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Enzyme investigation

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Charlotte Mortlock Enzyme investigation Dec 01 In this investigation we are trying to find out how variables affect the rate of oxygen and water produced in hydrogen peroxide. The enzyme that we are working with is called, catalyse. This can be found in living things, for example- it is found in the human liver. As we know there are all sorts of enzymes, all uniquely designed to break down, different substances. Our enzyme, catalyse, is designed for the breaking down of a toxic substance, known as Hydrogen Peroxide, into water and oxygen. The chemical equation for this is- 2H2O2 ? 2H2O+O2. Catalyse is also present in yeast. We will be using yeast that has been immobilised into beads. We will be looking at the possible variables, and deciding on our chosen one. The variable will help us to investigate what affects the speed of reaction. The possible variables are- * Temperature * Size of beads * Concentration * Ph Our chosen variable is the first one, temperature. In order to produce the appropriate amount of results for this investigation, we will be filling five test tubes with hydrogen peroxide, obviously each tube will be at a different temperature, and adding the yeast beads to the solution. ...read more.


Hydrogen peroxide, as I mentioned before is a toxic substance, and therefore we will be very careful when handling it, and will try not to let it come incompact with us, or any of clothes. Whilst everyone's, (not just our own) experiments are being carried out, we will wear safety glasses, and will be sure to keep them on at all times. We will be careful when handling hot, maybe even boiling water, and will ensure that we clean up all spills or breakages and inform a member of staff about them. In order to make this investigation a fair one, we will change only the one variable, and will stick to it throughout the investigation. We will use 5 test tubes , making sure that they are at the same size, and will be measure the concentration of the hydrogen peroxide as accurately , and as close to 10ml as possible. We will try to keep the beads as close to the same size as possible, although to get them exactly the same is near impossible at school! We will take three results, and record an average, this will give us a more accurate result, and it will be fairer then just testing the once. ...read more.


We, due to only having an hour each lesson, had to carry out the test over two lessons, we were fortunate however that these lessons were on two consecutive days, and therefore the beads did not change much over this time. We were very accurate, and patient when taking the temperature, however the small time between checking the temperature of the solution, and then carrying out the test, gives time for the temperature to fall slightly, but this is something we could not really avoid. The last, and maybe the biggest factor was the size of the beads, however as I said before, getting the size exactly the same I near impossible, but we did look carefully at each bead and check that its size was reasonably close. I think, including these factors, that our results are suitable and reliable, and show us what we had aimed to discover, how a chosen variable can affect the rate of reaction. I think that they are sufficient to support a firm conclusion. If we were to repeat this experiment, with the same amount of time taken into consideration. I don't think I would change the way we carried it out, as our method was stable, and helped us come to the appropriate conclusions, I would probably just be more careful when measuring and checking temperature's and concentration. ?? ?? ?? ?? ...read more.

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