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

Comparing The Water Potential Of Plants

Extracts from this document...

Introduction

Comparing The Water Potential Of Plants Aim The aim of this experiment is to compare the water potential of two different plant tissues, potato and sweet potato tubers, by measuring the gain or loss of water when samples of the tissue are placed in a range of concentrations of sucrose solutions. Background information Osmosis is the movement of water molecules from a region of their higher concentration to a region of their lower concentration through a semi permeably membrane. If the cell is surrounded by pure water (which has a water potential of zero), or by a solution that has a lower concentration and therefore a higher water potential, than that of the cell's contents water flows into the cell by osmosis and the cell would swell up (become turgid). The external solution is said to be hypotonic to the solution in the cell (hypo meaning lower than and applies to the solute concentration). If the reverse was to occur and the cell was surrounded by a solution whose concentration is higher and whose water potential is lower then that of the cell, the water would flow out of the cell into the solution. In this case the external solution would be known as hypertonic to the solution in the cell. ...read more.

Middle

To do this I placed a tile under the potato so that the surface was protected, and also took care while handling the knife so to protect myself and others. Once the potato samples were cut, I weighed them and then placed them into test tube with 20cm3 of different strength solutions. The potato was then left in the solution for approximately 2 hours 30 minutes. On taking the potato out of the solution I blotted it and reweighed it, to find out the new mass. Results On the next page can see two tables of results, these are from the experiment that I done and also a copy of the results supplied by Imogen Freeman. The reason that I also used Imogen's results was because I did not have time to conduct another experiment, so by using these results it is going to allow me to draw better conclusions, and also allow me to compare my results, and to look for consistencies or differences that might stand out. Please see attached graphs for experiment one and two, where I have compared the percentage change in mass against the different solution strengths. Sweet Potato Table of Results 1 Start mass (g) end mass (g) ...read more.

Conclusion

This is because when the cell is turgid, the vacuole has reached its maximum volume and no more water can enter the cell. When the cell is in a state of total plasmolysis then the vacuole has almost disappeared from the lack of water within the cell. If I was to do this experiment again, there are several improves and changes that I would make. The first thing I would do is to use smaller increases in solution strengths, at the point where the line on the graph appears to cross 0, this would allow me to find the exact point that water potential is equal to solute potential plus pressure potential. I would also repeat the experiment more times to enable me to find an average result and also spot a spurious result. Something else I could do, would be to leave both potato samples in the distilled water for longer to see how long it takes for them to become fully turgid. When doing this experiment you are never going to be able to all the samples of potato weighing and measuring exactly the same, and because of this the experiment is not going to be totally reliable. Nor are you going to be able to blot the potato sample's the same why every time you remove them from the solutions. Again this is going to cause inconsistencies in the results. ...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. Investigate the water potential of potato tissue and compare this with the water potential ...

    Preliminary work I carried out some preliminary experiments to test my method and also to ascertain the size of plant tissue I will be using. I also wanted to determine the length of time I would need to leave the experiment to ensure osmosis had fully taken place.

  2. 'Investigating how isotonic, hypertonic and hypotonic solutions affects the total mass of a potato ...

    Because there is more room for osmosis to occur. Vice versa. The size of the potato can vary. So will the amount of mass it can loose or gain. * The total volume of solution used must be exactly the same.

  1. Osmotic pressure

    I don't think there were many improvements to be made, only just to keep the experiment going on longer. At the end of it all we got good enough results to explain what changes there are through osmosis in different strengths of sugar solution.

  2. An Investigation to determine the Water potential of Potato cells.

    to begin with: 3.6, 1.25 and 1.07g respectively.codb dbr sedbdbw ordb dbk indb fodb db! I made up 20ml of each of my sucrose solutions and placed three different potato tissues into each of the test tubes. After 20 minutes I removed them and I used the scales to weigh

  1. Investigating the cellular water potential of potato cells.

    In the plasma membrane, the phospholipids are in two layers (hence the name phospholipid bilayer). The hydrophobic regions of the phospholipids line up together in the middle of the membrane, whilst the hydrophilic regions are on the outside of the membrane.

  2. The endeavour of this investigation is to ascertain if there is any effect of ...

    freely as the cell walls are permeable. However its movement is controlled by a number of factors which are given names; solute potential (), Pressure potential (+ Matrix potential =0 normally) () and water potential (). Solute potential (): this refers to the amount of substance dissolved in the cytoplasm.

  1. Use scientific knowledge and practical skills to determine the effect of a range of ...

    Also any clearly anomalous results will be ignored. 7:Temperature: The temperature may affect the reliability of the experiment for example at extreme temperatures the cells of the potato may die and at less extreme temperatures the experiment may be speeded up.

  2. Research Project - Comparing Antiseptics, Antibiotics and Disinfectants

    The wound should be cleaned first, and in most cases it should be covered with a bandage or other type of dressing to keep it clean and moist while it heals. However, some antiseptics, such as phenol, can damage the skin if the wound is covered after they are applied.

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