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

The coursework that I have been set is to design an investigation to find out the concentration of sugar solution that causes no real change in mass to a potato chip due to osmosis.

Extracts from this document...

Introduction

G.C.S.E Biology coursework Osmosis PLAN The coursework that I have been set is to design an investigation to find out the concentration of sugar solution that causes no real change in mass to a potato chip due to osmosis. Osmosis is the movement of water molecules through a partially permeable membrane due to a concentration gradient. Water moves from one area with a low concentration to an area with a high concentration. If you place a plant in water, then water will move into the plant cells by osmosis; * The cell membrane of the plant cell acts as a partially permeable membrane. * The cell sap inside the vacuole has a high concentration. * Water passes into the cell by osmosis. * The concentration of the sap in the vacuole is now weaker. * Water passes from the weak solution into the strong solution in the next cell by osmosis. When potatoes are placed into a sugar solution. Osmosis takes place, if a potato is placed into a more concentrated sugar solution, water will move out of the potato and into the sugar solution, this why the potato will get lighter - there is less water in the potato. ...read more.

Middle

The table will look this, concentration start weight (g) end weight (g) % change (M) 1 2 3 average 1 2 3 average 0.25 0.3 0.35 0.4 0.45 0.5 If my results are correct then my graph should look something like this, These are the results that I got from the investigation. concentration start weight (g) end weight (g) % change (M) 1 2 3 average 1 2 3 average 0.25 4.1 3.26 3.26 3.68 4.14 2.92 3.32 3.73 1.36 0.3 4.14 3.21 3.1 3.68 4.12 3.21 3.29 3.67 -0.27 0.35 4.18 3.23 3.11 3.51 4 2.98 3.09 3.36 -4.46 0.4 4.17 3.35 3.05 3.52 3.68 2.91 2.77 3.12 -11.36 0.45 4.14 3.18 3.19 3.5 3.5 2.48 2.86 2.95 -15.71 0.5 1.8 3.35 2.95 3.49 3.47 2.78 2.54 2.93 -16 The results of chip 2 in the 0.25M solution and chip 3 in the 0.3M solution were both anomalous. That is why there is it is shaded in the table. Here are the anomalous results. Concentration Start Final 0.25 3.26 2.92 0.3 3.1 3.29 The first anomalous result loses weight when the other results for that concentration gain weight and the second anomalous result gains weight when the other results for that concentration lose weight. ...read more.

Conclusion

To weigh my chips, I used an electronic scale correct to 2 d.p. but the last decimal place rarely settled and the number continuously changed. I decided to keep it to two decimal places because if the reading I got was 2.23 2.24 2.25 then any one of those readings is more accurate than 2.2 or 2.3. I have already mentioned my two anomalous results, the first anomalous result loses weight when the other results for that concentration gain weight and the second anomalous result gains weight when the other results for that concentration lose weight. This could have happened in a number of different ways, the chips could have more/less surface area so the rate of osmosis is changed, the chips could have been placed in the wrong solution or I could have weighed them incorrectly. Looking at my results, I see that only one of my results gained weight so it might have been better to change the 0.45M and the 0.5M solutions to 0.15M and 0.2M solutions. To improve my results, I should pool them with others to get averages and more accurate results. To extend my investigation, I could look at Osmosis in different plant cells such as carrot or cauliflower cells and I could look in animal cells as well. ?? ?? ?? ?? David Jacques ...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

    Biology Coursework - Osmosis

    5 star(s)

    When the two areas of water are of equal concentration, the areas gain and lose equal amounts of water, so the net water exchange is zero. As the concentration increased further, the osmotic activity did too, dramatically, at 1.5M the percent change was on average 27.98%.

  2. Marked by a teacher

    Photosynthesis Coursework

    4 star(s)

    Set up a lamp at a set distance from the plant, ensuring that this distance is from the filament of the lamp to the actual pondweed, rather than the edge of the beaker.

  1. Marked by a teacher

    The aim of this investigation is to find out how the concentration of the ...

    4 star(s)

    Therefore the potato tubes will all be in their solutions for 20 minutes - although this will not be exact, osmosis is a fairly slow process so the time taken to put them in and take them out will not really affect the results.

  2. Marked by a teacher

    Biology Coursework

    3 star(s)

    Cells Created Sets Where Mitosis Growth, Repair, Replacement 1 Identical 2 Haploid Body Meiosis Gametes (Sex cells) 2 Unidentical 4 Diploid Testes, Ovaries Haploid - 46 Chromosomes (2 sets of Chromosomes) Diploid - 23 Chromosomes (1 set of Chromosomes) - If sex cells were haploid they would have too many chromosomes (92), having diploid cells helps genetic variation.

  1. Osmosis investigation

    In several cases, there is a close agreement within repeats but this is not constant throughout my results. For example, if you look to my results table, at 0.6Molar the first and third repeat are exactly the same. This shows that at points my method of getting results was precise and accurate.

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

    But other than that, there weren�t any bigger matters to be cautious of. Plan I believe this task is very simple and should be very easy to carry out the experiment.

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

    leave them for an hour instead of half an hour to give a greater mass change. I will also be and measuring the mass change as a percentage as it will be more appropriate so that reasonable results could be obtained.

  2. Aim: To find out the effect of altering the concentration of sugar solution on ...

    Overall the preliminary experiment worked according to the plan and the results obtained were also in line with what I expected. Method for Main Experiment Now that the preliminary investigation has been carried out I am in a position

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