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altering the enzyme concentration

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AIM: To investigate the effect of altering the enzyme concentration upon the rate of reaction. The enzyme used is amylase and its substrate is starch. PLAN: For this investigation I am going to investigate how the concentration of amylase can effect the time taken for the starch to fully breakdown. I shall do this by varying the concentrations of my enzyme (amylase) while keeping the substrate (starch) constant throughout the reaction. I must also keep other variables constant throughout the experiment. Temperature is one very important variable that must be kept constant throughout the whole experiment. If not, there will be either an increase or decrease in rate of reaction which will cause a great impact on my results. If the temperature increases the amylase and starch molecules will begin to move faster due to kinetic theory. The molecules will then come into contact with each other more often and will cause an increase in rate of reaction. However, if the temperature increases too high it will cause the enzyme to denature, due to heat as enzymes only work best at about body temperature, and this will completely stop the enzymes working and therefore the breakdown of starch will also stop and thus causing the rate of reaction to stop and decrease. ...read more.


Also I might need goggles just for safety if needed, however, when using iodine goggles must be worn, as iodine can be irritable to the eyes. When we first tried out the experiment using 0.1g, 0.2g, 0.3g, 0.4g, 0.5g of amylase it took quite some time to obtain a reaction and therefore we changed the masses to 0.01g, 0.02g, 0.03g, 0.04g, 0.05g and it gave us reasonable results. Therefore we selected masses of amylase around these figures. We were given a little bit more enzymes to get these measurements as the 2g that was given to us at the beginning had finished so we needed more to obtain new measurements. We also tried out certain measurements for the substrate solution. We used 5g of starch with 20cm� of distilled water; however, this quantity was not good enough as it caused a very slow reaction. It caused a slow reaction because there was more substrate for the enzyme to break down. Therefore more time was needed for the reaction to be completed. There were also another two slow reactions taken place when we used 2g of starch with 20cm� of distilled water and 1g of starch with 20cm� of distilled. ...read more.


My results are reliable but if I had repeated them more than I did then of course they would be even more reliable...the more the repeats the more reliable the results! But in general my results are good enough...they support both my prediction and the scientific knowledge that I have obtained. If I were to do an extension to my experiment I would vary the temperature as this variable has an enormous effect on an enzymes rate of reaction. This is because enzymes can only react or become activated at certain temperatures (body temperature - between 35�c to 37�c), and if the temperature is either too low or too high the enzymes will not respond. If the temperature is increased too much then the enzymes will become denatured and will not be able to work what so ever...also if the temperature is too low it will become frozen and again will not be able to work. So I believe that this variable, temperature, is also a very good variable to vary in an enzyme experiment. There are a few more variables that could be used as an extension, such as the Ph of an enzyme, the substrate concentration etc. all of these factors have great effects on enzymes and their rate of reactions. ...read more.

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