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

An Investigation to Find the Concentration of a Potato Cell Sap

Extracts from this document...

Introduction

An Investigation to Find the Concentration of a Potato Cell Sap Definition Osmosis is the movement of water from a weaker/more dilute solution, to a stronger/more concentrated solution through a selectively permiable membrane. We desplayed what will happen using a model cell experiment in which we subsituted visking tubing bags for cells. We placed glucose in one cell and water in the other. We then placed the cell filled with glucose in a test tube filled with water and placed the cell filled with water in a test tube filled with glucose. The results of this experiment showed that the cell filled with water lost weight and the cell filled with glucose gained weight therefore prooving the definition. Prediction I predict from a preliminary experiment that the concentration of the cell sap is 0.3 Molar. In the preliminary experiment we prepared three concentrationss: 0 Molar, 0.5 Molar and 1 Molar, and three potato chips all the same length. ...read more.

Middle

To be accurate, we will record the mass change in percentage and to calculate this we will use the equation: %change = (change in mass/original mass) x 100 Apparatus Method We are going to use potatoes to conduct our experiment because they are still living and have cell membranes. We will use 0.2, 0.3, 0.4, 0.5 and 0.6 Molar solutions of distilled water and glucose. We will measure the different Molar concentrations out by using a pippette, a measuring tube and a beaker. We will use the distilled water to make sure that it is a fair test and that the only thing dissolved in the water is glucose. We will cut five potato chips to excatly the same length, measure and weigh them, and drop them into the solution at exactly the same time. After 30 minutes we will take out the chips, dry any excess liquid off them, and reweigh and measure them. Analysation and Conclusion First Experiment Results Mass/g Length/mm Solution/M Original New Change %Change Original New Change Texture 0.2 3.27 3.35 0.08 ...read more.

Conclusion

But, there is a pattern in the opposite direction going in an inversely proportional way which means that as the concentration of the solution increases, the percentage change in mass decreases. My graph shows that there was an overall decrease in mass during the experiment. Evaluation My results were quite accurate but it was hard because the Molar solutions were hard to measure out as they were so tiny also we did the two experiments on different days so the teperature in the lab could have changed which would mean that one of them would work faster than the other. We didn't have any anomalous results which was good. Next time I did this experiment, I would change the length of time the potato chips were in the solution - I would work quicker at the beginning of the lesson to try and give them about 45 minutes in the solution. The results we got were enough to support a firm conclusion because we did a wide range and then we did a very narrow range which was more accurate. ?? ?? ?? ?? Claire Auchivole 10T ...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

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

    Osmosis. Aim: To find the molarity of potato tubers cell sap. BIOLOGICAL ...

    4 star(s)

    its contents, osmosis wouldn't be taking place and there would be no net movement of water as the number of free molecules are same on either side of the semi-permeable membrane. Factors affecting Rate of Osmosis The rate of osmosis is often varied due to different factors.

  2. Peer reviewed

    "An investigation into the Respiration of Carbohydrate Substrates by Yeast."

    5 star(s)

    We used a computer to carry out the t test as follows: 1. Record your results in Excel. 2. Go to 'Tools' and select 'Data analysis'. 3. Select't test: two sample assuming equal variances.' 4. Click on the box that says 'variable one' and highlight the first set of data you want to compare.

  1. Investigation on Osmosis using a potato.

    Amount of Sucrose(ml) 1 Molar Amount of Water(ml) Percentage Change (%) 1.39 1.92 0 30 38.1294964% 1.37 1.82 3 27 32.84671533% 1.42 1.75 6 24 23.23943662% 1.31 1.58 9 21 20.61068702% 1.36 1.58 12 18 16.17647059% 1.44 1.52 15 15 5.555555556% 1.33 1.35 18 12 1.503759398% 1.37 1.32 21 9 -3.649635036% 1.35 1.28 24 6 -5.185185185% 1.38 1.25

  2. Design an experiment to investigate the effect of temperature on the movement of a ...

    This is why it stays in the vacuole and doesn't leak into the rest of the cell. The pigment can also not escape through the tonoplast because it is water-soluble; therefore it is polar and cannot get through the fatty acid tails of the phospholipids, because they are non-polar.

  1. permeability of beetroot membranes

    We then placed a different group of potato discs into different test tubes. Each of these test tubes contained 15 millilitres of glucose solution of different concentrations. These concentrations increased by 0.25 moles/dm3 each time, starting at 0.00 M (distilled water).

  2. Investigating the concentration of cell sap in potatoes

    Each group had its own weight range. The first group of potato, weighed between 0.92g and 0.98g. The second group weighed between 1.19g and 1.32g. The third group weighed 1.45g and 1.49g. We poured 5ml of different concentrations of water and sugar over the potato. These concentrations were: * Distilled Water * 0.05 Molar of sugar *

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