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

To Investigate the Movement of Osmosis Through a Potato Sample.

Extracts from this document...


Osmosis Aim: to investigate the movement of osmosis through a potato sample. Hypothesis: Osmosis is the movement of water through a semi permeable membrane, separating solutions of different concentrations. The water passes from a region of high concentration to a region of low concentration, until the two concentrations are equal in concentrations of water. 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. Water is lost first from the cytoplasm, then the vacuole through the tonoplast. The living contents of the cell contracts and eventually pulls away from the cell wall and shrinks, this is known as Plasmolysis. If you put a plant cell in water, water enters by Osmosis, then swells up. However, the cell will not burst. This is due to the fact that the cell walls are made from cellulose, which is extremely strong. Eventually, the cell stops swelling, and when this point is reached, we say the cell is turgid. This is important, because it makes plant stems strong and upright. Osmosis diagram: I predict, that as concentration increases, the weight of the potato will decrease. ...read more.


For organisation's sake, we set up all of the test tubes at once, and labelled them individually to avoid confusion later on. Into each test tube, we poured 15mls of Glucose solution, and added one of the potato chips, each weighing around 1 gram, and measuring 33mm by 5mm. In order to make it as much of a fair test as possible, we added the potato chips very quickly, to make sure one chip didn't have a longer amount of time in the solution than another. We then left each one for 30 minutes. After 30 minutes, we emptied each test tube, leaving only the potato chips inside. Before we measured and weighed each chip, we dabbed them with paper towel. If we had of left excess water on the chips, the weights would not be accurate. We then measured the chips in mms because they are a more accurate measurement. Results Analysis Of Graphs: * Graph 3 'Average change in weight' is quite confusing. For example, the result I obtained for 0.1 molar concentration does not follow the pattern of the other results. It is not possible that the weight could have gone up more for 0.1 molar concentration, compared to 0 molar. This could be due to having excess water on the potato chip when weighing or because of misreading the scales. Conclusion: To conclude this investigation, I can say that the movement of water through a selectively permeable membrane is affected by concentration of glucose solution, or by any other solution. ...read more.


When weighing the potato chips after 30 minutes in solutions, it was inevitable that they would have excess water on them, and so we dabbed them with paper towel to remove it. However, in doing this we could have removed water that was not excess, and altered our results. Another inaccuracy was when we put the potato chips into the solutions, because it was impossible to not leave a small interval between each test tube. The first test would have been going for a few seconds longer than the last. I do not know how I would resolve this problem. I also found 2 anomalous results. The first, was on the graph which showed average change in width, the anomalous result was for the test for 0.2 molar solution. The second was on the graph that showed average change in weight, the anomalous result was for the test with 0.1 molar concentration. The main reason for this is inaccuracy. I used the mean when plotting my graphs. That way, the information is clear and can be understood quickly, however, the disadvantage of this, is the fact that if one of the two results is inaccurate, the mean will also be. I believe that this is the reason for the anomalous results. I could extend this AT1 by investigating osmosis with a different factor as opposed to concentration of water. I could investigate the effects of temperature on osmosis, or surface area. This would give me a very clear understanding and knowledge of osmosis in potatoes. ...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. To investigate the movement of osmosis through a potato sample.

    This is because the solution has a greater water potential (its molecules' ability to move) than the potato sample, and so water moves from a region of high concentration (the solution) to a region of low concentration (the potato sample.)

  2. The aim of the investigation is to investigate the movement of water in and ...

    o A razor blade is required in the experiment so you must take care as it could cause a serious wound. You must carry the knife facing downwards. You must also always use it on a tile to avoid damaging the bench.

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

    The thickness of the chip will already be the same, so I will cut the length so that each chip is 3cm long. To make the mass readings more fair, I will take each chip of the solution, roll all the surfaces gently on a paper towel, (2 seconds on

  2. Osmosis, Aim: Investigate the movement of osmosis through a selectively permeable membrane, in ...

    However, in the middle of the scale, say 0.2 molar concentration; the graph will go right down, due to the fact that the solution will be isotonic to the potato. In other words, the solution and potato chip are about equal in concentration.

  1. Osmosis, Aim: To investigate the movement of osmosis through a selectively permeable membrane, ...

    have all been cut without being washed and peeled. - The mass of the potato is a dependent variable, and this means that it will be measured throughout the experiment. I will measure the mass in grams. The potato chip will be measured before it is put in the solution, and after.

  2. Structures and functions in living organisms. Revision Notes

    This transportation only occurs in one direction. 2.53 Explain how water is absorbed by root hair cells Root hair cells have a large surface area - extension + hairs. Water enters the root hair cells via osmosis. This increases water potential in root hair cells, compared to the cells nearby, so water moves to these cells via osmosis etc...

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