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

    However, results are not very precise (I'll talk about that later) and it is hard to say accurate concentrations.

  1. Experiment to find the water potential of the cytoplasm of potato cell (Solanum tuberosum ...

    From my results in table 1.4, they show the T and P value that I get after doing the paired T-test. All of my results are highly significant since all of the T value is larger than critical value (2.78).

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

    As a result, the cell will not gain or lose water. (1999, Brown)But if the medium is hypertonic, the cell will lose water through osmosis. This happens when the water concentration surrounding the cell is low. This effect causes the cell to lose all its water resulting in the whole organism's death.

  1. Testing the solute concentration of potato cells

    In other words, depending on the concentration inside and outside the semi-permeable membrane, water molecules move (Clegg, 2007). This also applies to the plasma membrane of potato cell. Through the plasma membrane controlling the entry and exit, water molecules whether inside or outside the cell would move to the side of higher solute concentration.

  2. Designing an Osmotic Potential Experiment with Potatoes

    This will be for both my independent variables. The dependent variable is what I will be measuring, I will be measuring the change in mass, and then convert them to the percentage change.

  1. An experiment to show the water potential of potato cells

    Molarity is the measure how concentrated something is. The reasoning why I think its starts to swell at first but then shrink is because the less concentrated a solution is causes it to have more water to be available in its surroundings. So the more concentrated the solution is will cause there to be less water in their

  2. Water potential of potato cells experiment.

    Results: Sucrose solution concentration (M) Length of potato chip (mm ± 0.5) Initial mass of potato chip (g ± 0.01) Final mass of potato chip after 30min submersion in sucrose solution (g ± 0.01) Change in mass of potato chip after 30min submersion in sucrose solution(g ± 0.02)

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