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

Water Flow in Plant Tissue.

Extracts from this document...


Water Flow in Plant Tissue. Introduction and Background. Water Potential ? is the difference in intramolecular pressure exerted in a given specimen with reference to the intermolecular pressure exerted between molecules of pure free water at atmospheric pressure and the same temperature. The plant cell vacuole may be considered as a homogenous phase, separated by the tonoplast, cytoplasm and plasma membrane from the surrounding fluid. These may be considered as a single complex membrane, which is permeable only to water, that s for the purposes of this experiment. The cellulose wall which surrounds the cell is regarded as being completely permeable but of considerable strength and elasticity. Any pressure exerted by the cytoplasm on the vacuole is ignored in this experiment but is about 200 Kpa. The main pressure is exerted by the wall. In solutions of high water potential or in pure water the vacuole takes in water and expands. As a result the cytoplasm is pressed against the cell wall until the wall prevents any further expansion. Plasmolysed cell A plant cell can therefore come into equilibrium with pure water. At this point the cell has the same waster potential, as pure water i.e. ...read more.


1. A standard solution of sucrose is prepared using the formulae weight of sucrose as C11H22O11. 2. Dilutions are obtained so as to obtain a range of concentrations shown in the table below. 3. Sample of potato are freshly cut into rectangular pieces and measured for length, breath and width . As a working guide the aim was to use a length of five centimetres and a cross section of 1.4cm in other words a regular chip. A micrometer screw gauge was thought to be inappropriate here in view of the overall accuracy required in the experiment, a normal ruler was used measurements to the nearest 1mm. While working on other aspects of the experiment freshly cut chips are stored in distilled water to prevent aerial oxidation. 4. Two sample chips are placed in a constant volume of sucrose solution (10ml). 5. Thus two replicates are used for each sucrose concentration. 6. The samples are stored for 24 hours. The potato discs are removed dried between sheets of filter paper lightly and re-measured for their linear dimension. 7. A table of results will be drawn up to m record volumes before and after the experiment. ...read more.


Although the main driving force is often the transpiration rate driven by the sun. Seed germination may be slowed or prevented for example by a water deficit.. The seed surface contact is a significant factor. The seed coat is likely to be permeable to most common osmotica. Natural soil osmotica such as sodium chloride show some relationship with the nature of the habitat. Halophytes for example will germinate in relatively high sodium chloride concentrations that are inhibiting to glycophytes for example. Some desert plants are sensitive to rain. The Californian Filago californica will not germinate in moist cells, but any rainfall up to 20cm increases germination. Mass flow of solutes to the root surface may be controlled especially if elements not supplied by diffusion. For example Hoth and Norrish found the silicon content of Triticum vulgare (lemmas and glumes) to be strongly correlated with the total transported during growth. Appendix Table of Osmotic Potential in KPa of sucrose versus molarity mol dm -3 Molarity mol dm -3 Osmotic Potential Kpa 0.05 -130 0.10 -260 0.115 -410 0.20 -540 0.25 -680 0.30 -860 0.35 -970 0.40 -1120 0.45 -1280 0./50 -1450 0.55 -1620 0.60 -1800 0.65 -1980 0.70 -2180 0.75 -2370 0.80 -2580 0.85 -2790 0.90 -3000 0.95 -3250 1.0 -3500 ...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. Marked by a teacher

    An investigation into the effect of a germination inhibitor on the germination of seeds.

    3 star(s)

    The test provides a figure which can be interpreted to show whether this is the case. Below is a table of 6 people's results out of a class investigation. Day 1 Day 2 Day 3 Day 6 0* 10 25 50 75 100 0 10 25 50 75 100 0

  2. Marked by a teacher

    An Experiment to Determine the Water Potential (Ψ) of a Plant Tissue, using Discs ...

    3 star(s)

    Turgid and flaccid cells are a result of steep water concentration gradients between two materials. Apparatus: beetroot, 6 test tubes with bungs, distilled water, 1 molar sucrose solution, cork borer, blotting paper (paper towel), weighing scales, 10cm� pipette will pipette filler.

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

    I predict this because the concentrated solution will give more water potential than the pure water. Nearly all water leaving cylinder due to concentration gradient Solute concentration is more than the water, so water leaves Since this is the highest concentration I predict that the loss of mass will be around -----0.28g.

  2. Determine the Water Potential of Potato tissue.

    water potential (K Pa) 0.35 -970 Result 2 concentration of sucrose original weight of potato final weight of potato change in weight % change % change - 100 1 2.95 2.53 -0.42 85.76 -14.24 0.75 2.72 2.38 -0.34 90.49 -9.51 0.5 2.45 2.32 -0.13 94.69 -5.31 0.25 2.28 2.24 -0.04 98.25 -1.75 0 2.41 2.79 0.38 115.77 15.77 Concentration (M)

  1. Investigation into the relationship between the density of fresh water shrimps in fleet brook ...

    The male is about 25mm in length and the females slightly smaller. Their colour is usually lightish brown. Fresh water shrimps are largely scavengers, feeding on decaying organic matter, but they are also known to devour other smaller creatures. Gammarus pulex are found abundantly in freshwater habitats in the British Isles.

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

    Dilutions Molarity (mol dm^-3) Volume of 1M sucrose (cm^3) Volume of distilled water 0.00 0.0 10.0 0.25 2.5 7.5 0.50 5.0 5.0 0.75 7.5 2.5 1.00 10.0 0.0 Pilot Results Concentration (mol dm^-3) 0.00 0.25 0.50 0.75 1.00 Length before (cm) 7 7 7 7 7 Length after (cm)


    - To the length of the potato before and after the experiment. * Top pan balance-to take accurate mass of potato * Scalpel- To remove potato cover * Tile * Petri dish-To avoid water from evaporating * A roll of tissue -to dry the potato tissue RISK ASESSMENT * It

  2. Osmosis investigation. My prediction is that as the concentration of the solute increases, ...

    The surface area of potato- this can affect SA:V ratio in osmosis reducing reliability of results. The Main Plan: Equipment: 1. Test tube rack- there isn't a better alternative for the same purpose. My only principle was that it is easier to keep track of the potatoes when they are in a rack.

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