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

The aim of this experiment is to work out if potatoes lose or gain mass in different sugar solutions due to osmosis and to solve where the water concentration outside the cell is equal to the concentration inside the cell;

Extracts from this document...


The Aim: The aim of this experiment is to work out if potatoes lose or gain mass in different sugar solutions due to osmosis and to solve where the water concentration outside the cell is equal to the concentration inside the cell; this is known as the isotonic point. In the investigation I would have to be as precise and accurate as I possibly can in order to have a reliable set of results for a good conclusion. Introduction: I am going to perform an investigation on osmosis in potato cells. Osmosis is the movement of water molecules through a semi permeable membrane, separating solutions of different concentrations. The water molecules pass from a region of high concentration to a region of low concentration. The molecules will continue to diffuse until the area in which the molecules are found reaches a state of equilibrium, meaning that the molecules are randomly distributed throughout an object, with no area having a higher or lower concentration than any other. Many cell membranes behave as semi permeable membranes, and osmosis is a vital mechanism in the transport of fluids in living organisms, for example, in the transport of water from the soil to the roots in plants. If a cell is in contact with a solution of lower water concentration than its own contents, then water leaves the cell by osmosis, through the cell membrane. ...read more.


Fig. 1 Volume of distilled water (cm3) Volume of 1Molar sugar solution (cm3) Concentration of sugar solution (M) 10 0 0.0 6 4 0.4 2 8 0.8 0 10 1.0 I chose these certain concentrations because I wanted there to be a distance between the concentrations in order to get a wider set of results and a smother curve on my graph. If I chose concentrations that were close together I would not be able to see much difference between the concentrations and it would affect the graph because it would not be clear to see changes between concentrations. So in other words doing so makes my results more reliable because of the wide range. Precautions: During this investigation the measurements for the solutions had to be precise as to not change the outcome of the experiment. I had to ensure that I took care cutting the potatoes because I could have easily cut myself by accident. I also had to ensure that every time I handled the potatoes my hands were clean and dry. This was to stop any kind of contamination and made sure that I did not pass on any extra water onto the potato which would alter the tables of results for all concentrations. How I kept it a fair test? : To create a fair test certain aspects of the experiment will have to be kept the same whilst one key variable is changed. ...read more.


So I believe that the reliability of my investigation is sufficient to back up my conclusion. I have several proposals for further experiments to provide additional evidence for my conclusion. I would like to undertake another experiment with sucrose concentrations at 0.05 intervals from 0 to 1. I would like to do this as I feel it would provide a better and more reliable set of results and a more justified conclusion. When there are more concentrations the shape of the curve shape can be seen more clearly, I suspect that at the lower concentrations of sucrose the graph falls more steeply, flattening off at higher concentrations. I would also like to conduct an investigation, in conjunction with this experiment, to calculate the concentration of sap within the vacuole. To do this, I would find between which parameters the curve crosses the x-axis of sucrose concentration and retest at every 1% between these two parameters until I have found the concentration which contains a core that neither gains nor loses mass. This osmotic concentration would be the equivalent of the sap in the vacuole (isotonic point). As an extension to this investigation, I would run two experiments in parallel. All cores would be from the same potato, but one would run for an hour, as this one did and for the other the cores would be left in the solutions for longer, perhaps 24 hours, to establish if one hour is the end point of the osmotic diffusion. ...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

    Osmosis in Potatoes Lab. At which concentration of sucrose in water (% mass ...

    5 star(s)

    1.79% o At 48 Hours: [(1.459g- 1.506)/ 1.506] x 100= -3.12% 10% Mass by Sucrose in Solution o At .5 Hours: [(1.566g- 1.538)/ 1.538] x 100= 1.82% o At 24 Hours: [(1.644g- 1.538)/ 1.538] x 100= 6.89% o At 48 Hours: [(1.602g- 1.538)/ 1.538] x 100= 4.16% 20% Mass by

  2. Experiment investigating concentration of sucrose solution and potatoes

    The graph shows that the percentage gain and loss in inversely proportional to the concentration. The gradient does change in my graph. It gets less steep as X axis gets bigger. This is because the potato chip is becoming as flaccid as it possibly can, and so the change in

  1. Find the concentration of Potato Cell Sap.

    concentration of the sucrose solution and the change in length of the potato. My Scientific Knowledge supports this conclusion by explaining; In osmosis, water molecules travel from where there is a high concentration where there is a low concentration of water molecules, i.e.

  2. Investigate Osmosis in potato cell using different concentrations of sugar solutions.

    After the first three strips have been in the first solution for 10 minutes I will place three more strips in the next solution. When I do this I will also restart the stopwatch. So that when the stopwatch reaches 10 minutes again I will no to take the strips

  1. Investigating the cellular water potential of potato cells.

    When there is a lower concentration of sucrose solution outside the potato cells, the water molecules will enter the potato cells by osmosis, and cause them to become turgid. This is more likely to happen when there is a low concentration sucrose solution outside the potato cells because the water potential will be higher outside the potato cells.

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

    been over or just under 30ml of solution in one of the boiling tubes, or an error was made during the weighing of the potato segments. Also the time I left the potato segments was not timed. If I had timed the experiment I could have been able to repeat

  1. Osmosis, What is the effect of sucrose concentration on the rate of osmosis in ...

    Small young potatoes are sweeter than larger, older ones. To solve this problem, I will just use a single large potato for all of my potato pieces to prevent shifts in the graph line from occurring as I change to a different potato. 6) Concentration of surrounding solution: The concentration of the solution is the variable that I am measuring.

  2. To find out the concentration of cell sap

    0.3 Average 0.35 Average Results Solution Molarity Weight gain or loss 1 -0.55 0.8 -0.65 0.6 -0.45 0.4 -0.30 0.2 0.10 0 0.35 Analysis According to the results the cell sap in the potato have a molarity just over 0.2.

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