osmosis can occur fully. After 24 hours, I will take each potato strip and re-weigh them all, recording these results. I predict that osmosis will not occur in the distilled water and this will be a control. I also predict that the more concentrated the sugar solution is, the more osmosis will occur, making the potato lightest when the sugar solution is strongest, as more water has come from the potato into the solution to even up the level of concentration inside the solution and the potato. Preliminary work has been done showing that osmosis does occur in potato tissue, but not measuring weight. In that experiment, the droop of a longer potato tissue sample was measured.
Potatoes are the living tubers of the potato plant. They are the stores of carbohydrates that would normally be used to produce new potato plants in the spring. When potato tissue is put into sugar solution, osmosis occurs between the calls and the solution.
In my experiment, I will first, cut fifteen lengths of potato about 3cm long, using a borer, and then weigh them. I will use this many because I have chosen to use five different sugar solutions for the experiment and to make it more fair then there will be three strips of potato in each solution. The points of the graph of result I will make will be from the averages of percentage weight change of each strip. I will fill five test tubes with 10ml of each solution, one will be distilled water, and then the four others will be different concentrations of sugar solution, ranging from 0.2M TO 0.9M. The five test tubes will have a bung in the top to stop any solution evaporating or the air to in any other way affect the experiment. The test tubes will then be left over night so osmosis can occur fully. After 24 hours, I will take each potato strip and re-weigh them all, recording these results. I predict that osmosis will not occur in the distilled water and this will be a control. I also predict that the more concentrated the sugar solution is, the more osmosis will occur, making the potato lightest when the sugar solution is strongest, as more water has come from the potato into the solution to even up the level of concentration inside the solution and the potato. Preliminary work has been done showing that osmosis does occur in potato tissue, but not measuring weight. In that experiment, the droop of a longer potato tissue sample was measured.
