Membrane permeability in beetroot cells.
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Membrane Permeability in Beetroot cells Beet root cells contains a red pigment, which is found in the cell vacuole. The vacuole has a membrane in which its function is mainly to prevent the betacyanins from leaving the cell. Leakage of these betacyanins into the external solution can be used as an indication of membrance pereambility changes. As part of my experiment, my aim is to see if temperature affects the membrane by witnessing the amount of betacynanins that leaks from the beetroot cells. The cell membrane covers the outside of a cell and consists of a double layered sheet of lipid molecules interspered with proteins. It seperates the cell from the external environment, gives phyisical protection and allows the import and export of selected chemicals. Aim: I will commence the experiment by placing beetroots in a test tube of deionised water, I will use a range of temperatures in which I will place the beetroot cell to see the damage later on. After placing them in series of test tubes of deionised water for 30 minutes. ...read more.
Otherwise this will create an error in my experiment. Therefore using a measuring cylinder enable my experiment to be fair and accurate. Apparatus: * Goggles, Ruler * Lab coat Colorimeter * Beetroot Petri dish * Cork borer Tile * Marker Spatula * Test tubes * Labels * Test tube holder * Deionised water * Thermometer * Measuring cylinder * Cuvette Fair Testing: In this experiment, a fair testing is crucial, as it will indicate whether my results were accurate or inaccurate. I must also ensure all factors are kept the same throughout my practical. Results: Membrane Permeability Table Beet root number Temperature (degrees Celsius) Colorimeter (% Transmission) 1/ % transmission 1 80 64 0.015 2 61 75 0.013 3 42 87 0.011 4 23 96 0.010 5 10 100 0.01 Conclusion, improvements and Evaluation: My experiment is now complete, and I have witnessed a pattern in my observations. Which is as the temperature decreases, the colorimeter (% transmission increased). For example "80°c, percentage on the colorimeter read 64%" and "61°C, Percentage on colorimeter read 75%." ...read more.
The beetroot cells did not stay in the test tubes for 30 minutes approxiamately. This could mean the colour may not have had enough time to diffuse out of the beetroot cells. Hence creating an error in my observations. An error could have also risen from the fact that the beetroots not washed properly . It was also important to have washed out the pigment from the cells that were damaged when using the cork borer. The anomaly I would say was the sample that was placed in a 5°c bath. Which gave me a relatively large percentage of beetroot pigment concentration, due to the fact that the cell membrane could not work at such a cold tempertaure, hence therefore the pigment (betacyanin) was easily diffused. On the other hand despite the fact I made a number of errors during the practical and the fact that I did the experiment alone and was under pressure to complete the practical on time. I can truthfully say I did this practical to the best of my ability. I believe with more practise, I will get the hang of it and next time I would be able to produce a better results. Donald Blankson Hemans - 1 - ...read more.
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Here's what a teacher thought of this essay
A weak experimental report that lacks the depth required to gain good marks in an A level course. Although some results were obtained the key sections were either missing or lacking in key details.
Research and Rationale
There needs to be background research carried out and discussed with respect to the likely effect of temperature on the components of a plasma membrane. The references used to inform the plan should be cited.
Although a list of apparatus was present there was no written method and no risk assessment. The key variables need to be listed and the way they will be controlled explained. There was no pilot experiment carried out.
There were some results recorded but no replicates were carried out. The table headings were unclear in some cases.
Interpreting and Evaluating
The interpretation of the results was not linked to biological knowledge and the limitations of the results were not fully discussed. The evaluation was mainly a list of personal failings with regard to measuring and lack of time which would fail to gain credit. The student would need to look more critically at the method ( unfortunately not in the report) and discuss ways that reliability could be improved or the investigation extended.
Marked by teacher Stevie Fleming 01/01/1970
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