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

In this experiment we are going to be studying the affects of Osmosis in Potatoes. Osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration.

Extracts from this document...

Introduction

Background In this experiment we are going to be studying the affects of Osmosis in Potatoes. Osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration. A semi-permeable membrane is a very a very thin layer of material, cell membranes are semi-permeable. These will allow some things to pass through, but will prevent other things from passing through. For example, cell membranes will allow small molecules such as Oxygen, water, Carbon Dioxide, Ammonia, Glucose, amino acids, etc. to pass through. But they will not allow larger molecules such as Sucrose, Starch, and protein, etc. to pass through. A region of high concentration of water is either a very dilute solution of, for example, sucrose, or Pure Water. In each case there is a lot of water: there is a high concentration of water. A region of low concentration of water is a concentrated solution of something, for example, sucrose. ...read more.

Middle

I am going to have 6 different test tubes which will have the same volumes but different concentrations. These concentrations will be diluted water, 0.2M, 0.4M, 0.6M, 0.8M and 1.0M. Method I started off getting a large potato. Using a cork borough I removed 12 sections of Potato, I used the cork borough on a tile and kept my hands well away from it so I would not cut myself. I then cut these sections down using a razor blade on a tile so they were all 4 cm long; I measured this using a ruler. I used the razor blade with precaution, taking into account that it was sharp and making sure I did not cut myself. After this I weighed each individual section on a weighing machine, this scale measures down to 0.00g. I then got 6 test tubes and filled them with different concentrations of salt solution; each test tube had a 30cm volume of liquid. ...read more.

Conclusion

Because there is more water in the cells than in the solution, more water is going to pass through the cell membrane from the cells than pass though in to them. Therefore the cells will shrink and the overall mass and size of the potato section will decrease. The larger the concentration of the salt solution the larger amount of water will pass from the cells into the solution; this is why the cells decrease in size the larger the concentration. Earlier Work While in the forth form I did work on Osmosis. The experiment helped me out a lot with the understanding of Osmosis. In the experiment a high concentration of salt solution is put into some dialysis tubing, which is a semi-permeable membrane. The tubing is tied up and placed into some Distilled water. It is left for a few days, and when we came back, the distilled water is tested and it is now a low concentration of salt solution. The text book GCSE Biology second edition by D.G. Mackean also helped me with my understanding of Osmosis. ...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 Molecules & 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 AS and A Level Molecules & Cells essays

  1. DETERMINING THE WATER POTENTIAL OF A POTATO TUBER CELLS USING THE WEIGHING METHOD.

    Cells that are flaccid or plasmolysed (right) have a pressure potential of zero FIGURE 4 (LEFT) A TURGID CELL AND (RIGHT) PLASMOLYSED CELL4 SOLUTE POTENTIAL ?? is the solute (chemical) component: pure water will flow from where it is in high concentration (i.e. dilute solutions) to where it is in low concentration (i.e.

  2. An experiment to find of the isotonic point of root vegetables cells in contents ...

    Then remove the McCartney bottle lids and place them on the side. 5. Using the sucrose pipette measure 6ml of sucrose and add it to the 0.30 molar sucrose labelled McCartney bottle with Parsnip, using the water pipette measure 14ml of water add to the same McCartney bottle. 6.

  1. Investigating Osmosis.

    to 0.4 molar (which would again be enough to plasmolyse the cells). We then place each of the sets of three cylinders on a pin into each of the different solutions, making sure that the cylinders are covered by the solution, and leave all of the test-tubes close to each other for 24 hours.

  2. Biology Osmosis Plan

    To summarise, I believe that the more concentrated the solution the less mass the potato will have at the end of the experiment. The less concentrated solution then the more mass the potato will have at the end of the experiment.

  1. Osmosis is the passage of water from a region of high water concentration through ...

    When animal cells are placed in sugar solutions things may be rather different because animal cells do not have cell walls. In very dilute solutions, animal cells swell up and burst: they do not become turgid because there is no cell wall to support the cell membrane.

  2. Biology GCSE Definitions

    Endocytosis - phagocytosis bulk uptake of material by a vacuole - pinocytosis bulk uptake liquid Excotosis is the secreting of material out of the cell. (INSERT PICTURE OF LUNG) Blood with low o2 and high co2 is brought to the alveoli, and so diffusion occurs.

  1. Investigating Osmosis.

    This is when the cell becomes firm and rigid. This is when it's turgid (cell is fully expanded. Like a blown up balloon) A cell is only turgid if the cells external medium is more watery than the fluid in the cell's vacuole such as pure water. The expanded turgid cells in the stem of a plant help to hold the plant up.

  2. Diffusion of Iodine and Starch through the Semi-Permeable Membrane of a Visking Tubing.

    Record results. Results Starting Colour Colour after 15 minutes Solution in Beaker. (iodine) YELLOW YELLOW Solution In Visking Tubing. (Starch). CLEAR PURPLE/BLACK Based on the observations the Iodine moved into the Visking Tubing turning the solution purple/black, whereas the Starch stayed in the same place.

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