3% Hydrogen Peroxide-This reactant needs to be measured out before being placed in the conical flask.
Thermometer- Used to check the temperature of the water baths.
The experiment reflects enzymes and how they work at certain temperatures and if I see that certain temperatures cause enzymes to malfunction, I could try to modify these temperatures so the enzymes would be able to work more efficiently.
I did a practical so I can prove that there is oxygen being produced. I took off the gas syringe and put the tubing in a second conical flask which is empty. The proof that oxygen was created was that I got some lint, made it into a weak glow and when I placed it into the empty conical flask, the glow turned into a flame. This proves that there is oxygen being produced. If I weren’t sure that it was oxygen I would know it’s a gas that’s being produced due to that when the hydrogen peroxide reacts with the catalyse, bubbles are produced meaning there’s a release of gas.
The practical is very important, and must be done in a way for which nothing’s odd out. Firstly, I would prepare variables in the experiment; after doing so, I would check the temperature of the thermometer which is in the water. After checking, I would measure out the amount of hydrogen peroxide required to be used. Once accurately measuring the hydrogen peroxide, I quickly remove the cling film, place the bung over the flask and I would start the clock watch. Just before adding the H2O2, I must be holding the gas syringe. When the clock reaches up to X amount of seconds, I would then read the results from the gas syringe for which I am observing and jot them down. This would be carried on throughout all the tests.
It’s helped in a few ways which are quite important. Firstly, there’s the temperature I recorded and at a high temperature such as 60˚C or 70˚C, the results from the gas syringe were quite low and possible dangerous due to that it could surpass the measuring limit thus making it unable to read results off. When there were cold temperatures such as 20˚C and 10˚C, the same results occurred. The time I recorded was quite non-useful due to that at 30 seconds, there were multiple readings; this tells me that I didn’t give enough time for the reaction to fully take place. When I used 1minute, the results were much understandable compared to the results on 30 seconds. Another variable of the results is the quantity of H2O2 and how much oxygen it produced. With 20ml, the readings for 1minute seemed to be too high and could be a threat to our future testing due to that the amount of oxygen could go over the gas syringe’s limit so I’ve decided to do 10ml. An interesting result from the table was at 80˚C where nothing was produced; maybe I could do temperature of 0˚C and see what happens then, to see whether anything is produced then. There will be a trial of three tests to make sure that they would be identical, thus indicating that the test has been fair throughout and to make it even more convenient, I will the average of the three trials for analysing results.
With a simple table, I’ll be able to input all my results and would be easy to read. This is a design of the table I wish to use in future tests.
I’m collecting how much oxygen is produced in 1minute and I would be only using 10ml of H2O2 to get fair results.
The results could be reliable depending on whether I enable fair testing; if I do so, I’m guaranteed to have understandable and easy to read results but supposedly the fair test was not followed, results could be changed to something which wouldn’t make sense.
I’m going to repeat the experiment two times just to make sure that the results seem fair and what I will do is that I will make an average so it’ll be better to work with rather than 3 results.
The following variables will be controlled to assure a fair test:
The most important part of the fair test would be two things; accuracy of the measuring. The liver must be carefully weighed as well as the H2O2 being measured and when using a measuring cylinder, your eye must be in level with the required measurement; if measurements weren’t accurate, our results could be modified, ending up with less or more oxygen being produced. Secondly is the gas syringe, I must be holding it due to that if it’s left on the table, then the oxygen may not properly push the top back properly due to the friction and this as well could ruin our results. Thirdly would be leaving the liver in the water baths, but if the water baths are at high temperatures such as 50 or so, then you should take it out but quickly and as well as not holding it for too long due to that our hand are at around 30 and the heat from the conical flask would transfer to us. Another important variable for a fair test is to place the bung on ASAP otherwise oxygen would escape, causing a change in our results. For the timing, when I add the catalyse I would instantly start the time and I would have to observe the timer counting down a few seconds before I have the time to observe the readings from the gas syringe.
My prediction is that if the temperature goes over 50˚C, the rate of reaction will start to strongly decrease as well as the temperature being at 20˚C.
Here are the results:
As I can see from the results, the trials are quite close in numerical terms, telling me firstly that each test was fair and I even had the same results at certain temperatures such as 80˚C where you have two 1ml volumes and as well as 50˚C with two 55ml. In my view the results seem to be very reasonable and the data seems to be quite accurately spread out from 61ml to 0ml making it a wider range. What I saw was quite accurate, the fact that the gas syringe was held properly and the preciseness of the timing but the strange thing is that the averages for 10˚C and 20˚C are identical though the results differ.
From the graph we’re able to see that from 10˚C to 40˚C, the amount of oxygen produced kept on rising but˚ after 40˚C, the volume started to decrease and ended up as 1ml on 80˚. By looking at the highest amounts and lowest amounts oxygen produced, I can determine what temperature allows the catalyse to work at top speeds and the slowest speeds. By observing the graph we can see at 40˚C the volume of oxygen produced was at 59ml but as well as that, we can see that from 10-60˚C, the volume decreases but not by too much; an estimate would be about 15-17ml whilst after 60˚C, it greatly decreases. The highest temperature we see is 80˚C and that only produced 1ml of oxygen but 70˚C also had a poor release of oxygen, only being at 29ml. If I think about this, the human body is at a temperature of 37˚C and the catalyse can still cope at 60˚C but why? If we think about it, the enzyme is misshaping but due to the energy that the heats providing, we can still see the reaction happening and with a volume that was 10ml less than the 40˚C volume which was 59ml. At 80˚C, the catalyse is very close to completely deforming, creating just 1ml of oxygen or even none so if we think about this, I’d say at about 83˚C would make it completely deform but due to that I haven’t tried this experiment, it’s only a rough estimate. 10˚C and 20˚C seem to have the same averages but I think that due to the cold, there’s not much energy to be used but 20˚C still has more heat energy than 10˚C but maybe colder temperatures below 30 will start to make the enzyme deform so the enzyme adapts to temperatures that are close to 37˚C otherwise after these temperatures, the amount of oxygen produced will decrease greatly. What if I done 0˚C, what would that show? Would the same of oxygen be produced as it did 10 and 20˚C or even a lower volume?
In conclusion, catalyse works at high temperatures and also at lower temperatures but works best at 40˚C which is actually near to body temperature. As well as this, it can work from 10-60˚C but works normally around 30-50˚C and when it’s around 10-20˚C, the volume produced seems to be quite similar whilst when the temperature is over 50˚C, the volume starts to decrease greater every time the temperature goes up by 10.
Overall, the whole experiment was quite interesting and especially the results. Everything was exactly precise such as the results, the practical work and the graphs. The analysis results seemed to be quite remarkable due to that the amount of oxygen produced was the same amount for two, low different temperatures whilst on high temperatures the volume kept decreasing. I would like to know what if the reaction took place at 0˚C, would it be the same as 10 and 20˚. It was interesting to see how much just 10˚C can affect an enzyme because during 60 and 70˚C, there was a dramatic drop of oxygen being produced meaning that the enzyme was deforming more and more and at 80˚C there was only one ml being produce. Probably, the improvements for the procedure were the fair testing. I think that at the temperature of 80˚C the enzyme should not function at all (fully deform) and I’m quite surprised that only 1ml of oxygen was produced but I think that 1ml might of came from a previous trial. Another improvement to make is the results and strangely enough at 10 and 20˚C, both should show different readings of oxygen but they were both quite similar in the trials and the averages were the same but my evidence to support this and the hot temperatures was reasonable enough to back up these odd happenings. If I had the chance to do this experiment again, I would like to change certain things and see whether I would get different results such as the liver type which could affect the rate of the reaction (causing greater/lesser production of oxygen), the temperatures would be a greater range so I would be able to find out what’s the lowest temperature that causes the enzyme to deform as well as high temperatures and also using different substances rather than hydrogen peroxide such as potatoes that also contain catalyse or even make the hydrogen peroxide at different temperatures and time it to see if it goes quicker and slower and also to see whether it produces the same quantity of oxygen or different. Once I started doing the research for the introduction I started to understand the structure of catalyse and began getting used to it.