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Effect of temperature on membranes

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The effect of Temperature on membranes Aim: The aim of this experiment is to use beetroot to examine the effect of temperature cell membranes and relate the effects observed to membrane structure. Hypothesis: I think as the temperature increases, the absorbance will increase due to denaturing of the enzymes, making the cell surface membrane more permeable. Apparatus used: * Raw beetroot * Size 2 Cork borer * Knife * Ruler * White Tile * Plastic beaker approximately 250cm� * Forceps * Water baths at temperatures 10*C, 40*C and 60*C * Boiling Tube rack * 3 Boiling Tubes * Thermometer (one per water bath) * Colorimeter * 4 Cuvettes * Stopwatch * Distilled Water * Pipette to accurately measure amount * Small measuring cylinders * Water proof marking pen * Tongs Fair testing: To make it a fair test, we kept every variable such as: amount of distilled water used, size of the beetroot sections when cut, amount of time the beetroot was kept in the water bath. ...read more.


2) Next, using forceps to hold the beetroot sections, we washed each piece with water as we left it under a running tap for two minutes, removing excess dye. 3) After that, we poured 5cm� of distilled water into three boiling tubes and placed them into the water baths; one in 10*C, one in 40*C and one in 60*C 4) Then, we left the distilled water in the water bath for 5 minutes until the water reaches the required temperature. After this, we placed each section of the cut beetroot in each of the boiling tubes, leaving it in there for 15minutes. 5) Afterwards, we removed each beetroot piece from the boiling tube and shaked the tubes, dispersing the dye in the solution. 6) Later, we switched on the colorimeter and set it to read % absorbance. 7) Using a pipette, we accurately measured 2cm� distilled into a cuvette. ...read more.


In terms of physics, when you heat something up, it excites the molecules and causes them to vibrate more; in the cell surface membrane or plasma membrane the faster movement disrupts any ordered structure there might have been, eventually destroying the structure altogether. Improvements: If I was to do this experiment again, I would do it differently. To increase reliability I would collect more than three results, I would probably use 8 to 10 different temperatures and use more than one segment for each temperature (at least 3) and then collect an average. To increase validity of this experiment I could have used a size '4' cork borer instead of a size '2' to observe greater differences in levels of absorbance. Instead of running the segments under a tap I could have left them in a plastic beaker of distilled water over night, and them wash away excess dye and place them into the boiling tubes. Also, instead of placing the boiling tubes in water baths only for 15 minutes, I could have increased this to 30 minutes. ?? ?? ?? ?? ...read more.

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