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

An Investigation into Potato Tissue

Extracts from this document...

Introduction

An Investigation into Potato Tissue Aim: To investigate how varying the sucrose concentration around piece of potato tissue affects the diffusion of water (osmosis) into or out of the cell. Introduction: Definition of Osmosis: This is the diffusion of water molecules from an area of high water concentration (dilute solution) to an area of low water concentration (concentrated solution) through a permeable membrane. The rate, again, depends on the surface area, the concentration gradient and the properties of the partially permeable membrane. A diagram of Osmosis: We have looked into osmosis previously in the experiment of turgid and plasmolysed onion cells, and a visking tube. Demonstration of Osmosis Using a Visking Experiment The Visking tube experiment was used to demonstrate osmosis. The Visking tubing was semi-permeable, which allows small molecules (water) to pass through, but it doesn't allow the larger ones (sugar). Apparatus * a small length of capillary tubing * a larger amount of Visking tubing * 0.5 sucrose solution * pipette Osmosis Experiments Factors that will affect the rate of osmosis will be the Independent variables, the dependent variables and the external variables. Independent variable = Concentration of sucrose solution - If the sucrose solution is changed, osmosis will change in rate and direction. Dependent variables = Change in mass of potato. ...read more.

Middle

Making it plasmoylised and decrease In both weight and length. Evaluation From this experiment I understood osmosis, a lot better. I thought though for my final experiment that I should make some changes to the variables to make it a fairer test. For example in this experiment I left them for 30minutes. I got pretty good results but I think that I possibly could get better. So in my final experiment think that I might leave them for longer maybe around an hour to give osmosis more of a chance to happen. I think that this experiment was accurate but for my final experiment I would like to improve it. I am quite confident with my conclusion as I think that it makes sense. If I was to look further into osmosis I think that I might do the same experiment a lot more, and in different paces as well, to see if the temperature varies. Weather osmosis works better in hot conditions rather then cold ones. In my next experiment again to keep it precise I think I might use an electronic balance that measures to 0.01(g). Making sure that the electronic balance is put back to zero each time. I also think that to be sure that my final experiment, my results are reliable Ill do it twice with two of each sucrose solution. ...read more.

Conclusion

If I had to do this experiment in more detail, again I think that I would do the same concentration of sucrose solutions as I think that they are a good range. I think that if I could change the experiment, I would do lots of the same solution, putting each of them in different spaces. For example, one outside, one inside, too see if osmosis worked well in hotter or colder temperatures. I did check the temperature in my experiment but the temperatures were extremely constant. This was good for my experiment as I wanted a fair test. Extremely different temperatures in my experiment would have maybe made the osmosis in one test tube work better then in another. I would have also left some for longer and some for shorter periods of time, as in my two experiments I found that half an hour wasn't long enough for osmosis to properly and I don't know what the right time period in a further investigation I would try and find this out. The last thing that I think that I would of done if given a longer amount of time and more resources would have been maybe to add a colour die to the water and sucrose solution to see if a could actually watch osmosis happen. ?? ?? ?? ?? Kelly Biology coursework ...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

    Investigating the effect of Sucrose Concentration on the Rate of Osmosis in Potato Chips.

    5 star(s)

    and 0.2mol/litre because the potato chips gained mass causing the cells to become stiff due to their filling of water. The water molecules in the solution where the sucrose concentration was 0.2mol/litre diffused through the partially permeable membrane from the outside of the potato chip cells where the water concentration

  2. Marked by a teacher

    How does the concentration of a sucrose solution affect the rate of Osmosis in ...

    5 star(s)

    at the end, but is still in a curve rather than a horizontal line. This implies that it could lose some more water before it reached the point where it was unable to allow any more water to leave the cells.

  1. Marked by a teacher

    Science Coursework: Investigating Osmosis in potato tissue

    4 star(s)

    Then we placed the pieces of potato into their respective solutions and started the test. The following day we took the pieces of potato out of their solutions. We weighed and measured them to see if there had been any osmosis occurring in the solutions.

  2. Marked by a teacher

    Investigation Osmosis in Potato Tissue

    4 star(s)

    In my experiments, the independent variable is going to be the concentration of the sugar solution. The Dependant variable is the variable that I measure. In my experiment there are several dependant variables; the mass, the size of the potato - length/diameter, volume of solution, turgidity.

  1. Marked by a teacher

    To investigate how varying the concentration of sucrose solutions affects the rate of osmosis ...

    3 star(s)

    This meant that the isotonic point of the potato sap had been attained and the concentration of water at both sides was equal. This observation matched the prediction I had made earlier as the isotonic point of the cell sap is greater than 0.125M.

  2. To investigate the factors that effect osmosis in living tissue.

    The length of the cylinder of vegetable used-5cm * The amount of time each vegetable is left in the solution-2 days * The same vegetable used to obtain cylinders since two different vegetables may have been exposed to different surroundings and hence provide us with inaccurate results.

  1. Osmosis is defined as 'the movement of water molecules from an area of high ...

    This is the exact opposite of "turgid". The contents of the potato cells shrinks and pulls away from the cell wall. These cells are said to be plasmolysed. When plant cells are placed in a solution, which has exactly the same osmotic strength as the cells, they are in a state between turgidity and flaccidity.

  2. Find out if osmosis occurs in a potato, and how it affect the potato ...

    There were, I believe, no anomalous results after the experiment as the weights were very similar in their own category. And this tells us that my experiment was successful. The graphs and the results show that: v Osmosis actually took place in the experiment.

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