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

Investigation into the water potential of celeriac.

Extracts from this document...


Investigation into the water potential of celeriac PLAN AIM: This is to investigate the water potential of celeriac when placed in different concentrations of sucrose solution. To do this I will be studying the process of osmosis to explain my prediction. Celeriac, being a root vegetable means it has a cell like any plant with a permeable cell wall and a selectively permeable cell membrane. The cell membrane only allows for water molecules to pass through which is why osmosis, the movement of water from a high water potential to a low water potential can be used. There is NO movement of sucrose molecules. HYPOTHESIS: I predict that as the sucrose concentration decreases in the solution the celeriac would increase in mass. The celeriac placed in pure water (weak solution) would cause the greatest change in mass as the water potential is the highest it can be (0). This is because the inside of the celeriac cells would have a concentration of substances (starch, sugars, other substances,) while the pure water has none. As a result, water molecules would diffuse in to the cells to increase the water potential of the celeriac. As the sucrose concentration increases in the solution, the celeriac's 'increase in mass' should start to decrease to. ...read more.


* The celeriac being quite a large vegetable can be hard to handle so when using the cork borer I should hold this securely. FAIR TEST - VARIABLES * Volume of sucrose solution should be constant in both tests. This allows for both tests to be valid. * The length & diameter of celeriac cylinders must be kept constant. To ensure this the same cork borer should be used. The lengths should not range more than 0.1 of a cm from 2. The increased length means there is more surface area. One of the factors that diffusion depends on is the surface area and if this is increased this can increase the rate of diffusion. * All test tubes should be left in the solution for the same time. This needs to be controlled as near as possible by placing the all celeriac as soon as the first one has been placed. They should be removed in the same order. * It is highly likely to be quite a range of mass of the cylinders. This is why it is essential that the 'mass of change' is to be recorded to get a valuable result. However I must take care to record the correct weight after with the corresponding weight before. ...read more.


4. When making up the solutions there were times I had to use more than 30ml of sucrose or water. Therefore when drew up 30ml and then an extra 10ml it could have been possible some residue of water or sucrose could have been left. The solutions were then not made as accurately as intended. To improve this experiment I will certainly need to take more readings for each concentration. For example the average percentage chamnge in mass was greater for 0.4 M than it was for 0.5 M, which does not tie in. I should decide to blot each cylinder for exact equal times as I suspect this greatly disrupted the results. I have obtained outside data to form a graph of the water potential of various sucrose solutions. When I look at my graph I see that at 0.33M there was no change in mass as the point crosses the x-axis. On the line of best fit this shows as 0.35M. The potential must be somewhere between 0.3M and 0.4M. I can therefore suggest that as there is a range, the celeriac's water potential must be between -850kPa to -1075kPa. My experiment was not accurate enough to show an exact number which is why a range has been provided. By increasing the number of results would increase the accuracy of the 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 GCSE Green Plants as Organisms 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 GCSE Green Plants as Organisms essays

  1. Determine the water potential of potato tuber cell with the varying affect of solute ...

    You need to remember to place the bungs (1) on firmly or some of the water from the solutions will evaporate away changing there concentration due to the heat. (2) Use your cork borer (4) and bore out 6 potato cylinders and with the blade (5)

  2. An Investigation into Water Loss from Plants.

    The diameter was measured using a graticule and the cross-sectional area obtained using the formula: The area was calculated to obtain a constant area that the stomata were counted in as all leaves were different sizes so would have had different total amounts of stomata.

  1. Investigate and find the water potential of baking potatoes and sweet potatoes in (N/mm2) ...

    could submerge the test tube containing solutions into a water bath at a reasonable temperature like 30�C. This would be a better temperature, as it would be more stable than fluctuations in the room temperature. Also, they protein water channels would benefit more and function more efficiently at a temperature greater than 25�C.

  2. The factors affecting the rate of permeability in a cell membrane?

    * I then washed the beetroot with distilled water because it is clearer then tap water as it can maybe affect the experiment. This is done to get rid of excess red pigment and leakage. * I will place the test tube in a water bath this will be done

  1. Construct a rocket from a discarded PET (Polthylene Teraphetlate) drink bottle.

    Mass of the system (g) Weight of the system (N) Time (s) Maximum Horizontal displacement (m) 1 46 400 4000 2.11 23 2 46 400 4000 2.14 20.4 3 44 400 4000 2.99 21.5 Average 45.67 400 4000 2.87 21.6 600ml: Trial no: Air pressure in the bottle(kPa)

  2. An Investigation into Species Diversity with distance along a Pingo.

    T-test 6.35 2.050 Null hypothesis rejected, there was a significant difference in the light intensity between the top and the bottom of the pingo soil water content chi-squared test 36.556 16.900 Null hypothesis rejected, there was a significant difference in the distribution of water along the pingo Buttercup distribution chi-squared

  1. The investigation is aiming to look at transpiration.

    Xylem fibres resemble the scelerenchym fibres due to the fact that they have overlapping walls they have narrow lumens than xylem hence they are stronger and offer mechanical strength to the plant. PHLOEM They are composed of living cells within the cytoplasm and have no mechanical function.

  2. Osmosis investigation. My prediction is that as the concentration of the solute increases, ...

    1 stop watch- They are precise at keeping a timer and have a reasonable alert feature, no need for an alternative. 1. Weighing scales- there aren't many alternatives, perhaps displacement, but the trade off for scales is silly. It would be sensible to use better higher grade scales as

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