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

What Factors Affect Osmosis in Potato Cylinders?

Extracts from this document...


. What Factors Affect Osmosis in Potato Cylinders? The aim of this experiment is to investigate the volume of sucrose solution and the weight and volume of other variables which affect osmosis in potato cylinders. In this experiment I will weigh and blot rings of potato and test them in different concentrations of sucrose solution. I hope to find sufficient results as to investigate this. In this experiment I will be investigating, and putting to test, the theory of osmosis. The scientific theory of osmosis is the diffusion of water through a selectively permeable membrane into a more concentrated solution of sucrose. Because the more concentrated solution contains a lower concentration of water molecules, the water flows by diffusion to dilute it until concentrations of solvent are equal on both sides of the membrane. In simple terms, it may also be thought of as the passage of water molecules from a low solution to a high one, across a selectively permeable membrane. (This is shown in the diagram below). Sugar solution Distilled water Sugar molecule water molecule Low High Water Water Potential Potential Selectively permeable membrane Another experiment, published by the author B.S Becket in "Biology-a modern introduction", gives a clear understanding of osmosis. ...read more.


After the rings are cut I weigh each of the 3 potato rings on the weighing scales and write the weights of the rings into my table. I will then put those pieces onto a 6cm long piece of copper wire. They will be placed into a test tube filled with 20cm cubed of sucrose solution. I will place this on the rack, and leave it for 24 hours. After 24 hours, the rings will be weighed again. I will repeat this 6 more times with different concentrations of sucrose solution to see how the weight of the potato rings are affected. (See below for step by step instructions). 1). Use a cork borer to bore a tube of potato out of the potato. 2).Using the scalpel, cut the potato tube into three equal size rings. 3). Using weighing scales, weigh each separate ring of potato and record the weight into the table, (make more than one copy in case the original goes missing). 4). Put the potato rings on a 6cm long piece of copper wire, leaving space between each one. 5). Put the wire with the potato rings on it in a test tube filled with 20cm( of the first concentration of sucrose solution. ...read more.


The second ring was 0.43g heavier than the other two potato rings in the same test tube. The fact that it weighed more before meant that ultimately although it gained exactly the same weight as the other two, it's final weight was still larger. I had to change it's original weight so that my average would make sense. This tells me that the weight of the potato ring does not directly affect the osmosis in the potato ring. This confirms my prediction earlier that it is the concentration of the sucrose solution not the size or weight of the potato ring that affects osmosis. Overall my results seemed accurate enough. They backed up and developed my understanding of osmosis, and seemed to fit in with my theory and scientific knowledge. I could of perhaps taken more time over the cutting of the potato cylinders into rings, and measured my sucrose solution as accurately as I could manage. Although I do not think this would have affected my experiment directly, I t would have made my results clearer and easier to interpret. Of course I could have repeated my experiment for more accurate results, but this was just not possible . I believe I have successfully investigated all the factors I intended to. ?? ?? ?? ?? Thomas Godwin-Coursework ...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)

    Place your quadrat at the first sampling point of 0 metres. 4. Estimate the percentage cover of each plant species that you can find and using the plant species identification card name all the species in the quadrat. 5.

  2. Marked by a teacher

    Investigate the water potential of celeriac.

    5 star(s)

    Average percentage change in mass Highest percentage change in mass Lowest percentage change in mass Range of percentage change in mass 0.0 19.3% 47.8% 8.6% 39.2% 0.2 14.4% 24.3% 2.5% 21.8% 0.4 10.1% 25.9% 2.5% 23.4% 0.6 -1.6% 9.8% -11.5% 21.0% 0.8 -8.5% 7.1% -21.6% 28.7% 1.0 -12.1% 6.3% -23.8%

  1. Marked by a teacher

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

    5 star(s)

    They are therefore, more accurate than using a measuring cylinder. Measuring cylinders are wider and so there is more chance of an error occurring when using these. The syringes used will be of varying sizes so that for different amounts of solution, different syringes can be used.

  2. Marked by a teacher

    Determining the Water Potential of Sweet Potato Tissue

    4 star(s)

    This shows that the changes in the test experiment were due to the factor missing from the control experiment. For example, a sample with no sucrose solution will be a suitable control and just water. In order to get accurate results I will need to ensure a fair test by

  1. Marked by a teacher

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

    4 star(s)

    This can be controlled by submerging all the potatoes in their respective solutions at the same time. Method At first, I will prepare glucose solutions of concentrations 0.25 molar, 0.5 molar, 0.75 molar and 1 molar solution in beakers and label them respectively.

  2. Investigation on Osmosis using a potato.

    When the concentration gradient is lower in the potato, the water will transfer from the solution to the potato. When the concentration gradient is higher on the potato the water will transfer from the potato into the solution. In the distilled water, I believe that the water is more concentrated

  1. Investigate the movement of osmosis through a selectively permeable membrane, in this case potato.

    I then predicted that now I would have to leave the tests for a longer amount of time and use longer potato chips to ensure that there is enough of a reaction to compare them on a graph. I also made some other mistakes which I have to correct, one

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

    � Freeze-dried Brine Shrimp; An entirely natural product and commonly used as a "first food" for developing fry. It is renowned for its high protein and fibre content as well as virtually the same nutritional content as fresh Brine Shrimp.

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