• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9

An investigation into the effect of Sucrose concentration on osmosis

Extracts from this document...


AIM: The aim of my experiment is to investigate the effect of sucrose solution on osmosis in potato cells, and what the point of equilibrium would be. I shall be observing how the mass of the potato chip changes in five different concentrations of glucose solutions. HYPOTHESIS: Osmosis is the diffusion of water molecules from a high water potential to a lower water potential through a partially permeable membrane. A partially permeable membrane, such as a cell wall, allows small molecules, such as water molecules, pass through it, but does not let bigger molecules such as sucrose through it. Cells placed in distilled water take up water by osmosis. This happens because the cell contains dissolved chemicals and therefore has a lower water potential than the distilled water surrounding it. As there are more water molecules outside the cell, more go in to the cell than out of it. The net movement of the water molecules is into the cell, and the cell will increase in mass. Eventually the cell stops taking up water, even though the concentrations inside and outside are not even. This is because the cell wall becomes stretched and prevents any more water entering. The cell is said to be turgid. Cells placed in a concentrated sugar solution lose water by osmosis, as the water potential is higher inside the cell. As there are more water molecules inside the cell, more water molecules leave the cell than enter it. The net movement of the water molecules is out of the cell. ...read more.


Lastly, I shall use the same volume of solution for each test tube. The potato cylinders must be totally covered in the solution, and the amount of solution will be kept the same, as all the potato cylinders are the same size. In my pilot study, I found that 20cm� of solution is a suitable amount for this experiment. This is because 10cm� of solution only just covered the potato cylinder, whereas 20cm� covers it fully and has space left over. This number is also easy to make solutions of different concentrations from. I chose to do these concentrations of sugar solution: 0.0M 0.7M 0.2M 1.0M 0.5M This is because in my pilot study, I found that my point of equilibrium was close to when the concentration was 0.2M. I tried to make my concentration fairly evenly spaced, so that I would get a good line on my graph. The mass of the potato cylinders is a dependent variable, and this means that it will be measured throughout the experiment. I will measure the mass in grams, measuring to 2 decimal place, using a digital balance so my results will be precise. The potato cylinder will be weighed before it is put into the solution, and after. This will allow us to whether osmosis has taken place, and to what extent. To make my experiment as reliable as possible with the amount of time given to carry it out, I shall repeat this experiment once and use the average of these results for my graph. ...read more.


* I cut all the potato cylinders uniformly with an apple corer, therefore all the side were the same length. * I left all of the potato cylinders in their test tubes of sugar solution for exactly 25 minutes each; therefore they all had the same amount of time for osmosis to take place. * I used the same volume of solution for each test tube. Some further work I could do to help me find out more exactly what the point of equilibrium is, is to do this experiment again, however instead of measuring the increase or decrease in mass of the potato, I would measure the change in length of the potato cylinder. Then I would plot the results for that experiment on the same graph I drew for this experiment. Hopefully, the point of equilibrium would pass at the same point on the x-axis, however if it didn't, I would average out the two points of equilibrium and use that answer for my point of equilibrium. Table of Results Concentration (M) Try 1 Try 2 Average % change in mass Mass before (g) Mass after (g) Change in mass (g) %Change in mass (g) Mass before (g) Mass after (g) Change in mass (g) % Change in mass 0 5.46 5.62 0.16 2.93% 5.26 5.48 0.22 4.18% 3.56% 0.2 5.45 5.52 0.07 1.28% 5.27 5.34 0.07 1.33% 1.31% 0.5 5.36 5.28 -0.08 -1.49% 5.36 5.3 -0.06 -1.12% -1.31% 0.7 5.37 5.2 -0.17 -3.17% 5.14 4.94 -0.2 -3.89% -3.53% 1 5.41 5.16 -0.25 -4.62% 4.97 4.69 -0.28 -5.63% -5.13% Aditi Gupta LVM ...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

    Investigating the effect of sucrose concentration on osmosis in potato cells

    4 star(s)

    I have chosen these concentrations because they are wide-ranged and equal distances part, which makes it easier to plot them on a graph and identify trends. It will also be easier to find, using the graph, the approximate concentration when the percentage change in mass crosses the x-axis, when the

  2. Marked by a teacher

    Experiment to find the effect of sucrose solution concentration on potato and apple tissue.

    4 star(s)

    (Britannica Encyclopaedia) The more concentrated the solution, the lower its water potential will be. Adding pressure to the solution will increase its water potential In solutions, the X of the solution = the Xs In a Plant cell the X of the cell = Xs + Xp When the potato

  1. Osmosis, What is the effect of sucrose concentration on the rate of osmosis in ...

    Surface Area: This is the greatest cause of harm to the results. I removed the potato skin successfully and cut the tubes to the correct length. However, I had some problems with the corer. After eleven tubes, there was hardly enough space for one more.

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

    My theory in this experiment is that, due to the difference in the water concentrations of the two substances, I believe that the weight of the potato will start decreasing when it is tested on 0.2 molar solutions of sucrose and greater.

  1. Osmosis Investigation

    - I will use graph paper in order to measure the exact length of the potato tubors. - I will use a weight scale to record the mass of the potato tubors. - I will use distilled water as the hypotonic solution, which will be stored in its corresponding beaker.

  2. Factors Affecting Osmosis.

    The graph shows that the potato cylinder in distilled water (0.0m sucrose solution) increases in mass while all the remaining potato cylinders steadily decrease in mass as the concentration steadily increases. However if the limiting factor 'each potato chip has only a certain volume of water to loose' does begin

  1. Osmosis. To investigate which sucrose concentration is the same as the concentration of cell ...

    To make sure our results were reliable we repeated this experiment three times in exactly the same conditions (temperature etc.)

  2. Osmosis investigation

    -1x Calculator -2x Kitchen towel -12x White labels (6 for labelling boiling tubes, 6 for labelling bundles of potato chips) -Clingfilm -2x measuring cylinder (0-25ml3) Method: 1. Get the potato measuring equipment for the potato (cutting tile, scalpel, cork borer etc), including potato.

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