• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10

Determine the solute concentration of potato tissue

Extracts from this document...

Introduction

Preliminary Experiment Aim The aim of this experiment is to determine the solute concentration of potato tissue; i.e. To investigate at which point the sucrose concentration is the same as the solute concentration inside the potato (an equilibrium is reached) Introduction Osmosis is the movement of water molecules from an area of high concentration; (a weak solution), to an area of low concentration; (a strong solution), through a partially permeable membrane. My experiment will prove that the concentration inside the potato is lower than the concentration of the water molecules, outside the potato if using distilled water or very low concentrations of sucrose solution. Preliminary Method Cut two potato cylinders to the correct sizes e.g. 5cm in length, and dry them out using paper towels. It is important to dry out the potato cylinders because the excess water inside would have an effect on the results, and this would therefore create an unfair experiment. Then one must record their masses and lengths. Place them into the two different solutions; 1.0M of sucrose solution and distilled water, and leave them for fifteen minutes. One must leave the potato cylinders in the two different solutions for at least fifteen minutes because this is a minimum time, in which the starch particles will be able to diffuse into the surrounding liquid, if indeed that is the outcome. ...read more.

Middle

potato cylinder would increase in mass but the potato cylinder that was placed in 30 cm cubed of 1.0M of sucrose solution would be the only one to decrease in mass. The sucrose molecules in the sucrose solution are too big to be able to diffuse through the potatoes permeable membrane. In my main experiment I can predict that with a lower concentration of sucrose solution there will be a bigger increase in mass size. Results Mass: Sucrose (moles) Mass Before (grams) Mass After (grams) Mass change (grams) 0.0 2.663 2.801 0.138 0.1 2.914 2.760 -0.154 0.2 2.668 2.740 0.072 0.3 2.681 2.610 -0.071 0.4 2.854 2.753 -0.101 0.5 2.880 2.810 -0.070 0.6 3.035 2.823 -0.212 0.7 2.691 2.563 -0.128 1.0 2.843 2.723 0.138 Length: Sucrose (moles) Length Before (cm) Length After (cm) Length change (cm) 0.0 5.6 5.8 0.2 increase 0.1 5.6 5.7 0.1% increase 0.2 4.3 5.5 1.2% increase 0.3 4.7 4.3 0.4% decrease 0.4 4.4 4.5 0.1% increase 0.5 4.4 4.6 0.2% increase 0.6 4.5 4.7 0.2% increase 0.7 4.6 4.3 0.3% decrease 1.0 4.6 4.5 0.1% decrease Width: Sucrose (moles) Width Before (cm) Width After (cm) Width change (cm) 0.0 0.6 0.6 0 0.1 0.8 0.7 0.1% decrease 0.2 0.7 0.6 0.1% decrease 0.3 0.6 0.7 0.1% increase 0.4 0.8 0.7 0.1% decrease 0.5 0.8 0.6 0.2% decrease 0.6 0.7 0.7 0 0.7 0.8 0.8 0 1.0 0.8 0.7 0.1% decrease Percentage Changes in potato mass: 0.0M 6.29 ...read more.

Conclusion

However I only had one anomaly in my experiment and my conclusions drawn from my experiment were correct, meaning that my actions carried out during the experiment must have been done accurately and carefully. I trust my results because I know that I carried out the experiment by following all of the correct steps, and not just recording my results, but also developing my answers by thinking how and why I ended up with those answers. One method I could review would be when the potato cylinders were dried on the paper towel before they were placed into the solutions, because one cylinder may have been dried for longer which could have created a lower mass, which could have affected my overall results. Also cutting the potato cylinders to the correct lengths, widths and masses and having to measure them with a ruler, was very time consuming and not as precise as I would have liked. Therefore in the future I could use a more scientific way of carrying out this part of the experiment. If I ever carry out this experiment again, I will use a scientific piece of apparatus to record the temperature of the different solutions so that it is fair. Also some parts of the experiment were a bit limiting. For instance, I would have liked to have carried out the experiment a few more times using various types of potatoes, to see if the type of potato makes a difference to the conclusions which can be drawn from the experiment. ...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. Marked by a teacher

    An Experiment to determine Water Potential in Potato Tissue.

    4 star(s)

    I think this is caused by experimental errors. The technique of weight measuring might have caused many problems. I might not have settled the weight measurer completely before I used it. Also some water or solution might have been left on weight measurer from person before which could have affected the mass.

  2. Osmosis is defined as 'the movement of water molecules from an area of high ...

    5.86 5.51 -0.35 -7.20 3 5.80 5.39 -0.41 -8.54 AVERAGE 5.77 5.38 -0.39 -8.18 Analysis On the graph shown below, I have made the 'different solutions� as my independent variable, since it won�t be changing on any event. And I have made the 'percentage� as my dependent variable, because it doesn�t change in any particular order or a pattern.

  1. The Effect of Solute Concentration on the Rate of Osmosis.

    The water molecules in the solution and in the potatoes might also evaporate, a process I wouldn't be able to completely control. * Type of cell is vital in osmosis, because of the fact that the permeability of the membrane and the surface area of the membrane can be different

  2. To determine the water potential of potato tuber tissue

    loose the most mass, and the one in the solution with the least negative solute potential will loose the least mass. In this case, the solute potential of 0 actually relates to a mass gain. The measuring of mass in this experiment is an attempt to measure the gradient of water potential.

  1. Plan and carry out an experiment to determine the concentration of potato cell cytoplasm

    Time left for- The longer the time we leave the potatoes the longer the time we have for osmosis to occur. If we were to leave some specimens for a much longer time than the others, which would mean the potatoes left in their solution longest would have a greater rate of osmosis.

  2. Find out the effect of changing solute concentration on osmosis in potato tissue.

    leave the chips in time the amount of losing water or gaining water will eventually come to an end. The reason why the potato chip will stop losing water is because it needs to keep a little for the cells to live on.

  1. Discover the effect of water concentration on the mass of potato tissue, and investigate ...

    * Difference in concentrations - This will speed up the rate of osmosis because there will be more or less particles to move. * Quantity of each concentration - If there is more of a solution in one beaker than another the experiment will not be fair because there would

  2. Biology-2 QWC Practice Questions & Answers

    Additionally, temperature can impact the rate of diffusion; an increased temperature is likely to result in an increased diffusion. For example, comparing putting squash into water at room temperature and putting squash in boiled water; the squash in the boiled water would diffuse quicker.

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