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

Osmosis in Potatoes.

Extracts from this document...


Osmosis in Potatoes Osmosis is a special type of diffusion where water moves across a semi permeable membrane from an area of low solute concentrating to an area of high solute concentrating. Osmosis is an important in plant cells as it makes the cell turgid. Turgidity is when no more water can enter the cell and therefore helps to keep the plant firm and upright. Variables: Some parts of the experiment will have to be kept the same while one key variable is changed. Some of the variables I am going to control are: * Time left in solution - If the chips were left longer in the solution than others, more time would be allowed for osmosis to occur. * Surface area of potato chip - If the surface areas are larger on some chips than others there would be larger and there would therefore be more space for osmosis to happen. I have chosen to change the concentration of the sugar solution. If any of the non-variables aren't kept constant it would mean it would not be a fair test. ...read more.


so we could easily work out the percentage of liquid. 6. We then placed three of the potato chips into each of the test tubes and put a bung on top. 7. We left the chips in the concentration for 24 hours for the osmosis to occur. 8. The next day we emptied the test tubes in a sieve and measured each chip from each solution. Prediction: I believe that the more Sucrose solution present in the test tube the smaller the chip will be. This is because water diffuses from the chip through the semi permeable membrane and into the sucrose solution because it has a lower concentration of water. So when loads of the water has diffused from the chip it will shrink and will no longer be turgid instead it will become flaccid. Flaccid is the exact opposite of "turgid", instead of the cell-becoming firm it becomes soft and limp. Aim The aim of this experiment is to investigate the movement of water into and out of plant cells by osmosis. ...read more.


This is because the cell is fully turgid and no more water can enter it. At point B (100% Concentration of Sucrose Solution), the cell is not decreasing any further in size. This is because the cell is fully plasmolysed and no more water can leave the cell. (Plasmolysed is when a plant cell loses water and the vacuole shrinks. The cytoplasm and membrane shrink away from the cell wall. This is a plasmolysed cell.) Evaluation: The results we got from the experiment were reliable and fitted a clear pattern. Though I believe if we were to have done the experiment again with more chips and a bigger variety of dilutions like 10%, 20%, 30%, 40% etc. then we could have got more exact results. Also when controlling variables if we had controlled the temperature then the experiment would have less chance of mistakes and anomalies, as having a different temperature in one test tube than another will change the rate of osmosis. When measuring the chips we could have got more exact results by using a Vernier Calliper as this measures to the closest 0.1mm and would therefore give a more accurate measurement giving us more exact results. ...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

    Osmosis. Aim: To find the molarity of potato tubers cell sap. BIOLOGICAL ...

    4 star(s)

    The highest negative change of -10.00% was in 1 molar solution followed by 0.75 molar which was -7.33%, 0.50 molar which was -4.00% and 0.25 molar which was -0.67%. Water, as expected gave me positive change of 5.83% and so I got a positive bar. They are all scientifically correct.

  2. Investigating osmosis on swede cells.

    1st 2nd 3rd Average 0 6.66 13 3.33 7.6 0.2 3.33 -3.33 0 0 0.4 -3.33 -6.66 -6.66 -5.55 0.6 -6.66 0 3.33 -1.11 0.8 -3.33 -3.33 -10 -5.55 1 -10 -13.3 -13.3 -12.2 Analysis: From the graph plotted to show the relationship between concentration and the percentage change of

  1. Investigation on Osmosis using a potato.

    This is so that we do not get a false reading, with the weight of our potato with the reading it had before which may lead us to the wrong conclusions. After the experiment, we will measure the 3 potatoes that should be dried as much as possible, and weigh

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

    Moreover I think that the pigment will be transported by diffusion, and the rate of diffusion also increases with temperature. Therefore I predict that the temperature at which the pigment will start move is about 40�C. However I think that at 60�C the membrane will have completely broken, therefore all of the pigment will have got through the membrane.

  1. To Investigate the Effect of Osmosis on Equal Length Potatoes

    Preliminary Results Length Of Potatoes = 4cm Mass (g) Molars Before After 1M 3.32 3.18 0.75M 3.26 3.24 0.5M 3.36 3.39 0.25M 3.38 3.47 0M 3.34 3.58 Apparatus The apparatus I shall be using in this experiment are as followed; * 5 Test tubes (to hold the sucrose and potatoes)

  2. effects of concentrations of sugar solutions on potato chip cells

    At this point osmosis stops. I carried out some preliminary work to help me with my plan. I tried using a boiling tube to hold my chips and solution in, using 20ml of solution in total. I used an accurate 25ml-measuring cylinder, which I could keep to the nearest ml.

  1. Investigating Water Potential Of Potatoes.

    High osmotic pressure NET MOVEMENT OF WATER MOLECULES After looking at diagram 1 and the previous information given, you will appreciate that there will be net movement of water molecules from the left of the selectively permeable membrane to the right.

  2. This experiment aims to investigate the effects of 4 different types of fish food ...

    Protein is split into amino acids by hydrochloric acid and the enzyme pepsin present in the stomach. Protein undigested in this way is then broken down by enzymes such as trypsin in the intestine.These are then used to allow the fry to develop muscle mass and enzymes etc.

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