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

Determining the water Potential of Cereliac

Extracts from this document...

Introduction

Determining the water Potential of Cereliac The Celeriac Plant produces a beetroot like stem tuber. This stem tuber is called Celeriac. Water leaves or enters cell by osmosis. This depends on the water potential inside and outside the cell. Generally water travels from a region of higher water potential to a region of lower water potential. However other factors like pressure can also have an influence on osmosis. 'Pure water has the highest possible water potential.'1 To determine the water potential of celeriac we must carry out some experiments using a range of solutions with different concentrations and viewing how the cereliac samples change in the solutions by using a microscope to see how many have then plasmolysed. In the class room an experiment was carried out where the incipient point of some onion cells was found in a very similar way as described above. There is a graph present showing the results of the experiment on a separate page. As shown on the graph it takes a sucrose solution of 0.5867 mol/dm� to reach the incipient plasmolysis point of the white onion. The white onion therefore has a water potential of -1.667MPa. ...read more.

Middle

The microscope must be focused before the experiment is carried out and use of a medium or high power magnification is recommended 4. Count the number of cells in the field and count the number that has plasmolysed. Calculate the percentage plasmolysis. 5. Plot a graph of the percentage of cells that have plasmolysed against the molarities of the sucrose. 6. From the graph read of the molarity of sucrose that responds to 50% plasmolysis. 7. Make the solution that would create 50% plasmolysis and repeat steps 1 to 4 to ensure that the correct value has been attained. A similar experiment was done before in the classroom but the water potential of some onion cells was found instead. Some of the problems were clearly identifying if cells were plasmolysed or not and also the difficulty of obtaining a one cell thick cell sample to view under a microscope. To obtain small sheets one cell thick of the plant specimen it is advised that one uses an instrument called a microtome. However using this piece of apparatus can be quite tricky. First there has to be enough living tissue at the edge of the instrument to cut. ...read more.

Conclusion

White Tile Provides hard and non reactive surface onto which the celeriac can be cut. A pair of rubber gloves Avoids contact with skin when holding the celeriac. This reduces the possibility that grease from an ones hands can come in contact with the plant specimen. Grease is non-polar, whereas water is polar. The grease could thus hinder osmosis. Scalpel To cut the celeriac peels into suitable sizes. Slides and Cover slip To place the Celeriac on so it can be viewed. Microscope To view cells in detail 18 Small Beakers or Conical flasks These will be used to emerge the plant sections. Their size should be around 100 ml. 2 Pipette Fillers To safely fill the pipettes Calibration table- to find the water potential once the concentration of the sucrose that gives the incipient plasmolysis point is found Concentration/ moldm3 Water Potential /MPa 0.10 -0.26 0.15 -0.41 0.20 -0.54 0.25 -0.68 0.30 -0.82 0.35 -0.97 0.40 -1.12 0.45 -1.28 0.50 -1.45 0.55 -1.62 0.60 -1.80 0.65 -1.98 0.70 -2.12 0.75 -2.37 0.80 -2.58 0.85 -2.79 0.90 -3.01 0.95 -3.25 1.00 -3.51 All water potential values given of thus given molar concentrations of sucrose at 20� Celsius. It is thus important to work in this temperature to ensure accurate results are obtained. 1 Biology One, Page 56 2 Biology One, Page 58 ...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 Green Plants as Organisms 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 Green Plants as Organisms essays

  1. Determine the water potential of potato tuber cell with the varying affect of solute ...

    Since water always (in osmosis) moves down the concentration gradient, it means that more water will move out of the cell since there is less water in the solution (surrounding medium). More water leaves, only a little is entering now This is a high concentration so the water loss will

  2. Investigate and find the water potential of baking potatoes and sweet potatoes in (N/mm2) ...

    the outcome of the experiment because the amount of impurities in the potato will govern its water potential. Potatoes have 76g of water for every 100 grams, whereas sweet potatoes only have 70g of water every 100g. This already shows that baking potatoes have more water and therefore a less negative water potential than the drier sweet potatoes.

  1. TO FIND THE WATER POTENTIAL OF PLANT TISSUE CELLS.

    Average Percentage change in mass(%) Distilled water 1. 2.36 2. 2.37 3. 2.37 1. 2.58 2. 2.74 3. 2.72 1. 0.22 2. 0.3 3. 0.35 0.29 12.25 0.1 1. 2.40 2. 2.42 3. 2.28 1. 2.51 2. 2.58 3. 2.48 1. 0.11 2. 0.16 3. 0.2 0.15 6 0.25 1. 2.41 2. 2.42 3. 2.46 1. 2.42 2.

  2. Investigation into the water potential of celeriac.

    This is due to the celeriac cells own water potential being greater than the surrounding solution's water potential. The sucrose solution had increased so much that the solute concentration in the solution would be higher than that in the cells.

  1. Determining the water potential of potato tuber cells.

    Using a table that expresses the relationship between molarity and water potential (Roberts 1991) and referring to other scientific evidence (W D Phillips and T J Chilton) I know that the if there is no change in weight in my potato tuber cell samples then the water potential in both the regions have reached equilibrium.

  2. The aim of this experiment is to determine the water potential of celeriac cells ...

    An animal cell with no cell wall to hold it in will explode if it takes in too much water. The turgor pressure against the cell wall forms the "pressure potential" (Q[p]), a positive value. (The higher the pressure inside the cell compared to the pressure outside the cell, the more likely water is to leave the cell, i.e.

  1. Investigation to find the water potential of a plant cell.

    Because the solute molecules are too big to pass the partially permeable membrane, the water molecules move via osmosis. Because solution B has a higher solute to water ratio than solution A, solution B has a lower water potential. And because water moves down its water potential gradient, from a

  2. Investigate the water potential of beetroot tissue using experiments and your own knowledge.

    The volume of liquid in the tube of sugar solution will eventually rise until the flow of water from the tube of sugar solution, under the influence of hydrostatic pressure, just equals the flow of water into the tube. Thereafter, no further rise in volume will occur.

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