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

Investigating osmosis in plant tissue.

Extracts from this document...

Introduction

Investigating osmosis in plant tissue Introduction Osmosis is the movement of water particles along a concentration gradient, from a high concentration to a low concentration through a selectively permeable membrane. Osmosis can happen anywhere where there is a selectively permeable membrane and water, however can only move along the concentration gradient. For example if a red blood cell were to be placed in water, then water would travel through diffusion into the red blood cell as the water concentration inside a red blood cell is quite low. However animal cells only have a cell membrane, so the blood cell would fill and fill, and keep on filling until the membrane could hold it no longer and it would burst. Whereas with a plant cell, it has a cell wall, so instead of bursting, a plant cell will merely become turgid, or swollen and hard. This is where the pressure inside the plant cell increases and increases until no more water can enter and the cell is turgid. This is the pressure is called turgid pressure and keeps plants standing up, and why plants wilt when not enough water is consumed by the plant, this is called flaccid. ...read more.

Middle

could affect osmosis, and we know that the volume, size and surface area of each cylinder is the same, and as they are all from the same potato, the only variable that we are altering is the concentration of the solution. When conducting the experiment we need to remember to keep it a fair test, whilst doing so we need to consider these things: -Keep the potato samples the same length (2cm). This is because if one potato sample is 1cm long and one is 3cm long then the 3cm long sample will have a larger surface area and osmosis will occur much faster -Average: To make the experiment as accurate as possible an average will be taken out of 3 results for each solution taken. This is so that we can determine which results are accurate and which are anomalous. Trial experiment Molarity Mass at 0mins 15mins 30mins 45mins 60mins %Mass change 0 4.83 5.25 4.97 5.02 5.01 3.72 0 4.68 5.16 5.33 5.42 5.41 15.6 0.6 4.21 4.73 4.46 4.36 4.27 1.42 0.6 4.69 5.06 4.63 4.55 4.41 -5.97 1 5.04 4.01 4.2 4.03 3.9 -22.61 1 4.57 4.41 3.8 4.36 4.36 -4.6 In the trial experiment, we discovered that our original experiment plan wasn't quite as good as it could be, and this was true for many reasons. ...read more.

Conclusion

The experiment however apart from certain knocking over incidents was fairly reliable, as long as you considered all the factors that could affect the test and all the precautions you needed to take to make sure it was a fair test the experiment was very reliable. There were however a few limitations, mostly to do with equipment; there weren't nearly enough weighing machines, ergo mass pile ups were cause queueing to use them and times were occasionally missed by some groups, what would have made this much easier would have been to have a mass cooperation from each and every group as to which times and when they could use the weighing machines. There could be a few improvements made for this experiment, what we could have done is have lots of different groups doing one molarity each however lots of times, this would have created much more accurate results and eliminated anomalous results. Another thing that I would like to do is alter all the factors, e.g. size, surface area, temperature and also try it with not only different vegetables but fruit as well. I could also then vary the solution, e.g. instead of sucrose use another liquid substance present in fruit and vegetables. Apart from this I feel the experiment was highly successful and thoroughly enjoyed. ...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 Exchange, Transport & Reproduction section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Here's what a teacher thought of this essay

3 star(s)

This is a well structured report that covers most of the necessary aspects of this investigation:
1. The use of subheadings is good but there are several sections with running commentaries.
2. Researched information needs to be referenced.
3. An analysis of the results needs to be carried out.
4. The evaluation shows some understanding of principles but be careful with claims made about accuracy.
***

Marked by teacher Luke Smithen 23/07/2013

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 Exchange, Transport & Reproduction essays

  1. Marked by a teacher

    Mr Chips: Investigation to find an isotonic solution for potatoes

    4 star(s)

    so they should be kept away in a safe place * Be careful of glassware Results Table 3 Recorded weight of potato, before and after experiment Concentration NaCl solution % Initial Mass (g) Final Mass (g) 0.0 1 4.02 4.12 2 4.21 4.44 3 4.11 4.37 0.5 1 4.23 4.20

  2. Marked by a teacher

    An investigation on the effect of temperature on beetroot membrane structure.

    4 star(s)

    many proteins are denatures by temperature at around 40-500c, but some are still active at 70-800c and few even withstand being boiled..." (5) Systematic errors: According to my results at 60-700c the absorbance of beetroot pigment start to increases dramatically and this is due to proteins denaturing.

  1. Marked by a teacher

    An Investigation into the Water Potential Of Root Vegetables.

    4 star(s)

    % Sucrose solution. Average change in length (cm) Average change in mass (g) 20% -0.02 -0.42 10% +0.07 +0.35 5% +0.07 +0.14 2.5% +0.08 +0.22 0% +0.20 +0.30 Diagram of Apparatus. Fair Testing. All the potato pieces and swede pieces will be in the solutions for the same amount of time so that it's a fair test.

  2. Marked by a teacher

    The Effect Of Temperature On The Permeability Of The Cell Membrane

    3 star(s)

    This is used to pick the beetroot up from the beetroot solution, Why? I must be careful not to squeeze the beetroot too much or this could lead to damaging the beetroot hence damaging the cell membrane of the beetroot.

  1. Osmosis in Living Tissue.

    and record * Put the skewed chunks into the different solutions, noting down which test tube had which solution in * Leave the test tubes in a cold place for 3 days * Take the test tubes out and note down the length of each individual chunk * Dab off

  2. Osmosis in Potato cells

    Method of drying the potato. Final mass of the potato chip. Time in which each potato chip is left in the solution. Volume of the solution. Original length and original mass of each potato chip. Temperature of the room and solution for each potato chip.

  1. An investigation to see whether the concentration of Sucrose effects the amount of Carbon ...

    This is because there will still be the same amount of sugar for the yeast to respire at full potential but there will also be excess, that the yeast won't be able to respire on in a certain time (because the amount of yeast is also a limiting factor.)

  2. The Effect of Different Substrates on the Rate of Respiration on Yeast (Saccharomyces cerevisiae).

    Sucrose is hydrolysed` (inverted) into glucose and fructose by invertase present on the cell surface of regular bakers' yeast. Lactose (milk sugar) is not fermented by regular bakers' yeast. This is the only variable that is being manipulated Conclusions and Predictions Having studied the theory on yeast, the substrates, and

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