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

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

Extracts from this document...

Introduction

Osmosis Investigation Aim: To Investigate Osmosis in potato cell using different concentrations of sugar solutions. Scientific Knowledge: Osmosis is the diffusion of water molecules from a region high water concentration to an area of low water concentration through a semi permeable membrane. Thus equalizing the conditions on either side of the membrane. A semi permeable membrane is a very thin layer of material -cell membranes are also semi permeable membranes- which allow small molecules including oxygen, water, carbon dioxide, ammonia, glucose, and amino acids to fit through (pass through) the little gaps in the membrane and prevent bigger molecules like sucrose, starch, protein passing through because the are to big to fit through the gaps. A region of high water concentration is a very dilute solution of sugar or just pure water where there is lots of water molecules causing a high water concentration. Whereas an area of low water concentration is an area with very few water molecules like in a very strong sugar solution because there are more sugar molecules than water molecules. If you place potato strip in pure water then they could become turgid this means the potato strip will become firmer and swell up. This happens because water molecules have distributed themselves from a high concentration around the potato to a low concentration in the potato cells(endosmosis), thus making the water molecules equal on both sides of the potato membrane and making the potato turgid. This will stop when the water is equal in the potato and in the solution. ...read more.

Middle

I will achieve this by keeping a water bath nearby. I must also make sure that the potato strips are in the solutions all for the same amount of time. Which will be 20 minutes each beaker. This will be kept to using a stopwatch. This could affect my investigation because if the strips are in longer or for a shorter time the results won't be reliable. This is because more or less osmosis could occur in different strips. The size of the potato strips must be as equal as I can make it. I will measure each strip making sure that they are all 30mm although I would rather have weighed them on a scale. Unfortunately I didn't have one. This is a factor to control because when I take them out of the solution and measure them I will not now how osmosis has affected the potato strip because the length wasn't the same as the rest when it went into the solution, so the rate of osmosis or the difference between each strip will not be reliable. I must make sure that none of the solutions are contaminated with anything apart from the amount of sugar dissolved into the right beakers. This may happen while mixing the solutions if the same mixing instrument is used or if a little bit of sugar spills into the wrong beaker or even if I accidentally mix the solutions up. So to prevent this I will have the beakers marked and will not put anything in the beaker if it has been in a different beaker already (when I measure the temperature I will wipe the thermometer clean first) ...read more.

Conclusion

* Make sure all temperatures are between 23-24�C * Core a potato * Using the cored pieces cut 18 disks that has a circumference of 20mm * I will place 3 into the first beaker while starting a stopwatch. * As soon as the stopwatch shows 10 minutes I will place three more disks into the second beaker * Upon doing this I will restart the stopwatch * When 10 minutes is again shown on the stopwatch I will restart the stopwatch. * At this very time I will remove the first three potato disks from the beaker and measure them. I will enter the results into the table. * I will also put three more disks into the next beaker while doing the previous two steps. * I will then repeat the last six steps until I get 18 results from six different beakers, noting them down as I go along. Results Length of Potato Strips after 20 minutes (mm) Solutions Strip 1(mm) Strip 2 (mm) Strip 3 (mm) Temp. (�C) Average (mm) Pure Water 19 20 20 24 20 10% 17 17 18 23 17 20% 17 16 17 23 17 30% 16 17 16 23 16 40% 15 16 15 23 15 50% 15 15 16 23.5 15 Each potato strip was 20mm at the start. Solutions Size of potato at start (mm) Average size after 20minutes (mm) Increase or decrease (mm) Pure Water 20 20 0 10% 20 17 -3 20% 20 17 -3 30% 20 16 -4 40% 20 15 -5 50% 20 15 -5 Note: all results have been rounded up to the nearest mm ...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. My aim for this experiment is to see the results of potato tissue's mass ...

    will start decreasing when it is tested on 0.25 molar solutions of sucrose and greater. Scientific explanation of what would happen: Osmosis is defined as the movement of water molecules from an area of high water concentration to an area of low water concentration, across a semi-permeable membrane.

  2. Free essay

    Aim and background knowledge: - To investigate how different concentrations ...

    and recorded this information in a table. From completing this work, I have learnt that not only the mass is important when making investigations such as these fair tests, but also the surface areas of the samples used should be taken into consideration. This is because, when the surface area is larger, the diffusion of water molecules through the plant cells increases, and so osmosis increases.

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

    1.51 1.15 -0.36 -23.841 5 1.63 1.68 0.05 3.06748 6 1.34 1.39 0.05 3.73134 average 1.55 1.48833 -0.0616 -4.0053 0.5m concentration mass before (g) mass after (g) change in mass (g) % change in mass 1 1.65 1.45 -0.2 -12.121 2 1.66 1.52 -0.14 -8.4337 3 1.88 1.71 -0.17 -9.0425

  2. What is the concentration of sugar in potato cell?

    When there is a great change in the pattern of the results between two solutions then the concentration of the potato tuber before the experiment will be between those two concentrations. From the trial run, I predict that the concentration of the potato will be between 0.2 and 0.4 molar,

  1. osmosis. I predict that when the experiments takes place, the potato strip in the ...

    However, the potato strips in the beakers with low sugar concentration will gain mass. I have given more information below on why I think my prediction is correct. The smaller quantity and concentration of water in the outer solution means the larger amount of water will leave the potatoes cell.

  2. In this coursework I am going to investigate the factor how different concentrations of ...

    A turgid cell is a cell that is swollen and hard. The pressure inside the cell rises and eventually the internal pressure of the cell is so high that no more water can enter the cell. This liquid or hydrostatic pressure works against osmosis.

  1. Experiment to see the results of potato tissue's mass difference, when placed in different ...

    I plan to have use glucose as the sugar solution prepared with concentrations from 0.1M to 1.0M, in intervals of 0.2. Then sections of potato will be cut using a cork borer number 5 and knife to equal lengths (5cm)

  2. Potato tissue's mass difference, when placed in different concentrations of sugar solutions.

    And therefore the weight should decrease, at least noticeable for us to notice. The difference between the water concentration in the potato and the 0.8 molar solution of sucrose is big, and the water in the potato should be transferred from the potato, through the permeable membrane, to the solution surrounding the potato.

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