• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

QN: HOW DO YOU CALCULATE THE WATER POTENTIAL OF CELLS IN A POTATO?

Extracts from this document...

Introduction

SORAIYA MANJI I.B. 1 BIOLOGY QN: HOW DO YOU CALCULATE THE WATER POTENTIAL OF CELLS IN A POTATO? Aim My aim was to estimate the water potential of potato tuber cells using sucrose solutions of different solutions. Hypothesis I assumed that the mass of the potato cylinder in distilled water will remain the same after leaving it in the water for about two hours because of no difference in the concentration. I also assumed that as the concentrations of the solutions increase, the mass of the potato cylinder after leaving it in the solution for two hours will decrease, and the change in mass will be higher with greater concentration. This is because more water will come out of a cell with less concentration of solution inside than outside. Variables The independent variable is the concentration of all the sucrose solutions, i.e. 0.2, 0.4, 0.6, 0.8 and 1.0 mol/dm3. ...read more.

Middle

5) This was repeated for the remaining of the potato cylinders and the masses were also noted on the filter papers. The label of the tube in which each cylinder was going to be put was also written on the filter paper. 6) The cylinders were then lifted with forceps, put in their respective test tubes and stoppers were attached. 7) The test tubes were allowed to stay for about two hours. 8) After this, the cylinders were removed with forceps and the water was wiped off gently, using a filter paper. 9) Each cylinder was placed on the balance and their masses were noted again. Data collection The following table shows the masses of the filter paper and the filter paper with the cylinder, to be used in the different test tubes. Table 1: Test tube Mass of filter paper/g Mass of filter paper + cylinder before expt./g D.W 0.91 2.11 0.2 0.85 2.05 0.4 0.95 2.13 0.6 0.83 2.02 0.8 0.84 2.02 1.0 0.84 2.01 The following table shows the mass of the cylinder after the cylinders were left in their solutions for two hours. ...read more.

Conclusion

The percentage change in mass can be calculated in the following way: Change in mass of cylinder before and after expt. � 100 Original mass of cylinder This is shown in the table overleaf: Table 4: Test tube Change in mass/ g Percentage change in mass D.W 0.25 17.3 0.2 1.03 14.2 0.4 0.82 30.5 0.6 0.83 30.3 0.8 0.77 34.7 1.0 0.88 24.8 Conclusion and evaluation From the results, it could be seen that there was some error in the experiment, because the percentage change in mass did not increase in all cases as the concentration increased. This is possibly because the cylinders were cut from different potatoes, which caused a variation in the result. Another reason for the error could be that the concentrations of the sucrose solutions were not accurate. Another method of carrying out an experiment of osmosis is to use a red blood cell instead of a potato. The red blood cell would probably increase in size when put into water. Another investigation that can be carried out is how time of keeping the potato cylinder in the solution can affect its water potential. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. The effect of concentration of sucrose solution on the osmosis in potato

    In addition, the remaining liquid from previous solution may also affect the concentration of 15 % sucrose solution. If the concentration of sucrose solution is higher than expected, then the mass will decrease more.

  2. Testing the solute concentration of potato cells

    after 25 minute-reaction with the initial length of 3.5 cm Note: Li = initial length of potato = 3.5 cm Lf= final length of potato Note: uncertainties are

  1. Osmosis. By this investigation, I tried to find out the changes in potato ...

    * We didn't stir any of the solutions. * Potato cylinders weren't completely dry while measuring its' masses. Conclusions and evaluations By this investigation, I tried to find out the changes in potato cylinders' masses dependently on sucrose solution outside and hence - concentration of sucrose inside the potato, which has the same water potential as solution outside the cylinder.

  2. Biology independent investigation, Ecology

    has no comparison so its change in mass cannot be found, and this applies for the dry root weight as well. The experiment was also allowed 14 days of growth instead of 10 days. To measure the fresh change in mass the mass was of the seed was taken (remove excess water and perlite)

  1. LAB-What infuences blood pressure

    19,45 63 166 72 116 74 141 73 58,5 1,73 19,55 65 110 70 110 70 110 70 48,2 1,57 19,55 67 108 71 116 72 112 71,5 50,8 1,61 19,60 66 + 110 70 110 70 110 70 47,2 1,55 19,65 65 110 70 110 70 110 70 58,8

  2. Osmosis. Aim: To study the effect of distilled water and different concentrations of sucrose ...

    0.0 (Distilled water) 43 42 41 43 42 42 41 40 41 42 42 43 0.2 40 40 40 41 41 41 40 42 41 41 40 42 0.4 38 39 40 39 40 39 39 40 39 39 38 39 0.6 37 37 37 39 39 38 39 38

  1. Osmosis Experiment. This experiment is to consider how salinity influences osmosis in potato cells.

    If the medium is hypotonic, the cell will gain water through osmosis. This occurs when the solution surrounding the cell has a high water concentration. (2010, Wikipedia) The second scenario is if the medium is isotonic. This is when the solution has the same water concentration as the cell.

  2. Investigation of osmosis in potato strips by measuring the length of the strips after ...

    through a partially permeable membrane . In this case, the cells making up the potato strips have lower concentration of solutes (hypotonic solution) in comparison to the different concentrations of sucrose solutions that surrounds the cell . The water molecules will move out of the cells to beakers containing different

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work