Investigate the Osmosis of Potato Cells in Various Salt Solutions

2516 Words6 Pages

Investigate the Osmosis of Potato Cells in Various Salt Solutions Introduction I have been asked to investigate the effect of changing the concentration of a solution on the movement of water into and out of potato cells. I will be able to change the input of my experiment. The input variable will be the concentration of the solution. The 100% solution is sodium chloride dissolved in water (salt water). This will be referred to as the 100% solution from now on. But the type of solution is not important as Osmosis is all about differences in concentrations. The output variable will be the weight of the potato chips, the movement of the water into and out of the potato. Osmosis is the diffusion of water through a semi-permeable membrane from high concentration of water to a low concentration of water. The water molecules move freely through the semi-permeable membrane this is a passive process. We will do this experiment by placing potato chips in different strength solutions and checking for mass increase/decrease. Prediction I hypothesize that if we place potato chips in different strength solutions that there should be different results, some with noticeable changes in mass the other will be nearly the same. The potatoes should gain/lose mass by the movement of water. If there is a change in mass it is because water has entered or left the cell. So the experiment will be based upon the movement of water. The first potato chip will be placed in a zero percent solution. I believe that this will increase the mass. I believe this because the zero percent solution has a lower concentration then the cell sap inside the potato. The potato takes on the water through Osmosis and the cell pushes out from inside the cell making it swell and become more rigid. The second potato chip will be placed in a fifty percent solution. I believe that the mass will not change for this potato chip because the concentration of the cell sap and the solution is nearly the same. This means the concentration will be nearly even inside and outside the cell. But this does not mean that osmosis is not taking place. Osmosis is the movement of water, the water still moves between the semi-permeable membranes. The third potato chip will be placed in a hundred percent solution. I believe that this will make the potato chip shrivel and become flexible and stringy. This is because t... ... middle of paper ... ...surface area will take on more water in a set time. For example if a potato chip is cut in a wavy shape or is crinkled it could have the same weight as any other potato chip but it would have a larger surface area. This could affect your results. So you must be careful in cutting the same shape potato chips. The slight difference in our experiment was negligible so we did not take it into account but it might have helped to make one of those anomalous results. All the anomalous results were negligible. They could be caused by anything. Form a slight increase in room temperature to the cell membrane being damaged when being cut. If I were to repeat this experiment I would try to make sure there are no anomalous results. The experiment would take a longer time and would be conducted in a sterile lab where there are no possible ways of the experiment being effected. In conclusion the experiment was a success we got the results we expected and they proved our hypothesis. But this experiment could always be repeated maybe on a much larger scale over and over again. This experiment suggests that there is a connection between the concentration of a solution and the movement of water.

Open Document