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

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

Extracts from this document...


Osmosis in Potatoes Aim: Investigate the movement of osmosis through a selectively permeable membrane, in this case potato. Introduction: Osmosis is the movement of water through a semi permeable membrane. The water passes from an area of high concentration to an area of low concentration, until the two concentrations are equal in concentrations of water. Many cell membranes behave as semi permeable membranes, and osmosis is a vital part in the movement of liquids in living organisms, for example, in the transport of water from the soil to the roots in plants. If a cell is in contact with a solution of lower water concentration than its own contents, then water leaves the cell by osmosis, through the cell membrane. And if the cell is in contact with a solution of high water concentration than its own then water goes into the cell. If you put a plant cell in water, water enters by Osmosis, then it swells up. However, the cell will not burst. This is because the cell walls are made from something which is extremely strong. Eventually, the cell stops swelling, and when this happens, we say the cell is turgid. This is important, because it makes plant stems strong and upright. Osmosis: Preliminary Work: For my preliminary work, I used 30mm of potato. ...read more.


This is because the solution has more water potential (its molecules' ability to move) than the potato chip, and so water moves from a region of high concentration (the solution) to a region of low concentration (the potato chip.) Method: After having done my preliminary work, I knew exactly which measurements I needed to use in order to obtain the correct results. I set up 18 test tubes, because in order to save time, we intended on doing repeats at the same time as the original experiments were going on. For organization's sake, I set up all of the test tubes at once, and labeled them separately to avoid confusion later on. Into each test tube, I poured just enough Sucrose solution to cover the potato chip, and added one of the potato chips each measuring 50mm in length. In order to make it as much of a fair test as possible, I added the potato chips very quickly, to make sure one chip didn't have a longer amount of time in the solution than another. I then left each one for 25 minutes. After 25 minutes, I emptied each test tube, leaving only the potato chips inside. I then measured the chips in mm because they are a more accurate measurement. ...read more.


The side with the greater amount sucrose molecules will have a greater amount of energy than the other due too the larger amount of molecule on one side. Therefore since the glucose molecules cannot pass through to create a balance the water molecules must. This is the water gradient being balanced. Evaluation: I had a short amount of time to complete the experimenting for this investigation so a planned out my experiments over that time to get them all completed in a short time as possible. If I had the chance I would redo my experiment with more molar ranges, like a range from 0 to 5 as an idea and do each repeat separately as too insure I didn't make the same mistake for all if I did make a mistake. By this I mean I do each repeat on a different day because if on one day 2 molar concentration seems to have been gone off and I did the experiment with out even realizing then all my repeats would give the same result making my results inaccurate and inconsistent. I, after my preliminary work, thought that the amount of solution used was not relevant because it would have no effect of the chips, the reason I did this was also due to the lack of time. If I had time I would go back and measure each solution equally to insure accuracy. ...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

    Investigate the water potential of celeriac.

    5 star(s)

    Join the points with straight lines and determine the molarity at which the percentage change in mass is zero - where the line intersects the x-axis. Using a calibration graph - the x-axis = concentration of sucrose and y-axis = water potential - calculate the water potential of celeriac.

  2. Marked by a teacher

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

    4 star(s)

    * I will label the Petri dishes and beakers so that I do not get confused. * I will cover all the Petri dishes and beakers so as to avoid the formation of fungi in the glucose solution. * I will use 4 different solutions in order to get a range results.

  1. Marked by a teacher

    The Effect Of Temperature On The Permeability Of The Cell Membrane

    3 star(s)

    as it affects the diffusion rate and may give inaccurate and unreliable results. Time for each test made The time for each test made should be kept constant as the amount of time the beetroot is left in the solution does affect the rate of diffusion.

  2. permeability of beetroot membranes

    Alterations to be made: Although the results of the preliminary experiment are pleasing and generally follow my predictions, I will need to make some alterations in order to make it more accurate for my final experiment. The first alteration I will make is to increase the concentration of the glucose

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

    The secondary structure of proteins is the shape of the polypeptide chains. This is because of hydrogen bonding between the oxygen in the -CO group of one amino acid and the hydrogen in the -NH group of another amino acid.

  2. Finding out the affect of different concentrations of sucrose solution on the mass of ...

    My prediction is that when the concentration of water molecules in the potato and in the solution is different there will be a change in mass in the potato chip. The mass will decrease when the concentration of water molecules is lower in the solution than in the potato cells e.g.

  1. Investigating Water Potential Of Potatoes.

    Having done research, I have found a number of things that will effect osmosis, and so are considered as variables, I have already mentioned a few in the research. Firstly, a higher temperature provides more energy to evaporate water and without water, osmosis cannot occur.

  2. Hypothesis: To investigate the effect of different concentrations of ethanol on the permeability of ...

    It is produced naturally by the fermentation of carbohydrates in yeast cells. Industrially, it can be made by absorption of ethene and sub-sequent reaction with water, or by the reduction of ethanal in the presence of a catalyst, and is widely used as a solvent.

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