• 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...

Introduction

. 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.

Middle

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.

Conclusion

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)

    If the mass is less than previous, repeat step 5 until there is no further loss in mass. 7. Heat the dry soil sample over a roaring Bunsen flame for 30 minutes. 8. Allow cooling until safe to handle and weigh to find the mass of burnt soil (p). 9.

  2. Marked by a teacher

    Investigate the water potential of celeriac.

    5 star(s)

    when the protoplast has no contact with the cell wall at any point. My average results show that this occurs. When the discs are placed in a 1.0 mol dm-3 sucrose solution, the celeriac cells lose 12.1% of their original mass.

  1. Marked by a teacher

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

    4 star(s)

    Later I will plot a line graph to find the molarity. Concentrations Initial Mass (g) Average (g) Final Mass (g) Average (g) Difference (g) Change (%) 1 Molar 0.75 Molar 0.50 Molar 0.25 Molar Water Concentrations Initial Length (cm) Average (cm) Final Length (cm) Average (cm) Difference (cm) Change (%)

  2. Marked by a teacher

    Determining the Water Potential of Sweet Potato Tissue

    4 star(s)

    So the fixed variables are: 1. Volume 2. Time left in solution 3. Temperature 4. Morality 5. Same vegetable used 6. Surface area In this investigation, I am going to calculate ? of the solution inside the cells by working out the molarity of the solution.

  1. Marked by a teacher

    This is an experiment to find out what factors affect osmosis in potato chips.

    3 star(s)

    There fore it will be easier and more accurate to get a percentage change figure. The potato chips will be measured accurately using a top pan balance before the experiment. They will be measured to 2d.p. and then measured a second time after the experiment and then using both figures we will calculate the percentage change.

  2. Investigation on Osmosis using a potato.

    to every point in the graph which conveys there is some trend. As the concentration of sucrose was increased and the water was decreased the potato began to lose mass, and as the concentration of sucrose was very low and the concentration of the water was very high the potato began to gain mass.

  1. The Effect of Sucrose Concentration on Osmosis.

    Surface area also effects osmosis. If a cell has a larger surface area, the rate of osmosis will change due to the fact that osmosis will have to take place in more areas. This is why surface area must be controlled. Another factor that could affect osmosis is temperature.

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

    Time the beetroot is left in the water I am going to control the time that the beetroot is left in the water by using a stop clock. I am going to leave the beetroot in the water for

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