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

GCSE Biology Osmosis Coursework

Extracts from this document...

Introduction

GCSE Biology Osmosis Coursework Introduction Osmosis is the movement of water molecules from a week solution to a strong solution through a semi-permeable membrane. The key factors of osmosis are concentration, surface area and temperature. In my experiments I will be changing the concentration of the water. Aim To investigate what speeds up the rate of Osmosis. Preliminary Work In my preliminary tests I started by setting up the apparatus as in the diagram above, then I started to gather results from the preliminary experiments. Concentration (M) Mass before (g) Mass after (g) 0.0 pure water 0.67 0.74 0.25 0.8 0.87 0.5 0.7 0.84 1.0 1.08 1.09 From these results I will make up a method that will show better results in my experiment. I have also decided that I will use smaller concentrations in my experiment and will do each test twice, this is so that I have a better chance of good results. Planning Method For my experiment I will need to cut a bit of potato into near equal sized chips with a near equal mass, and then I will put ...read more.

Middle

Whereas when the concentration is in the middle strength region, 0.3, 0.4, then the chips will start to keep the same weight because the sucrose concentration will star to equal out. Also I think that when the concentration is high, 0.5, the chips will start to loose weight because the sucrose concentration will be higher out side of the chip. I think that the texture and strength of the chips will change as well; I think that when the concentration is low that the chips will stay strong or get stronger due to gaining mass, then when the concentration is In the middle then the chips will get softer and when the chip is in high concentration the chip will be soft and flexible. I think that when the concentration is the lowest then the speed of osmosis will be at its fastest because the concentration outside the chip will be weaker than inside the chip allowing osmosis to be quicker. Obtaining Evidence Results 1 2 3 4 5 6 Concentration (M) ...read more.

Conclusion

Osmosis occurred fastest in the 0.1 Molar sucrose solution, this happened because the solution was quite week allowing it to pass through a semi-permeable membrane in the chip due to the high concentrated solution inside the chip. Evaluation By doing this experiment I was able to show the effect of concentration of sucrose on the speed of osmosis, this is shown in my results. Most of my results are as accurate as I think I could have got them, however there are a couple of results on the mass after where the mass after drops bellow the mass before at a weak concentration. These anomalies where probably caused by an increase in temperature or a slightly stronger solution than with the other results. If I did the experiment again then I would do each concentration more than twice, probably three or four times each, this would give me a much more accurate set of results because I would get a much more accurate average and I would have enough results to ignore any anomalies. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Exchange, Transport & Reproduction 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 AS and A Level Exchange, Transport & Reproduction essays

  1. Marked by a teacher

    Sand Dune Succession Coursework

    5 star(s)

    levels of pH and humus in the surface layers of the dunes aswell as the plant diversity. I feel these factors will produce reliable and precise results that will show clear trends when analysed by using a plant species identification card, the reliability of results is greatly improved as the

  2. Marked by a teacher

    Biology coursework planning - the effect of lead chloride on the growth of cress ...

    5 star(s)

    A stable environment was required and a number of different mediums were considered in which the cress seeds could be grown. These included a cotton pad, cotton wool, filter paper, sponge and soil. The sponge was rejected because of its excessive water holding capacities which would deprive the cress seeds of water and therefore allow insufficient growth.

  1. Investigation on Osmosis using a potato.

    These will be 4 mm long it will depend on the size of the potato because we will need to use one potato only so they may be smaller or bigger than this. 5. We will also need a calliper again to measure the surface are of the top of the cylinder to make sure they are roughly the same.

  2. AS biology coursework on enzymes

    of starch and distilled water to make it a blue/black colour and then once my amylase has been added I will start the stopwatch and wait for a colourless solution. I will know that a clear solution has appeared because I would have drawn a black cross on a white tile and held it up against the solution.

  1. Potato coursework

    When an animal cell is placed in a hypertonic solution the cell will gain water, swell and then burst. However when placed in a hypotonic solution the cell shrinks as it looses water. In plant cells, when placed in a hypotonic solution, water enters causing the volume to increase meaning the pressure inside the cell also increases.

  2. Design an experiment to investigate the effect of temperature on the movement of a ...

    Finally the temperature affects the rate of diffusion, as the temperature increases the rate of diffusion increases proportionally. This is because when heat is given to the molecules this is converted into kinetic energy so the molecules move around faster.

  1. Finding out the affect of different concentrations of sucrose solution on the mass of ...

    I used sucrose concentrations of 0% and 25% and put 30cm3 of each in a specimen tube. Then I cut 3 potato chips with a cork borer and made each chip 4.5cm in length. I blotted excess water off with a paper towel and weighed them on a top pan balance.

  2. Evolution and Biodiversity - Edexcel GCE Biology Revision Notes

    - Overtime, the number of individual with the advantageous adaptation increase and over generations, this would lead to evolution as the favourable adaptation become more common in the population. * That was the Charles Darwin?s theory of evolution by natural selection.

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