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Find out the concentration of sucrose solution that is equivalent to the osmotic potential of Potato tuber cells.

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Introduction

Osmosis Investigation By Christopher Stylianou Aim The aim is to find out the concentration of sucrose solution that is equivalent to the osmotic potential of Potato tuber cells. Factors All the independent variables, which could affect the investigation of Osmosis, are: > Mass- By changing the size of the cell could change the amount Osmosis occurring. > Concentration of Solution- By changing the concentration of the solution surrounding the cell could change the amount of Osmosis occurring. > Temperature- By changing the temperature of the solution or cell could change the amount of Osmosis occurring. > Size- By changing the surface area of the cell could change the amount of Osmosis occurring. Investigation I have decided with the research I have below to investigate the Concentration of the Sucrose Solution independent variable. This is because I can use a scale of 10 different solutions. E.g.: - 1 Molar of Sucrose Solution to Water or 0 Molar of Sucrose Solution to Water. Then I can work out how much each cell has gained or lost by weighing them and then see which is the nearest Potato tuber cell not to change it's concentration from the beginning will be the right concentration of sucrose solution to equal the concentration inside the Potato tuber cell. ...read more.

Middle

Water (cm�) 1 Molar 30 0 0.9 Molar 27 3 0.8 Molar 24 6 0.7 Molar 21 9 0.6 Molar 18 12 0.5 Molar 15 15 0.4 Molar 12 18 0.3 Molar 9 21 0.2 Molar 6 24 0.1 Molar 3 27 0 Molar 0 30 Mix the solutions using a glass rod. Then take 11 of the potato tuber cells (potato cubes) and place 1 into each beaker. Then set the timer on and leave for 24 hours. Repeat this again to get two sets of results. After 24 hours, take each potato tuber cells out of their beakers and wipe off any excess solution. Then weigh each cell again and record this into your results. Then work out how much weight the cell has gained or lost in each solution by subtracting the starting weight by the finishing weight. Fair Test: - To make it a fair test you must carry out these precautions: - * The measuring and the Sucrose and Water are accurate by using a measuring cylinder. * Don't use the same measuring cylinder for the Sucrose and the Water because it might contaminate the solutions and make it an un-accurate and un-fair test. * Make sure that each potato tuber cell is 1cm� and doesn't have excess liquids on them. ...read more.

Conclusion

Also, the temperature, mass or/and surface area of the potato tuber cell could have changed which would affect the results. I think my method is good because you can get accurate results by using simple apparatus and knowledge. But it could improve my method by controlling the other factors better by making sure that the potato didn't have any kind of excess liquids on it, the mass was the same weight every time and the surface area was the same size every time. I could only do this with special equipment that wasn't provided for this experiment. Also, if we put the experiment in a controlled temperature environment, this wouldn't affect the results either. I had preliminary work to help me with the investigation, which was very useful in making my prediction. But now I have done the experiment, I could concentrate around the 0.3 - 0.4 Molar Sucrose Solution and go up in hundredths instead of tenths to get a more precise result. I could do another experiment which the same method but instead of using sucrose, I could use a different mineral to see if it will affect the results in anyway. E.g.: - Starch. I got my research from the Biology GCSE textbook and from the Internet- http://www.purchon.com/biology/osmosis.htm ...read more.

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