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Introduction

To find the water potential of the cytoplasm of potato cell (Solanum tuberosum linnaeus) Observation: 1. Potato (Solanum tuberosum linnaeus) 1 strips turn into dark colour when it gets oxidized because it exposed to air too long. 2. Potato (Solanum tuberosum linnaeus) strips become turgid after putting in the 0.1 mol sucrose concentration for 30 minutes. 3. Potato (Solanum tuberosum linnaeus) strips become flaccid after putting in the 0.5 sucrose concentration for 30 minutes. Raw data: 2.5cm potato (Solanum tuberosum linnaeus) strips, cock borer number 1 and number 2 Table 1.1 Mass of potato (Solanum tuberosum linnaeus) strips before putting into sucrose solution Concentration of sucrose solution/mol dm3 Trial Mass of potato (Solanum tuberosum linnaeus) strips before adding into sucrose solution/g (0.01g) Mass of potato (Solanum tuberosum linnaeus) strips after adding into sucrose solution/g (0.01g) 0.1 1 0.53 0.58 2 0.55 0.59 3 0.58 0.62 4 0.57 0.61 5 0.57 0.61 0.2 1 0.56 0.58 2 0.58 0.61 3 0.57 0.60 4 0.63 0.65 5 0.65 0.66 0.3 1 0.56 0.55 2 0.58 0.58 3 0.57 0.57 4 0.72 0.71 5 0.75 0.74 0.4 1 0.62 0.60 2 0.66 0.64 3 0.60 0.59 4 0.55 0.54 5 0.60 0.58 0.5 1 0.61 0.56 2 0.61 0.57 3 0.70 0.66 4 0.60 0.57 5 0.60 0.56 Processing data: Concentration of sucrose solution/mol dm3 Trial Change of mass of potato (Solanum tuberosum linnaeus) ...read more.

Middle

When there is no net movement between water molecules, the water potential of solvent and the water potential of the solute are equal. The range of literature value of water potential is from 0.24mol to 0.31mol, which estimate to be -680 to -860 kPa5 because 0.24mol has water potential -680kPa and 0.30 mol has water potential -860 kPa. From my results (refer to figure 1.1), I found that concentration of sucrose is in 0.309mol 0.3mol and water potential ) would be -860kPa3 is in Isotonic which is when water potential of potato (Solanum tuberosum linnaeus) strips and water potential of sucrose solution is equal. My results are in the range of the literature value, which means my results are quite accurate. From this experiment I found that potato (Solanum tuberosum linnaeus) strips decrease in mass as well as in turgidity from concentration of 0.1 to 0.5mol. Potato (Solanum tuberosum linnaeus) strips put in 0.1 are the hardest and most turgid among others. Potato (Solanum tuberosum linnaeus) strips put in 0.5mol are the softness and most flaccid among others. Therefore, masses of potato (Solanum tuberosum linnaeus) strips in 0.1 mol of sucrose concentration gained the most in mass since sucrose solution in 0.1M is less concentrated, therefore there is low sucrose concentration and ...read more.

Conclusion

I think we can only improve above error by doing the experiment for three times or more because we cannot find five potato (Solanum tuberosum Linnaeus) strips with the same water potential for each concentration. However, we can compare the results together or find the average then see which results give a more significant difference to get a more accurate answer. Since potato (Solanum tuberosum linnaeus) strips will get oxidized if it exposes to air too long, therefore we need to prevent water evaporated. To make a fair test, we should start the experiment as soon as we can once we have pushing out 5 pieces of potatoes (Solanum tuberosum linnaeus) strips, so it can avoid water evaporated from potato (Solanum tuberosum Linnaeus) strips, make a fair test and get a more accurate answer. Another possible error may occur when we took out the potato (Solanum tuberosum Linnaeus) strips from the sucrose solution and dry them on the tissue paper because every time we use different forces and sometimes water may lose if we press too hard. To improve it, I think we can repeat the experiment for three times or more then we can find the average and compare the results to get a more accurate answer. _____________________________________________________________________ 1http://www.shgresources.com/id/symbols/vegetable/ 2 http://www.graphpad.com/quickcalcs/ttest1.cfm 3 http://dl.clackamas.edu/ch105-04/calculat.htm 4 http://www.ruf.rice.edu/~bioslabs/tools/stats/ttable.html 5 http://biology.clemson.edu/bpc/bp/Lab/110/osmosis.htm ?? ?? ?? ?? Biology IA Vivian Kok 12C ...read more.

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