Incipient Point of Plasmolysis Lab

Investigation of the bakshis of incipient plasmolysis of onion cells (Allium cepa) using NaCl (Sodium Chloride) tightfistednesss of 0. 1M, 0. 2M, 0. 3M, 0. 4M, 0. 5M, 0. 6M Design Research Question (Aim) The aim of this lab was to break the point of incipient plasmolysis of onion (Allium cepa) cells using Sodium Chloride (NaCl) minginesss of 0. 1M, 0. 2M, 0. 3M, 0. 4M, 0. 5M, 0. 6M. Hypothesis When the water concentration of a solution let onside the cell is lower than the concentration inside the cell, water will move from the inside to the turn outside of the cell due to osmosis.As we increase the concentration of the NaCl solutions we open used (0. 1M to 0. 6M), much than moles of NaCl are fade out in the solution. Thus, the solutions increases in solute concentration but decreases in water concentration. We can therefore assume the high the concentration of the NaCl solution, the higher the number of plasmolysed cells as water moves outside the cell in exhibition to dilute the NaCl concentration. Data Collection and Processing Table 1 The number of plasmolysed onion cells (out of 30) 1 for each of the 6 NaCl concentrations (0. 1M, 0. 2M, 0. 3M, 0. 4M, 0. 5M, 0. M) for three trials Concentration (in M) Trial 1 (Number of Plasmolysed Trial 2 (Number of Plasmolysed Trial 3 (Number of Plasmolysed Cells 1) Cells 1) Cells 1) 0. 1 0 out of 30 0 out of 30 0 out of 30 0. 2 2 out of 30 0 out of 30 0 out of 30 0. 6 out of 30 4 out of 30 3 out of 30 0. 4 6 out of 30 12 out of 30 13 out of 30 0. 5 6 out of 30 16 out of 30 19 out of 30 0. 6 6 out of 30 30 out of 30 30 out of 30 Qualitative DataIn general, it was hard to keep an overview of the cells ane has counted yet and star has not as superstar only counted the cells at random. To this, it was hard to determine visu exclusivelyy whether a cell was plasmolysed or not so that one could bring assumed some cells to be plasmolysed although they were not. Finally, as the results of our first tr ial show, we did not allow enough time for the cells to plasmolyse so that the results became inaccurate. Table 2 The percentage of plasmolysed onion cells 3. 33% for all of the six solute concentration (0. 1M, 0. 2M, 0. 3M, 0. 4M, 0. 5M, 0. M) for three trials, including the average percentage of plasmolysed cells for the second and third trial only*, as well as for all three trials together Concentration (in M) Trial 1 (Percentage of Trial 2 (Percentage of Trial 3 (Percentage of Average Percentage of Average Percentage of Plasmolysed Cells Plasmolysed Cells Plasmolysed Cells Plasmolysed Cells for Plasmolysed Cells for 3. 33%) 3. 33%) 3. 33%) second and third trial all three trials 3. 3% 3. 33% 0. 1 0. 00% 0. 00% 0. 00% 0. 00% 0. 00% 0. 2 6. 67% 0. 00% 0. 00% 2. 22% 0. 00% 0. 3 20. 00% 13. 33% 10. 00% 14. 44% 11. 67% 0. 4 20. 00% 40. 00% 43. 3% 34. 44% 41. 67% 0. 5 20. 00% 53. 33% 63. 33% 45. 56% 58. 33% 0. 6 20. 00% 100. 00% 100. 00% 73. 33% 100. 00% * = I eat ci pher the average for the second and third trial only in furnishition to the overall average so that I can draw another graphical record of the averages of the second and third trial only since the results of our first trial seemed to be inaccurate. Sample CalculationsPercentage In format to determine the percentage of plasmolysed cells for each solute concentration, one can use the following formula (NT) x 100, where N stands for the numerical value (in this gaffe the number of plasmolysed cells we score counted) and T stands for the total (in this case 30). For example, if one would want to calculate the percentage of 2 out of 30, this would result in the following formula (230) x 100, since 2 is the numerical value (the number of plasmolysed cells we have counted) and 30 is the total. Average To calculate the average, one simply adds the values and so divides it by the number of values.One could also use the formula (? x) n, where x are the various(prenominal) values of pla smolysed cells for each trial and n is the number of values. For example, if one would want to determine the average for the number of plasmolysed cells for the concentration of 0. 6 M, one would simply add 20, 100 and 100 and then divide it by 3, since the number of plasmolysed cells is the x-values and 3 in this case is the n value. Figure 1 The average percentage of plasmolysed cells 3. 33% of all three trials determined for each of the six NaCl concentration. The graph shows a linear trend-line in order to determine the point of incipient plasmolysis. pic Figure 2 The average percentage of plasmolysed cells 3. 33% of only the second and third trial determined for each of the six NaCl concentration. The graph shows a linear trend-line in order to determine the point of incipient plasmolysis. pic Conclusion & Evaluation Conclusion As the NaCl concentration outside is increased, more NaCl molecules are dissolved in the solution causation the solution to have a higher solute concen tration but a lower water concentration. The water from the plant cell thus has a higher concentration than the outside diffuses (through osmosis) in order to dilute the NaCl concentration.The turgor pressure that maintains the shape of the cell by pushing the plasma membrane against the cell wall is then lowered causing the cells to shrink. This is known as plasmolysis. Our hypothesis the higher the concentration of the NaCl solution, the higher the number of plasmolysed cells as water moves outside the cell in order to dilute the NaCl concentration was therefore correct. Furthermore, we have used Figure 2 in order to determine the point of incipient plasmolysis as the results are more representable of the whole since the first trial was not included.Figure 2 indicates that the point of incipient plasmolysis lies at approx. 0. 42M. Supporting my findings, a similar experiment was done only with saccharose solution instead of NaCl. The results show that the point of incipient plasm olysis lies of this experiment lies approx. 0. 38M which is fairly close to my results (Stadelmann, 156). In general, one can assume that the higher the concentration of the outside solution, the higher the number of plasmolysed cells as water moves outside the cell in order to dilute the outside oncentration. Evaluation Limitation Significance procession It was hard to determine the number of As there were generally more than 30 cells We could have used the method of a plasmolysed cells visually as we merely counted visible in the eye piece, it was not too hard hemocytometer instead so that we could have 30 visible cells at random and did not have an to count 30 individual cells.However, we couldcounted the number of plasmolysed cells per overview of the cells we have already counted. have still counted one cell twice and assumed square. In addition, it was hard to determine if a cellthat it was two different cells. This was plasmolysed or not. limitation therefore causes an overall inaccuracy. Furthermore, we could have assumed some cells to be plasmolysed although they were not plasmolysed. We only estimated what the point of incipient This only has a slight significance on the We should have done the lab with the NaCl plasmolysis approximately would approximately exact accuracy of the point of incipient concentrations we were given and then determine be basing it on our graph (figure 1) and only plasmolysis. where the point of incipient plasmolysis using concentrations of 0. 1M, 0. 2M, 0. 3M, 0. 4M, approximately lies.Then, we could have done 0. 5M, 0. 6M. the experiment with more accurate solutions such as 0. 45, 0. 475 in order to find the exact point of incipient plasmolysis. For our first trial we did not allow enough out-of-pocket to this limitation, our overall average wasWe should have allowed more time for the cells time for the cells to plasmolyse. lowered leading to a higher point of incipient of the first trial to plasmolyse. We could have plasmolysis. In general, those results were also simply repeated this trial. outliers which affected the accuracy of our affect data. We have only done three trials of the This is very significant in our case as the Instead, we should have firstly determined experiment. results of the first trial therefore had a where the point of incipient plasmolysis great effect on the accuracy of our processed approximately lies and then repeated the data. experiment with these NaCl concentrations at least 5 times. We did not agree on an overall method of the The more NaCl was used, the more cells were harmonise on an overall amount of drops of NaCl amount of drops of NaCl we used. likely to plasmolyze as more water would such as 1 drop or agree on an amount such as diffuse outside the cell in order to dilute the1mL and then use a pipette and a calibrated solution. cylinder in order to measure that amount. Works Cited Stadelmann, E. J. Methods in Cell Physiology. Ed. David M. Prescott. New York Academic, 1966. Print.