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

To determine the isotonic point of plant tissue (potato).

Extracts from this document...


AS COURSEWORK To determine the isotonic point of plant tissue (potato). Introduction. This experiment is to determine the role of water potential of tissues in plants most particularly the movement of water into and out of potato storage tissue so that the isotonic point can be identified. Prediction. Potato is a plant that contains more starch grains and immature chloroplasts in the plant cells. Thus it has a lot of starch and little or no mono or disaccharides. I would predict that the when the potato chip is left in the solution it will increase in mass or decrease if the concentration of the solution is high or low. This is so because as the solute concentration increases this creates a hypertonic solution, thus more cell sap will be lost to create an osmotic balance. Also as the solute concentration decreases it creates a hypotonic solution and so less cell sap is lost but more solution is gained into the cell sap from the surrounding solution to create and maintain an osmotic balance. At a certain concentration of solute, there will be no change in mass of the potato. ...read more.


5. Temperature. The experiment will be carried out in the lab and might possibly last overnight. Because I want to keep the temperature constant a water bath will be used to ensure this. This is important because high temperature can cause molecules to have more kinetic energy and move faster thus causing osmosis to occur faster so this will cause different readings. Agovi. Measurements. I will be measuring the sugar concentrations. The concentrations will be in five (5) different concentrations (i.e.) 0, 0.2, 0.8, 1 & 5M. The readings will be replicated three (3) times with a range of at least five (5) times. This is so because it will enable me get accurate measurements. Possible methods. I can identify the isotonic point by measuring the weight, length or volume of the chips. I will measure the change in mass as its quite accurate since change in length or volume is not because the cell wall is rigid being made out of cellulose and thus will allow the cell to expand or contract to a limited extent. ...read more.


9. Calculate the change in mass per gram for each concentration and then the average change in mass per gram in order to allow accurate comparisons. You can then plot a graph of the average change in mass per gram against the sucrose concentration. Equipment. 15 watch glasses 18 cylinders of potato Agovi. Meter rule Top pan balance 50ml syringe 5 Distilled water 350cm Sucrose solution 750cm, 1M Test tubes 20 Blotting paper Scalpel Risk assessment. 1. The scalpel is so sharp so care should be taken whilst cutting the cylinders. A tile should be used and cutting must be done away from the body. 2. Pushing the potato away onto the tile, use Cork borer and the cylinder can be pushed out using a blunt object e.g. pencils. 3. All glassware should be handled carefully to ensure no breakages. Should any breakage occur, it should be cleaned and cleared away to avoid any risk of injury? 4. If any sucrose solution is spilt it should be cleaned away otherwise the area will be sticky. 5. 6. 7. 8. ?? ?? ?? ?? 1 ...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 Life Processes & Cells 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 Life Processes & Cells essays

  1. Marked by a teacher

    An Experiment to determine Water Potential in Potato Tissue.

    4 star(s)

    To improve this problem, make sure that you dry the plate before you place your potato and also let the weight measurer settle completely before using it. I think that when I was cutting up the pieces of potatoes, the accuracy of measuring length was very poor.

  2. 'Investigating how isotonic, hypertonic and hypotonic solutions affects the total mass of a potato ...

    1.98 2.08 +0.1 5 B 0.5m 20ml water 20ml salt sol. 1.98 1.81 -0.17 -8 C 1m 0ml water 40ml salt sol. 1.98 1.71 -0.27 -13 Graphs: Conclusion & Evaluation (based on preliminary): Although my preliminary did not run as I had hoped, it gave me the opportunity to repair

  1. To determine the water potential of potato tuber tissue

    I expect the line to cross the x-axis when the sucrose solution is at around 0.30M to 0.35M (this is between -800KPa and -900KPa, see table below). I get the estimated value for the water potential of the tissue by looking at my pilot study graph and results.

  2. Osmosis: Isotonic Point of Potato

    Do this 18 times. * Then cut the potatoes into smaller pieces making sure they are approximately the same size. * Measure the pieces to make sure that they are all exactly same size. * Measure the mass of each piece of potato making sure they are the same mass.

  1. An Investigation to Determine the Water Potential of a Plant Tissue.

    The cells will become flaccid and therefore the potato tubes will reduce in length. At low concentrated solutions (eg 0.1M) water will move into the cells because the water potential will be higher in the solution than in the cytoplasm.

  2. To determine the concentration of the cell sap in potato storage tissue. By using ...

    Like it wants to 'balance out' the water concentration on either side of the cell walls. This is what Osmosis aims to do, allow water to flow in and out in order to achieve an equal concentration of water on either side of the semi permeable membrane.

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