• 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
  13. 13
    13

The aim of this experiment is to determine which are sweeter potatoes or apples. We will determine this through the principles of osmosis.

Extracts from this document...

Introduction

Aim The aim of this experiment is to determine which are sweeter potatoes or apples. We will determine this through the principles of osmosis. Sucrose Solutions A set of six solutions will be used in this experiment. The solutions will be ready formulated by the technicians. Measuring Cylinder To accurately measure liquids, a measuring cylinder (ml graduations) will be used. Digital measuring scale with grams Before and after the experiment potato and apple pieces will be weighed to measure any change in mass. Stick rule with millimetres A stick rule will be used to measure any change in length of the potato or apple pieces from before the experiment. Beaker This will be used to pour excess or used sucrose into during the experiment. Test tubes Twelve test tubes, each will be used to containing potato or apple pieces in sucrose solution. Tweezers To handle the potato or apple pieces and prevent contamination. We would need to use tweezers preferably one for each. Filter paper In order to absorb the excess fluid filter paper will be used. This would prevent including water mass in weighing potato and apple pieces. Cutting board A cutting board will be used to protect tables and to provide a safe and stable cutting surface. Blade To cut off excess pieces of apple or potato. Test tube holder We will use a test tube holder to store test tubes before and during the experiment. Corer To cut out large uniform pieces of apple or potatoes a corer will be used. Marker pen In order to correctly identify test tubes and their contents, they will be labelled correctly with marker pens or glass crayons. Apparatus Hypothesis My hypothesis is that the greatest increase in mass and length will be seen at the lowest concentration (0 M). This is because it is water and so water will move into the cells. ...read more.

Middle

M 20 20 20 20 20 20 17 18 0.8 M 20 20 24 20 20 20 18 19 1.0 M 20 20 19 18 20 20 20 17 Mass of Apple Pieces (g) Mass of Potato Pieces (g) Concentration of Sucrose Solution (Molar) Before Treatment After Treatment Before Treatment After Treatment Bottom piece Top piece Bottom piece Top piece Bottom piece Top piece Bottom piece Top piece 0.0 M 1.3 1.3 1.4 1.2 1.6 1.7 1.9 1.9 0.2 M 1.5 1.2 1.6 1.4 1.6 1.8 1.6 1.8 0.4 M 1.4 1.5 1.5 1.6 1.7 1.8 1.2 1.3 0.6 M 1.5 1.3 1.4 1.3 1.6 1.6 0.9 1.0 0.8 M 1.5 1.3 1.4 1.3 1.6 1.9 0.7 0.9 1.0 M 1.5 1.4 1.3 1.4 1.9 1.7 0.8 0.8 Length of Apple Pieces (mm) Length of Potato Pieces (mm) Concentration of Sucrose Solution (Molar) Before Treatment After Treatment Difference (�mm) Before Treatment After Treatment Difference (�mm) Bottom piece Top piece Bottom piece Top piece Bottom piece Top piece Bottom piece Top piece Bottom piece Top piece Bottom piece Top piece 0.0 M 20 20 21 20 +1 0 20 20 21 21 +1 +1 0.2 M 20 20 20 20 0 0 20 20 20 21 +1 +1 0.4 M 20 20 20 20 0 0 20 20 19 20 0 0 0.6 M 20 20 20 20 0 0 20 20 17 18 -3 -2 0.8 M 20 20 24 20 +4 0 20 20 18 19 -2 -1 1.0 M 20 20 19 18 -1 -2 20 20 20 17 0 -3 Table 3: Change in length Table 4: Average change in length Length of Apple Pieces (mm) Length of Potato Pieces (mm) Concentration of Sucrose Solution (Molar) Bottom piece Top piece Average change Bottom piece Top piece Average change 0.0 M +1 0 +0.5 +1 +1 +1 0.2 M 0 0 0 +1 +1 +1 0.4 M 0 0 0 0 0 0 0.6 M 0 0 0 -3 -2 -2.5 0.8 ...read more.

Conclusion

Whereas for the apples this point was around 0.4 M --> 0.6 M. since we did not use a concentration for 0.5 M we cannot tell whether that was the point at which there was little or no osmosis. As mentioned in the scientific knowledge when in hypotonic solution water moves in by osmosis from the solution and when in a hypertonic solution the water moves out into the solution. Between these two types of concentrated solution can be a solution that has a similar concentration to the cell and so water movement in or out will not happen this solution is called an isotonic solution (around 0.2 M for Potato and 0.4 M --> 0.6 M for apples). Evaluation The majority of this experiment went to plan, but it was only after analysing the results that I found that the measurement of length change was inaccurate. At the time of measurement I do not recall any reason to question that anomaly. In the future I would understand the problem that aim is investigating properly beforehand so I can be fully prepared for anomalous results and understand why they have happened and if I need to redo them. I am pleased with the mass change results since they followed what would be expected and didn't show too anomalous results. This allowed me to still get good and interesting graphs and conclusions and also helped me to better understand Osmosis as a process in biology. To make the experiment more scientifically valid I would put each potato/apple pieces in its own test tube so that we could rule out interference and get more reliable results. I would also use a wider range of sucrose concentrations do that we could obtain more conclusive results. To further understand osmosis it would be interesting to investigate which factors affect it. This could be done using temperature controlled water baths and refrigerators for temperature investigation. We could alter the size of the pieces we place in the solution the bigger the pieces immersed the greater the surface area. ...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

    Osmosis in Potatoes Lab. At which concentration of sucrose in water (% mass ...

    5 star(s)

    Once the concentration of the isotonic stage was found, then we are able to find the ratio of moles of sucrose to moles of water that is in the solution. In order to this, we found the molar masses of each (sucrose, water)

  2. Experiment investigating concentration of sucrose solution and potatoes

    Pat the potato dry. Then weigh it to see its mass, record this amount in a results table. I will weigh the potato to two decimal place, if the scale reads three decimal place I will round up or down.

  1. Osmosis Experiment Aim: To investigate the factors which affect osmosis in potatoes and ...

    * Time Left- If a piece of potato is left in the solution for a longer period of time more water molecules may have the chance to move across the membrane. * Cover- if there is a cover over the pot containing the potato and solution it could stop evaporation

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

    * Weigh each potato chip; using a digital balance the results can be recorded to 2 decimal places. The masses can be altered so that they are all equal by using a scalpel to shave off small slices. Record this measurement.

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

    To prevent this from happening we are going to take the potatoes out at the same time two days after putting them in their solutions. Volume of solution- This is fixed by using a measuring cylinder to measure the sucrose solution exactly.

  2. Use scientific knowledge and practical skills to determine the effect of a range of ...

    to survive, and in this experiment, it would be light and water. With both of these sources, the potato will keep on working until it dies of either lack of water or too much water, or will stop, as both sides would become equal, making no more reactions.

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