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

the movement ofwater molecules only across a membrane. The water molecules willcontinue to diffuse across the membrane until equilibrium betweenconcentrations is established.

Extracts from this document...


the movement of water molecules only across a membrane. The water molecules will continue to diffuse across the membrane until equilibrium between concentrations is established. Osmosis takes place in both plant cells and animal cells. Animal cells do burst in pure water. The cytoplasm inside the cell is quite a concentrated solution of proteins and other large substances. Therefore osmosis will take place between the cell and the surrounding fluids via the partially permeable membrane (the cell membrane). The cell will soon burst because of the swelling from the increase in water. Plant cells do not burst in pure water, though, because they have a cell wall that is fully permeable so osmosis does not take place across it. It is bypassed and osmosis takes place between the cell membrane in the same way as an animal cell, but with the resistance of the strong cellulose of the cell wall to keep the cell from bursting. When a plant cell is pushing out against the cell wall (like an inflated football) ...read more.


With regard to the osmosis, it will be taking place across cell membranes in the potato. The cells in the potato will be similar to the plant cells explained previously in terms of how osmosis occurs. Therefore I predict that water will diffuse into the potato if it is put into pure water. Also I expect water to diffuse out of the potato if it is put into a very concentrated sucrose solution. This is because there must be a considerable amount of water in the potato cells already seeing as a potato is a root vegetable and absorbs water into the ground. The sucrose concentration of the potato will be found when the potato is put into a concentration of solution in which no osmosis or diffusion of water takes place. From my own general knowledge I know that the water content of potatoes is approximately 70%. This is a notorious quantity of water found in nature e.g. the composition of humans is 70% water, the composition of the Earth is 70% water etc. ...read more.


To make the concentrations I used the following proportions: 1.0M Sucrose Solution (ml) Water (ml) Resulting Concentration 1 10 40 0.20 2 12 38 0.24 3 14 36 0.28 4 16 34 0.32 5 18 32 0.36 6 20 30 0.40 I made the solutions by using pipettes to measure the sucrose solution in one beaker and the water in a second beaker, then mixing both in a third beaker with a stirrer. With another pipette I put 10ml of each concentration into two test tubes so that there were two tubes with 0.2M, two tubes with 0.24M etc. I measured the mass of the potato cylinders and recorded the values, before putting the cylinders into the solutions, one cylinder in each test tube. I put labels on each tube to show which tube contained which concentration so that there was no error in mixing up the results. After leaving the potatoes for 24 hours (probably sufficient time for osmosis to take place) I drained away the solutions from the tubes, took out the potato cylinders and reweighed them, recording the new values next to the previous ones. ...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. Osmosis is defined as 'the movement of water molecules from an area of high ...

    To make the amount of solution placed in the test tube as accurate as possible a syringe will be used to measure out the exact amount needed. 5: Contamination: As each test tube is filled up with the different molar solutions the syringe which would measure the amount of solution

  2. Osmosis is the passage of water molecules from a weaker solution into a stronger ...

    tissue paper (to remove excess water on the exterior of the potato chip that may effect the weight and therefore the results) and weighed and measured once more. These measurements of length and mass will also be recorded in the table to be analysed. Fair Test: Many variables effect osmosis.

  1. Looking at how concentration affects the movement of water particles through a partially permeable ...

    When a dynamic equilibrium is established and both solutions are of equal concentration they are said to be isotonic. The above terms should only be applied to animal cells. The osmotic relationship of plant cells should be described in terms of water potential.

  2. Osmosis is diffusion of fluid through a partition into another fluid, movement of water ...

    Dilute Cell has Cell Dilute gone bigger Sugar Sugar (Expanded) Solution Solution When a plant cell is placed into a concentrated sugar solution it also has affect on the plant cell because it makes the cell go smaller in size and it goes lighter in weight because the water has

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