• 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)

    2.06 2.11 1.93 1.94 1.80 1.76 1.99 1.92 Shown on the next page are line graphs of the results. I have used the average results to make the graphs easier to understand. Conclusion From looking at my results graphs, I can see a clear pattern in that the length and

  2. Marked by a teacher

    Biology Coursework

    3 star(s)

    Hayflick Limit - cells have a limit to number of times they can divide. Humans limit is 52. Stem cells (cells that embryos have) and cancer cells have no Hayflick limit. Differentiated cells - cells that have been specialised so they can do a specific job (cells differentiate in embryos so that it can develop organs and body)

  1. Marked by a teacher

    Biology Coursework - Osmosis

    3 star(s)

    I will use three pieces of potato in each petri dish of each solution in order to give more reliable results. For each petri dish I will use 50ml of solution in order to keep it a fair test. Pilot Test: I decided that before I carried out my investigation,

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

    The investigation is very straightforward. There won�t be any control for this experiment, because the weight would vary depending on the potato pieces. And therefore, it might affect the results, which we are going to take in after the experiment.

  1. Osmosis Chip Investigation

    will be dabbed with a paper towel to remove excess water before weighing as this prevents water that is merely resting upon the surface of the chip and has not been absorbed as if that water was left on the chip inaccurate readings would be taken.

  2. Osmosis investigation

    This is because after plasmolysis, the cell is not capable to retain water and therefore osmosis cannot occur. This leads to a curved shape in my graph. Evaluation: Anomalies: Due to the presence of anomalies in my data, the data cannot be classed as reliable.

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