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The effect of temperature on the activity of trypsin.

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The effect of temperature on the activity of trypsin Method: To begin the experiment safety precautions were carried out, goggles and a laboratory coat was put on. A water bath had been previously prepared for us at 30c. Three test tubes were labelled '30c casein', '30c trypsin' and '30c control'. Using a pipette, 5cm? of casein suspension was pipetted into each of the test tubes labelled '30c casein' and '30c control'. Using another pipette to avoid contamination, 5cm? of trypsin solution was pipetted in the test tube labelled '30c trypsin'. And again, using a different clean pipette, 5cm? of distilled water was added into the test tube labelled '30c control'. The three test tubes were then placed into the water bath and left for several minutes to reach the temperature of the water (we tested this by placing thermometers in each test tube, we had to use three thermometers because if one thermometer was transferred from one tube to the other it would have contaminated and thus started the reaction). The enzyme (the trypsin) was then added to the substrate (the casein) and agitated to ensure that they were thoroughly mixed. This was then replaced in the water bath and a stopwatch was started immediately. The contents of the tube were then carefully observed (and every now and again the tube was agitated to keep the contents moving) ...read more.


0.0048 = 0.48 x 10 -2 Analysis: The two lines of my graph are similar and yet also different. At first both of the lines rise, this indicates that as the temperature is increased the time taken for the suspension to clear became less (the rate of reaction increases). But after a certain point they both differ; my personal line goes up, suggesting that the time taken for the suspension to clear became even quicker, but the class line goes slightly down, which suggests that the time taken for the suspension to clear was slower. My line shows a pattern in which as the temperature increases the enzyme activity increases. The class line shows that the activity of the enzyme will increase if the temperature increases, but only within a certain temperature, after that it will then start to decrease. Using my knowledge of the effect of temperature on enzymes I can understand why there are differences in my two lines. If other factors such as pH, enzyme concentration and substrate concentration are kept constant then temperature has an effect on enzyme activity. At the beginning, a rise in temperature will increase the kinetic energy of the enzyme and the substrate molecules, and will therefore tend to increase the rate of a chemical reaction. ...read more.


This is due to the fact that the lid was taken off of it and also more and more cold test tubes from each group were going into it so the energy went into heating the tubes up. A difference in temperature could affect the results of the experiment. * Some groups were treating the test tubes differently from others: after when the enzyme has been added to the substrate some groups remembered to regularly agitate them to ensure that they were still moving, other didn't mix the tubes thoroughly and were left with a substance that was clear at the top but still cloudy at the bottom. Some groups also accidentally contaminated the test tubes by using one thermometer for the trypsin and the casein. Considering all of these factors, it explains why my personal line was different from the class line. If this experiment were to be carried out again I would try and make improvements: 1. A shared water bath is not ideal as the temperature of the water bath will drop and affect the results. Individual water baths should have been used. The temperature of the test tubes needs to be accurate in order to produce accurate results and a graph. 2. The test tubes need to be agitated regularly, as the milk is denser than trypsin and could sink to the bottom of the test tube and also contamination needs to be avoided at all costs. ...read more.

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