• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12

To investigate the effects of using different concentration of Sucrose solutions in Osmosis with a cucumber

Extracts from this document...


*Planning* Introduction Throughout this experiment I shall be investigating how different solution concentrations can affect osmosis. For this I have chosen to use sucrose solution, and cucumbers. Diffusion is the movement of a substance through a fluid (i.e. liquid or gas). In a solution, diffusion happens when there is a higher concentration of a substance in one part of the solution than in another. It spreads until the concentration is the same throughout the solution. Osmosis is the diffusion of water from an area of low concentration (i.e. high concentration of water) to an area of high concentration through a selectively permeable membrane. In both plant and animal cells water can pass through but in the latter there is no cell wall to keep the cell from bursting. So if the water concentration is higher outside the cell, then water will pass until the cell bursts. (Unless a stable point is reached before). However in plant cells, the cell wall, which is entirely permeable and very strong, can keep the cell from bursting. Turgor and plasmolysis. These are the two different "states" in which a cell can be left if it's concentration within is not the same as outside. (Note, animal cells can go flaccid but not turgid, they burst instead). ...read more.


Mass after (g) % Change in mass 0M 3.20 3.50 9.38 0.25M 3.60 3.50 -3.77 0.5M 3.80 3.80 0.00 0.75M 3.80 3.70 -2.63 1.0M 3.40 3.20 -5.88 Averages Concentration Mass before (g) Mass after (g) % Change in mass 0M 3.35 3.65 8.96 0.25M 3.60 3.60 0.00 0.5M 3.40 3.35 -1.47 0.75M 3.50 3.40 -2.94 1.0M 3.45 3.30 -4.35 See also the graph plotted by hand on the next page. *Analysing evidence* Reminder of hypothesis: * When the slice of cucumber is placed in D.W. it will gain mass because the concentration of water will be weaker inside it's cells than outside. (This was true) * When the solution is very weak (i.e. not much Sucrose) then the cucumber might still gain mass depending on how high the concentration is inside the cucumber. (This was also true) * As the concentration increases, the loss of water from the cells will increase. This will be shown by a change in mass. (This was also true) It has been found that there is a relationship between the concentration of a solution and the change in mass of a plant cell. It has been found that a weak solution (i.e. ...read more.


The best solution (which is what I did) is to give the cucumber slice a quick shake and dab it on filter paper. The experiment could be improved by trying a wider range of solutions (not just sucrose) and at different concentrations. The tests should be repeated as many times as possible and a longer time should be used to let the slice absorb or eject water. This should be done because it would eliminate any extreme end results and give better averages. I think that my results were accurate enough to reach a firm conclusion which is probably correct as it would agree quite strongly with my background information. Further work could include researching what chemicals are in solution inside the cell and whether using different solutions would effect osmosis. Also the cucumber slices could be tested at different stages of development to test for a specific time period during which the starch in the sap cells is developing. Also another test could be to do exactly this same experiment after having left the slices of cucumber for different periods of time in sunlight and or shade to see how the concentrations inside the inner sap vacuole would change as the cells were dying. The tests would be almost identical to this one with perhaps a few changes in their preparation. ...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. What effect does the sucrose concentration have on osmosis?

    Hypertonic - In biology, a hypertonic cell environment has a higher concentration of solutes outside of the cell. Hence, in a hypertonic environment, osmosis causes water to flow out of the cell. If enough water is removed in this way, the cytoplasm will have such a small concentration of water that the cell has difficulty functioning.

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

    (Extra points on fair testing) We must make sure that this test is fair because if it is not a fair test we will be obtaining the wrong results. First of all, and most importantly, we will have to get the measurements and the weights of the solutions and the potatoes as exact, and as accurate as possible.

  1. The effects of organic effluent from the seweage on the biodiversty in a freshwater ...

    * Put the species back into the water where you collected them from, as the conditions of those sites are necessary for their survival. * Don't pollute the stream by throwing away rubbish as this may influence further water pollution.

  2. The aim of this experiment is to determine the water potential of celeriac cells ...

    7 7 7 7 7 Length after (cm) 7.5 7.2 7.2 6.9 6.8 Percentage change (1dp) + 7.1 + 2.9 + 2.9 -1.4 -2.9 Analysis of Pilot A regression line drawn on the graph of the pilot results (see below) shows that there is no change in length when the tubes are in a solution of about 0.7 mol dm^-3.

  1. What effect different solutions, with the same water potential, have on potato and cucumber ...

    Whether the water enters by Osmosis will depend on the balance between external and internal solute and water potentials. If the solutions on each side of the partially permeable membrane have the same water potential, then there will be no net movement of water molecules across the membrane.

  2. Water moves from a high concentration gradient of water to a low concentration of ...

    Each potato has the same amount of mass and they will be put into different concentrations of water. 2. Temperature- As we increase the heat of the solution the experiment we speed up. But this will have no effect on the potato since it is the movement of the water the not the speed of the experiment.

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

    such as when a cell is turgid. Water potential is calculated using the formula: Water Potential = Solute Potential - Pressure Potential ? = ?s - ?p Solute potential is negative, since the solute dissolved lowers the potential below zero, as already explained.

  2. Investigate the cell sap concentration of solute in a potato chip using osmosis and ...

    water potential than the outside of the cell for example, the soil. Then the water will diffuse out of the cell by osmosis into the surrounding soil because it is moving from a high potential to a low potential, as the vacuole shrinks the cell becomes flaccid.

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