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

Investigation into the effects of osmosis on Potato cells

Extracts from this document...

Introduction

Investigation into the effects of osmosis on Potato cells PLANNING AIM The aim of this investigation is to find out the concentration of cell sap in potato tissue. Variables * Controlled-Starting length will be as close to 3.00cm possible, starting volume, which is 20ml also the same time the potato cells are kept in solution and same conditions for each cylinder. * Dependant-Length of potato cylinder (before and after osmosis has occurred). * Independent-Concentrations of solutions which are: (m) 0,0.1,0.2,0.3,0.4,0.5 Solutions Vol. Of glucose * 0.5 = M (0.5 = starting glucose concentration) Total volume 1) 0 * 0.5 = 0 M 20 2) 4 *0.5 =0.1M 20 3) 8 *0.5 =0.2M 20 4) 12 *0.5 =0.3M 20 5) 16 *0.5 =0.4M 6) 20 *0.5 =0.5M 20 20 Prediction I predict that this experiment will have different results throughout all the concentrations. Osmosis depends on two concentrations; outside (glucose solution) and inside (cell sap). I feel that my experiment will prove that osmosis has occurred meaning the water has moved form a high concentration to a low concentration. But. If the cell was already turgid when we measured it, the movement of water from a higher concentration to a lower concentration means we will find the potato cell will shrink as the solution has moved out. ...read more.

Middle

Other instruments which were the measuring cylinders - 10 ml & 25ml that are accurate to *-0.1ml & *-0.5ml respectively. This helped when I had to measure out glucose solution and distilled water. This all helped to get accurate results & a successful experiment. Strategy for results For my results for the experiment, I will make a table with concentrations down the left side and lengths of potato cells along the top. Then the percentage change in length down the right side. The title will be - -Investigation into the effects of osmosis on potato cells: Results. The graph that I will plot my results will have Concentration of glucose (M) on the X-axis and % change in length on the Y-axis. On this I will draw a best-fit line. Above the X-axis, the results are Hypotonic and below the X-axis the results are Hypertonic. But if the results are on the X-axis line, the result is isotonic meaning the concentration inside equals' concentration outside. Table and graph overleaf To find the percentage change in length, I had to use the following formula: final length - original length original length * 100 (1) 0M; 3.12 - 2.96 2.96 * 100 = 5.405% (2) 0.1M; 3.14 - 2.98 2.98 * 100 = 5.369% (3) ...read more.

Conclusion

This might be anomalous because maybe the volumes measured inaccurately or the vernier callipers were read slightly wrong. This means if there was a mistake it was because of human error. How suitable was my procedure? I feel my procedure was well suited to this investigation, because 0.25M (isotonic) fell in between 0.2M and 0.3M, meaning a perfect experiment. Also the apparatus was good enough for a successful experiment. Any changes to improve? I fell that there are many changes I could do to improve my experiment to get more accurate results. And they are: 1. Be more accurate when cutting the cylinders, try to be as close to 3.00cm as possible. If we had two different starting lengths e.g. 3.02cm and 3.12cm it would not be fair because 3.03cm chip has a greater SA: VOL giving it an advantage in terms of osmosis. 2. A third potato cylinder could be cut and put into the specimen bottle to increase accuracy in getting results. 3. A burrette could be used. These are accurate to 0.1ml, which would help when we are measuring out our solutions. 4. Also Digital Vernier callipers would be useful as we could just read off the measurement and possibly eliminate human error when measuring. Does the evidence support a firm conclusion? Yes, because 0.25M (isotonic result) corresponds with book value so this is encouraging. Five of my plotted values follow the pattern and only one is anomalous. ...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

Here's what a teacher thought of this essay

5 star(s)

*****
This account shows attention to detail and good use of scientific language. There are a few minor errors.

Marked by teacher Adam Roberts 01/05/2013

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

    Biology Coursework - Osmosis

    5 star(s)

    same variety treated in the same way, i.e.: have all been cut with scalpel, and skins removed. Temperature To ensure the temperature doesn't vary, I will perform all the experiments at room temperature.

  2. Marked by a teacher

    Potato / Osmosis Experiment.

    5 star(s)

    and re-weighed. During the taking of these results, a sketch scatter graph was drawn which displayed the anomalous results that needed to be re-done. The line of best fit from this scatter graph also indicated the area where the isotonic solution was (which was stage 3 in my predicted graph).

  1. Marked by a teacher

    Osmosis in Potato Chips

    5 star(s)

    In osmosis, water molecules only ever move down the concentration gradient but in experiments we are likely to get a few strange results. To combat this and to help make it a fair test I am running 3 test tubes with the same concentration of sucrose for each concentration level.

  2. Marked by a teacher

    Plan: The effect of the end product, phosphate, on the enzyme phosphatase

    5 star(s)

    * The concentration of enzyme solution For enough substrates, more concentrated enzyme will result in faster reaction since there will be more enzyme molecules available to react with the substrates. To control this variable, enzyme from the same extracted solution is added to each test tube.

  1. Peer reviewed

    How the structure of cells is related to their function.

    5 star(s)

    this helps the sperm with movement on its journey to the egg. Fig 1 The red blood cells (RBC) are very different indeed unlike most plant and animal cells they have no nucleus when fully matured and no organelles except their plasma membrane and they are formed in the bone

  2. The effect of acid on the cell membrane

    water for 3 minutes to wash off any pigment that has been released. 3. Make up different concentrations of Hydrochloric acid using 1.0 molar acid and distilled water. I made up the concentrations as follows: * 1.0 molar used 20cm� HCl, 0cm� water * 0.9 molar used 18cm� HCl, 2cm�

  1. An introduction to osmosis.

    The equipment I will be using is: 1. Six test tubes 5. Measuring cylinder 2. Sugar 6. Filter 3. Potato 7. Scales 4. Potato corker 8. Test tube rack Stacey Owen Candidate no: 0126 Hampton Community College I will place the six test tubes in the rack. I will then label each test tube from 1-6.

  2. Find the concentration of Potato Cell Sap.

    When I look at the results more closely, I can see the following patterns or trends; As the concentration of the bathing solution increases in strength, the pieces of potato get smaller. At 0 and 0.1 M Sucrose, the potato grows, with 0 growing the most.

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