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


Extracts from this document...


TO FIND THE WATER POTENTIAL OF PLANT TISSUE CELLS. AIM: To find the water potential of plant tissue cells by using different sucrose concentrations. What is water potential? Water potential is the ability of water to enter or leave a cell that is measured in Kilopascals(Kpa).Water can enter or leave a cell by the process called 'Osmosis', this is the movement of water from a region of high water potential to that of low water potential through a partially permeable membrane e.g. plasma membrane. Pure water is said to have a water potential of zero and it follows that the addition of solutes to pure water lowers its water potential, therefore the more solute added to pure water, the more negative its water potential. STRUCTURE OF A PLANT CELL. PREDICTION. When a cell is put in a highly concentrated sucrose solution, the water will move by osmosis from the cell to the solution because the water potential in the cell is higher than it is in the solution. As a result the cell decreases in mass and size; this is known as 'plasmolysis'.On the other hand when put in a less concentrated sucrose solution, the cell will gain water from the solution because this time the water potential of the solution is higher than that of the ...read more.


3. Use distilled water, molar sucrose solution and a syringe to make 20cubic cm (you are advised to make more than 20cubic cm) of each dilution in a beaker. Record in a table how sucrose and water you've used in every solution. 4. Mix the solution fully by using a stirring rod or just by shaking. 5. Pour the solutions into the appropriate test tube, arrange the test tubes in a systematic order and put them on the rack. 6. Carefully use the scalpel to remove the outer skin of the potato as it acts as a barrier. 7. Use a cork borer to cut 6 pieces of potato and a ruler to measure about 3cm in length of each potato piece. 8. Gently blot any excess fluid from each the potato before weighing each potato individually, if weighed with excess water the mass of the potato will be affected. Record this as initial mass. 9. To obtain accurate and reliable results, immerse the 6 potatoes in their respective sucrose solutions for 24hours. 10. After 24hrs remove the potatoes from the test tubes, blot any excess fluid from the out side and reweigh them. Notice the changes and record the new mass as final mass. ...read more.


In the 0.75M sucrose concentration, the water potential is lower than in the tissue and as a result the tissue losses water to the solution leading to decrease of mass referred to as plasmolysis. EVALUATION Some results are not on the straight line and these are called anonymous results, they may come up as a result of inaccurate measurements of dilution due to inaccurate apparatus e.g. using a measuring cylinder instead of a syringe, insufficient blotting, the regions of the potato used and how long the potato tissue was left in the solution. To improve the results, the potato tissues should be carefully dried before and after immersing them in the solutions, this is to avoid affecting the mass .The mass could also be affected if the whole of the potato cell is not immersed in water as part of the cell will not be in the solution. The potato should be left in the solution for long enough to the whole osmosis process to take place. However the results do not support the prediction made earlier as to what would happen to the cell when put in an equally concentrated sucrose solution i.e. 0. 5M and this could possibly be because different specie of potato was used due to limited number of the original specie. This could be improved by preparing enough potatoes of the same test. ...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. Marked by a teacher

    An Experiment to Determine the Water Potential (Ψ) of a Plant Tissue, using Discs ...

    3 star(s)

    -0.03) to an area with a low water potential (?) (i.e. -30). ? Pure water 0.00 Soil & plant root -0.03 Xylem vessel -0.30 Humid Air -30.0 This table shows the typical water concentrations. Aim The aim was to place discs of beetroot in different concentrations of water and observe the change in their mass.

  2. Determination of the water potential of potato tissue by a gravimetric method.

    Tap water often contains ions and other molecules such as chlorine, fluoride, sulphur, minerals, salts, and heavy metals such as copper, lead and iron. However the majority of the contaminants in tap water are large, and often insoluble, molecules which have a lesser effect on w than small soluble molecules.

  1. What effect does the sucrose concentration have on osmosis?

    I think that the procedure that was used was efficient and dependable upon. I had written in the plan what I would try to achieve and the method which was going to be used and I stuck by it throughout the entire investigation.

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

    I predict that this solution will cause the potato to loose the most amount of mass or the most water loss. I predict this is because now with this high concentration, the concentration of solute molecules is now very high outside the cylinder.

  1. Free essay

    Investigation osmosis in potato cells

    order I had put them in the test tubes as to not confuse myself as to which chip came from which solution. * I dried each chip with the paper towel and then placed each one on the scales so that I could weigh them.

  2. Determine the Water Potential of Potato tissue.

    Pure water has a water potential of 0. As all solutions have less water molecules per volume than pure water they have a lower water potential therefore all solutions have negative water potentials. The movement of water molecules is not totally random it is fixed.

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

    Water potential is calculated using the formula "Q [= ]Q[s + ]Q[p]". When a cell's ?Q[s]? =[ ]?Q[p]?, the water potential is 0, and the cell is fully turgid. Plasmolysis begins at the point when Q[p] = 0, since there is no longer any turgor pressure against the cell wall.

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

    A cell in this condition is said to be plasmolysed, which is an irreversible damage. [image003.jpg] In my experiment, I will vary the solutions and their molarity, as well as using two different kinds of plant tissue samples; potato and cucumber cores.

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