• 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

Investigate the effect of varying concentration of sucrose in a solution on a potato cylinder of a given size.

Extracts from this document...

Introduction

An experiment to calculate the rate of osmosis in potatoes Skill Area P Planning Experimental Procedures Aim: To investigate the effect of varying concentration of sucrose in a solution on a potato cylinder of a given size Hypothesis: Osmosis is defined as the net movement of water molecules from a region of high water concentration, to a region of low water concentration, osmosis takes place across a partially permeable membrane, which only allows smaller molecules like water pass through it, and doesn't allow bigger molecules like sucrose to pass through. In this experiment the partially permeable membrane is the cell membrane of the potato cylinders. The water molecules will continue to diffuse until both sides of the partially permeable membrane have the same amount of water molecules and are equal- i.e. that there is the same amount of water molecules in the potato cylinder, than in the solution surrounding it. I predict that the lower the concentration of sucrose solution in the test tube the larger the mass of the potato cylinder will be. This is because the water molecules pass from a high concentration, i.e. in the water itself, to a low concentration, as there are more water molecules in the pure water solution than there is in the respective potato cylinder, due to osmosis the molecules will pass through into the potato, causing its mass to increase. ...read more.

Middle

- Stop watch Method: Prepare the 40mm potato cylinders with corer, ruler and scalpel, prepare the solutions (using syringe), blot (using tissue paper) the cylinders (roll for 5 seconds forward), weigh them, and record results. Using stopwatch, put respective cylinders in respective solutions (using china graph pencil to make sure we don't got confused, and time 25 minutes. After blot the cylinders, and weigh. Record results. Repeat method again for second set of results. Variables I am going to control To create a fair test certain aspects of the experiment will have to be kept the same whilst one key variable is changed. The key variable in this experiment is the concentration of the sucrose solution. If any of the non-variables below are not kept constant then it may influence my results, which would make this experiment an unfair test. For example if one of the potato cylinders was 50mm instead of 40mm, this could greatly influence my results, as then there is an extra 10mm of surface area for osmosis to occur. Below are the aspects I am going to control, as they could influence the experiment and make it an unfair test: - Temperature: by doing all tests in one room at a constant room temperature, as eat may cause a change in the kinetic energy of the molecules, thus speeding up the process of osmosis, and altering the amount of water molecules which may pass through the membrane, thus altering the mass of the potato cylinder. ...read more.

Conclusion

not to 0.00g but to 0.0000g. There were not any out of the ordinary results, but some were not as close to the line as others i.e. (2, -11.32), contamination or inaccuracies may have caused this. Also I felt that there must be another method of blotting, as I feel that I may have dried some more thoroughly than others, also next time I would have wiped the scales and my hands each time I came in contact with the cylinders, and perhaps this would have solved the anomalies on my graph. If the experiment was repeated, I could find another way to dry the potatoes that would ensure that all were dried in the same way for the same time. Also I had to use 3 different potatoes on different days, which may have affected the results as each potato has a different water concentration, perhaps I could conduct all the experiments using the same potato, or maybe be use a mention that measured water concentration- this would make my results far more accurate. However with all this said I think that the experiment was successful and I was pleased with the complete comparison of my results with my initial prediction. For further experiments I could measure how the varying concentrations of a sucrose solution affects the rate of osmosis on different vegetables; and see whether they reflect the results I obtained in this experiment. Anna Iqbal 10G 1/9 Biology Mrs Trustler ...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

    How does the concentration of a sucrose solution affect the rate of Osmosis in ...

    5 star(s)

    Set 2 of experiments is an anomaly as far as the isotonic points go, as it had an estimated concentration of 12% sucrose, even though the same potatoes were used. This anomalous reading could be down to things such as the potatoes being cut slightly different sizes, or that experiment accidentally being left in a slightly warmer environment.

  2. Marked by a teacher

    Investigating the effect of Sucrose Concentration on the Rate of Osmosis in Potato Chips.

    5 star(s)

    I obtained one anomalous result that didn't conform to the curve of best fit which I drew. It claimed that when the concentration of sucrose solution was 0.6mol/litre, the average percentage change in mass was -8.10%. This result might have been caused due to the oxidation of some potato chips in the air.

  1. Marked by a teacher

    An experiment to investigate how the effect of varying concentrations of salt solutions play ...

    4 star(s)

    This membrane in cells is generally the same size. However, plant cells have the presence of the cell wall, which contributes to the thickness of the cell membrane. Therefore, since the membrane is thicker, the rate of diffusion is greater as the water molecules must move over a greater distance.

  2. Marked by a teacher

    Investigating the effect of sucrose concentration on osmosis in potato cells

    4 star(s)

    o Measuring cylinders: to measure out the correct volumes of sucrose solution and water so that I can achieve the desired concentrations; o A Graduated Pipette: to ensure that the concentrations are completely accurate; o 6 x 150ml beakers: to conduct the experiments in; o A top-pan balance: to measure the mass of the potatoes before and after osmosis.

  1. Marked by a teacher

    To investigate how varying the concentration of sucrose solutions affects the rate of osmosis ...

    3 star(s)

    Observing plant cells in concentrated sugar solutions under a microscope, we can see that the contents of the cells have shrunk and pulled away from the cell wall causing the cells to become plasmolysed. This is so because water continues to leave the cell, the cell membrane gradually draws away

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

    I will cut 7 (multiplied by the number of repeats (3)) chips into equal lengths of 3cm. After I weigh them and record these results, I will place them into pre-labeled test tubes of which are already containing 25ml of the relevant solution.

  1. Experiment to find the concentration of sucrose solution where there is no change in ...

    For the next experiment I decided to use concentrations of sucrose between 0.0M and 0.5M because my preliminary results showed that the point where the molecules pass constantly but equally through the selectively permeable membrane was between these two points because 0.0M increased in mass showing that the solution had

  2. Osmosis, Aim: To investigate the effect of varying concentration of a certain sugar solution ...

    "X I am also going to use the same balance to weigh my potato chips. This is because the measurements may slightly vary between scales. TABLE SHOWING THE DIFFERENT VARIABLES THAT WILL BE CONSIDERED DURING THE EXPERIMENT Variables Non-Variables Solution concentration Surface area Solution volume Duration of experiment Temperature Solution

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