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Beetroot experiment. Aim: To investigate how the temperature affects the permeability of beetroot cells and membrane structures.

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Aim: To investigate how the temperature affects the permeability of beetroot cells and membrane structures. Apparatus: * 4 cuvettes (to pour dye solution into, that will then go into the colorimeter) * 4 test tubes (to put water and beetroot into) * 4 water baths (to set at a particular temperature, and to place test tubes of dye solution into) * 4 thermometers (to measure to temperature of the water into the test tubes that are in the water baths) * 1 raw beetroot (to test the effect of temperature in the beetroot structure) * Colorimeter (to measure the amount of light absorbed in the dye solution) * 1 scalpel (to cut the beetroot) * 1 ruler (to measure sizes of beetroots, that will be cut) * 1 measuring cylinder (to measure distilled water that will go into the beaker) * Pipette (to measure amount of water that will go into the test tube) * Distilled water (to mix with the beetroot and test its absorbance of light) * 1 tile (to cut beetroot on top of) * 1 plastic beaker (to put distilled water and beetroot pieces into to wash off any excess dye) * Marker (to mark all test tubes as to prevent contamination) * Clock (to measure how much time the beetroot was in the distilled water for) Safety: For this experiment standard laboratory safety precautions must be used, for example carrying steadily liquids this is because the water could cause injury in the form of burns, if this is to happen you must run the burnt part with cold water this will then reduce the temperature of the burnt area and reduce the pain and burns in the long term. ...read more.


* After 5 minutes insert the raw beetroot samples into separate test tubes and fill the test tube with 5cm3 of distilled water. * Now place the labelled test tubes each in a water bath of different temperatures and leave them all for 15 minutes, also check the time with a stopwatch, you must start the timer as soon as the test tubes are in the water bath, as if you are to start the timer too early or too late there may be a variance in temperature which would cause unreliable results to appear. * After around 14 minutes, place a thermometer in the test tube to check if the distilled water in the test tube is the desired temperature. * After 15 minutes have finally past, take out the test tubes from the water bath. * From each test tube take, in accurately 2cm3 of water from the test tube using a pipette and pour the dye solution into a cuvette. * Set the colorimeter to read 0 absorbance for clear water, the setting must not be altered again during the whole experiment as this could cause inaccurate results for example if the colorimeter starts at 10 instead of zero the readings that you take will be of a absorbance of 10 more than it should be, which will give you unreliable results. * Place the cuvette into the colorimeters slot and place the black cap on top, so that no light may enter, you must do this as if light were to enter this may cause unwanted fluctuation in your results as the light intensity will alter the absorbance. ...read more.


the beetroot sample i used may have been contaminated which may have affected the transmission and thus the reliability and accuracy of my results. Furthermore if i was to redo this experiment i would also a greater variance in temperature for example the temperatures i used mainly went up by around 10 degrees, but if the temperatures went up by 5 degrees i would be able to have more precise and accurate results as i would get a better average and would make my conclusion more secure. Moreover, as another improvement to my experiment i would leave the sample of beetroot in the beaker of distilled water for more than 5 minutes to remove any excess dye, i would do this because in 5 minutes i do not believe that all the excess dye would be removed so if i were to redo this experiment i would leave the beetroot in the dye for 1 day, it is important to wash off any dye, as any excess dye will affect the transmission thus, giving me outliers in my results. I could also do more work by seeing how pH level affects membrane structures. For me to be able to do this I would leave the beetroot in different pH's for 30 minutes and then use a colorimeter to measure the light absorbed by the dye that has been released from the beetroot. All in all, from this experiment i have learnt that an increase in temperature breaks down the membrane structure which in turn causes an increase in the amount of dye released from the beetroot. ...read more.

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Here's what a teacher thought of this essay

3 star(s)

Overall, this assignment suffers to some degree from a lack of clarity in the use of scientific terms. As already mentioned, it is vital for A'Level students to be confident in their understanding of terms such as accurate, reliable and valid.
The report needs a clear aim and hypothesis. Without these, it lacked clear focus.
It also lacked the required depth of biological knowledge needed to analyse the data.
It is vital that assignments are checked by the writer before being submitted to ensure that sentences make sense and any grammatical errors eliminated.
The overall investigation did, however, generate some useful data that could have led to some valid conclusions.

Marked by teacher Ross Robertson 01/03/2013

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