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To Investigate the Course of an Enzyme controlled Reaction.

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Biology Coursework To Investigate the Course of an Enzyme controlled Reaction Introduction For this investigation, I am going to investigate the effects of varying the concentration of an enzyme (diastase). I am going to react the enzyme, diastase, with a starch solution at different concentrations and record all of my results. I believe that as the concentration decreases then the rate of reaction will decrease and as the concentration increases the rate of reaction will increase also. However, if the enzyme concentration continues to increase, then it becomes saturated and the reaction remains at the saturation level. This occurs, because all of the substrate molecules have active sites to bind to, and therefore increasing enzyme concentration further will have no effect. From these results I will initially be able to see if the enzyme concentration has any effect upon the rate of reaction. I will then, observe my results more specifically and in more detail analysing anomolies and general trends. I will record all of my results and plot them on appropriate graphs which I will hopefully be able to obtain a fairly strong conclusion. Finally, I will evaluate my experiment and results commenting on any errors observed, and what improvements can be made to make the experiment more accurate. Prediction I predict that as the concentration decreases then the rate of reaction will decrease and as the concentration increases the rate of reaction will increase also. ...read more.


transmission value. Record your results in a table. Repeat this process two more times at the same temperature and diastase concentration to get a more precise average. Then, repeat the whole process using concentrations of 1%, 0.8%, 0.6%, 0.4%, and 0.2%. NB: *When repeating the reaction using different concentrations, the amount of diastase will change accordingly, and different volumes of water will need to be added to do this. Refer to the table below. 5cm� total Diastase H O 1% 5cm� 0cm� 0.8% 4cm� 1cm� 0.6% 3cm� 2cm� 0.4% 2cm� 3cm� 0.2% 1cm� 4cm� Conclusion From my results, I can see that generally my prediction was correct; that as the enzyme concentration decreases the time taken for the reaction to complete drecreases also. This is due to the fact that when the diastase solution becomes diluted, there are less enzymes, and therefore less active sites for the substrate to bind to. This in turn, does not effect the amount of starch broken down, but the time it takes to do so. From the graphs, we can see that when the diastase was 1%, the reaction was complete almost immediately. It only took three - four minutes for all of the substrate to be broken down by the enzyme. However, when the concentration of the enzyme was 0.2%, in two of the experiments, the reaction was not complete after ten minutes. ...read more.


This is because, although there are few anomolies in the results and that for each experiment, I carefully and correctly followed my own method the time measure bwteeen each sample was too large to get accurate results. To make the results more accurate, I believe I should follow my method except, I would change the time measures from one minute to thirty seconds. When completing my experiment, as well as my errors, there were apparatus limitations which may effect my final results. For example, when extracting solutions with the syringes they are not 100% accurate and mistakes can easily be made. I may have unintentionally taken slightly under or slightly over the stated volume and will therefore effect my final results. Because my apparatus is fairly basic, I used a manual stopwatch to tell me when to take out the diastase and starch solution. Although it is to 100th of a second, it is not exact and precise. Therefore everytime I extracted the diastase and starch solution it will not have been exact each time. A buzzer, or an alarm every thirty seconds may help to improve this. Also, I had to warm the enzyme and starch in seperate beakers, and then mix them together. This wasted valuable time and small droplets of the solution may have been left on the inside of the beakers. The waterbaths, also, were not at exact temperatures. Although they were set to specific temperatures, the thermometer stated that it was slightly under. ...read more.

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