• 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
  11. 11
    11
  12. 12
    12

The purpose of my investigation is to find out the concentration of the cell sap in potato cells.

Extracts from this document...

Introduction

Biology Science Investigation The purpose of my investigation is to find out the concentration of the cell sap in potato cells. To do this I will need to place potato pieces in different concentrations of sucrose. Water will pass in and out of the cell through osmosis meaning that the potatoes will lose or gain mass and there will be one that has the same mass at the beginning and end of the experiment. The solution that the potato is in will equal the concentration of the cell sap. Before I can do this experiment I will need to find out what is involved in the process of osmosis and what causes it to stop. According to "Encarta" osmosis, is when water diffuses from a solution of low concentration to a solution of high concentration through a semi-permeable membrane. Diffusion is the movement of molecules from a region in which they are highly concentrated to a region in which they are less concentrated. When a substance like sugar dissolves in water, the sugar molecules attract some of the water molecules and stop the from moving freely. This reduces the concentration of water molecules. In my diagram below you can see that the half of the water molecules on the right side have been attached to the sugar molecules. There are more free water molecules on the left of the membrane then on the right, so the water will diffuse quicker from left to right across the membrane than from right to left. ...read more.

Middle

This is because the cell concentration and the solution concentration is exactly the same and osmosis has not occurred. The formula to figure out the percentage increase is The potato will be cored giving it the same width and dimensions and then stored in water. Then 6 pieces of the potato will then by dried and cut in to three pieces of 1cm in length, weighed then the pieces will be placed in boiling tubes containing solutions of sucrose, with the concentrations varying from 0%(pure water) - 10%. Three pieces of potato will be placed in each and the volumes of the solution will 5cm. The weight will be given to two decimal places and The average of the three potato pieces on each boiling tube will be taken. The test tubes would usually be left for 24hours and then taken out of the solutions, dried and weighed again and the average taken. Results 1st Experiment Mass before Mass after Sucrose Concentration (%) Mass (g) Ave Mass (g) Mass (g) Ave Mass (g) 1st piece 2nd piece 3rd piece 1st piece 2nd piece 3rd piece 0 0.99 1.03 1.06 1.03 0.79 0.77 0.77 0.78 2 1.07 1.00 1.10 1.06 0.72 0.80 0.86 0.79 4 1.01 1.12 0.99 1.04 0.80 0.71 0.65 0.72 6 1.10 1.13 0.82 1.02 0.68 0.79 0.88 0.78 8 1.07 1.07 0.99 1.04 0.88 0.74 0.79 0.80 10 1.06 1.01 0.91 0.99 0.86 0.95 1.00 0.94 2nd Experiment Mass before Mass after Sucrose Concentration (%) ...read more.

Conclusion

Or perhaps the potato chip was not cut accurately, or that part of the potatoes, cells did not loose/gain mass well, this may have been because the potatoes were put in water before the experiment and osmosis may have already occurred causing water to diffuse out of all potato cells when I started the experiment. My results did vary a lot for the same concentration. The fact that a certain part of the potato may not be the same as another was shown as the chips all of the same length was not the same weight. I could extend my enquiry by testing the percentage change in mass with sugar solution using a different substance. By this I mean using a different vegetable. Then I could find out whether osmosis occurs with the same patterns and trends with any vegetable. Such as carrots. The carrot would be cut into 18 pieces with the same length and width. The pieces will then be weighed and the average taken and three pieces will be placed in boiling tubes each containing different sugar concentrations ranging from 0% to 10%. The test tubes will be left for 24 hours and then they would be taken out of the solution weighed again and the average taken. The percentage increase would be found out using the formula. I could also find out if the same patterns and trends occur in osmosis with different solutions such as salt. I would follow the same method as I mentioned above except I will use salt solution instead of sugar ...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. Osmosis. An experiment to find the concentrations of salt solution which is the ...

    This proved that the salt solution was more dilute than the concentration of cell sap in the potato. Thus by osmosis, the water molecules diffused across the semi permeable membrane, then entered the core, increasing the potato's mass, and making it turgid.

  2. Find the concentration of Potato Cell Sap.

    My Prediction is: * The stronger the sucrose solution is, the smaller the potato strips will be finally. * The strips in the very weak solutions may grow a bit, with water growing the most. * The concentration of the cell sap will be somewhere between the concentrations of 0.2 and 0.3.

  1. Investigating the cellular water potential of potato cells.

    This will also allow for any anomalies within my experiments and so make my results more reliable. Apart from the concentrations of the sucrose solutions that I will be using, there are many other variables that I must consider within this experiment, which could affect the results that I obtain.

  2. An Investigation to determine the Water potential of Potato cells.

    Distilled watercoag agr seagagw orag agk inag foag ag! Would produce more accurate results than using tap water, which contains minerals, salts, fluoride, sulphur and chlorine. Calcium and magnesium in the water would make the water hard. These impurities contaminate the water and lower the ?. 3ETRvaxyO from 3ETRvaxyO coursewrok 3ETRvaxyO work 3ETRvaxyO info 3ETRvaxyO 1.0 mol dm -3

  1. To find out the concentration of cell sap

    Using the same type of potato as different potatoes may have different water potential. 6. Running the experiment for the same amount of time for all potatoes. This is because time the time the experiment runs for can effect the mass gain or loss.

  2. To determine the concentration of the cell sap in potato storage tissue. By using ...

    Find difference between start and finish weight for each piece of potato in each solution. Fair Test Many factors could affect the fairness of the experiment. For example temperature may affect the rate of Osmosis. Here's what I will do to make it a fair test: * Each potato

  1. What is the concentration of the cell sap in the vacuoles of potato cells?

    The mass of the sausage filled with one mole of sucrose was 19.16 grams and after it had been left for three days its mass was 23.02 grams. The mass of the sausage filled with water went from 19.1 grams at the start of the experiment to 6.36 grams at the end.

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

    Using more types of molar sucrose solutions would have helped us obtain better results, and more accurate results, so that we can make sure the results are totally correct. Experimenting with one set for a longer period of time, for each set, would lead us to better results, because the

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