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Determine what effect with an increase in the surrounding temperature has on the plasma membrane of a beetroot cell structure.

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An investigation into how the the temperature affect the permeability of cell membrane Aim: This experiment aims to determine what effect with an increase in the surrounding temperature has on the plasma membrane of a beetroot cell structure. Introduction: The purpose of a cell membrane is to control the transport of substances moving into and out of a cell. The membrane is an extremely thin layer (8 to 10 manometers (nm)) thick, which is partially permeable. It consists mostly of lipids and proteins. The lipids found in cell membranes are phospholipids because they have one molecule of glycerol chemically linked to two molecules of fatty acids and a phosphate group. Despite there are many differences in appearance and function, all cells have a surrounding membrane (called the plasma membrane) enclosing a water-rich substance called the cytoplasm. All cells have a variety of chemical reactions that enable them to grow, produce energy, and eliminate waste. Together these reactions are termed metabolism . In the cells of a beetroot plant, a substance called anthocyanin is contained within the cell, inside the plasma membrane. It is anthocyanin, which gives the beetroot its characteristic blue/purple colour. If a cell is damaged in a beetroot plant and the membrane is broken, the anthocyanin 'bleeds' from the cells like a dye. It is this characteristic that can be exploited to test which conditions affect the integrity of the cell membrane. Because I am experimenting with the effects of temperature on the membrane, i will place the samples of beetroot into a water baths of varying temperatures and measure the colour change in the water. Temperature is just one of the possible variables. ...read more.


Distillated water: this is used to provide a place for the reaction. Tissue paper: it is to dry up the beetroot. Needle: it is used to held the beetroot in place so as to increase the surface area. Thermometer: it is used to measure the temperature of the surrounds under the investigation. Colorimeter: it is used to measure the transparency of the solution. Water bath: it is used to provide different temperature for the investigations. Test tube rack: it is used to hold the hot test tube. Methods: 1) Before the experiment can start, the beetroot with the same size must first be prepared. To do this, we need the white tile, knife, glass rod and the corers. 2) The same diameter corers are made by pushing the corer into the beetroot and then withdraw it. The cylinder will remain inside the corer, so it must be pushed out with a glass rod. The entire beetroot piece must have the same surface area so as to have fair test. 3) Once a few good, uniform cylinders have been collected, they must then be cut into 15 pieces of equal length. The beetroot was cut to 2cm. 4) Because the beetroot has been cut some of the cell membranes had been broken, which means some anthocyanin will leak out. This must be completely washed off in order to maintain the reliability of the results. 5) Place a test tube into the beaker with hot water in it and put it into the water bath where the water bath must have been heated to 85�XC (the maximum temperature for our experiment) I can measure the temperature by using the thermometer. ...read more.


It is these findings which explain why cells cannot maintain life in extreme temperatures. Evaluation: The results that were collected follow the same pattern as results collected by similar studies carried out within our class, so therefore it is safe to say that the results can be repeated reliably and the methods can be used universally. It would have been beneficial to have repeated the experiment more times to make certain that the results were not gained through chance or by an external factor. The control experiment used was highly accurate, using distilled water, which is the clearest possible liquid, meant that even the slightest deviation in colour could be detected by the colorimeter. Controlling the variables in the experiment is not an easy task. The first major problem is the size of the beetroot piece. The pieces could be the same mass, but have a very different surface area to one another. This obviously alters the effect of the experiment. The other difficult variable to maintain was the temperature of the heated water. With only basic equipment, keeping the water at the correct temperature was made a complicated task. External variables were well controlled. If the experiment was to be repeated, the use of a proper controlled water bath may be a consideration, and also a template made for cutting the beetroot pieces. Using a beetroot as the sample is not a good representation of the whole eykaryote group. Other cell membranes may have better or worse heat tolerance, some may not be affected at all, however, using a beetroot does give a good representation of the theories behind the plasma membrane and how it behaves. ...read more.

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