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

Properties of an Artificial Membrane: Diffusion and Osmosis

Extracts from this document...

Introduction

Properties of an Artificial Membrane: Diffusion and Osmosis Purpose- Is to gather enough evidence to prove that osmosis and diffusion occur in these types of membranes, this is done by using a selectively permeable membrane called dialysis tubing. Hypothesis- Osmosis and diffusion will continue until equilibrium is reached and net movement will no longer occur. Solute size and concentration gradient across the selectively permeable membrane will effect diffusion. Materials- please refer to transport across semi-permeable membranes: diffusion and osmosis laboratory exercise hand out. Procedure: please refer to transport across semi-permeable membranes: diffusion and osmosis laboratory exercise hand out. Observations: Table A: Time Dilute Lugol's solution in beaker Glucose and Starch solution in dialysis tube Initial Observations Clear yellow solution/ color changed into blue Clear After 10 minutes More yellow than before/ reacted with ...read more.

Middle

The iodine diffused through the tubing, but the molecules of starch/glucose solution were too large to diffuse through the tubing. Iodine, which is a fluid and has very small molecules, was able to diffuse through the dialysis tubing and reach an equilibrium on the inside and outside of the tubing. This is proven by the increase in the size of the tubing from the initial mass of 14.66 g to a final mass of 15.74 g. However, sucrose and starch are macromolecules, so they were too large to diffuse through the tubing. This was proven by the benedicts test of the outside area, it came up negative, while the test of the tubing fluid came up slightly positive. ...read more.

Conclusion

Another possible source of error would be not leaving the solutions for the amount of time required, possible way to improve this would be keeping a watch nearby at all times. Ways to improve this lab would be to add more than 5 drops of Lugol's Iodine solution to the distilled water, therefore a more vivid observation could be recorded. Another way to improve this lab would be to extend the time of observation and then that would give time to collect clear and more accurate evidence. Conclusion: Osmosis is the diffusion of water molecules through a selectively permeable membrane from an area of higher water concentration to an area of lower water concentration. Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration. ?? ?? ?? ?? Etran Bouchouar 5/1/2007 ...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

    The Effect Of Temperature On The Permeability Of The Cell Membrane

    3 star(s)

    I could have let the stop watch run a bit over the time or under the time and so the beetroot may not be taken out at the exact time. This could possibly indicate that as the beetroot was left in the heated water for a longer period, more pigment could have leaked out.

  2. Peer reviewed

    The comparison of antibacterial properties of herbal products and standard antibiotics

    5 star(s)

    Variables and controlling the variables: To ensure the results are accurate much attention should be paid to producing a fair test by controlling the variables. The independent variable throughout this experiment is the product being used, so either penicillin, streptomycin, tea-tree oil or peppermint oil.

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

    concentration, until the concentrations of both regions are equal, creating a dynamic equilibrium. The pigment would be transported through the membrane by diffusion because the concentration of the pigment in the vacuole would be greater than the concentration in the cytoplasm, as there is no pigment there.

  2. Diffusion and Osmosis: Investigating the Processes of Diffusion and Osmosis in a Model Membrane ...

    An example of diffusion is opening a bottle of H2S in a corner of a room. After a few minutes, the opposite side of the room would smell the H2S (the smell of rotten eggs). The reason for this is because the bottle has a higher concentration of H2S molecules

  1. The sensitivity of the Benedict's Test-Investigation

    2.07 0.29 0.11 0.07 Average 5.1325 2.725 0.4425 0.0975 0.065 Graph Conclusion Concentrations of glucose (%) Colour present after heating with Benedict's solution 10% Dark orange 1% Light brown 0.1% Green blue 0.01% Marine blue 0.001% Blue From this table you can see that the 10% glucose solution had the

  2. To investigate the movement of osmosis through a selectively permeable membrane.

    To begin, we used 15mls of Glucose solution- this was the amount needed to cover one piece of potato. The first thing we needed to observe, was how different concentrations affected the weight and length of the potato. We therefore needed to observe each end of the spectrum.

  1. Investigation on Osmosis using a potato.

    This basically may be the fact that this potato was different to the others and probably could not be avoided. In this test there is only one point which hits the line of best fit perfectly and this is the solution: * 21 ml sucrose solution + 9 ml distilled water (0.7 Molar)

  2. permeability of beetroot membranes

    We decided to measure how changing the concentration of the glucose solutions affected the rate at which osmosis takes place in potato tissue. Our controls for this experiment were the amount, size and shape of potato, the apparatus used and the volume of solution used for each concentration.

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