Variables Effect Rate
There are four variables. They are:
- The PH value of trypsin
- The concentration of trypsin
- The volume of trypsin
- The temperature of trypsin
In this experiment I will only be testing for the temperature of trypsin. Therefore I will keep all the variables the same and only change the temperature of the trypsin. If I change the other variables they will affect the results of my experiment that is why I am not going to change them. I do not need to do anything to keep the PH the same as when we did the prelim work I tested the PH value before and after the experiment and it did not change. I will be keeping the same concentration of trypsin by using the same solution of trypsin for each experiment. I will keep the volume of trypsin the same by measuring out 10cm3 of trypsin for each experiment.
Background
A photographic film is made up of 3 layers:
Trypsin is an enzyme which catalyses the breakdown of Gelatin, when gelatin is broken down, there is nothing to hold the silver halide in place. The photographic film turns clear as you can see in the diagram above.
Aim
My aim is to find the rate of reactions of the enzyme tripsin at different temperatures.
Apparatus
- Thermostatically water bath
- 5 Boiling tubes
- 5 Thermometers
- 5 Stop watches
- 1% Trypsin
- Measuring cylinder
- 5 Splints
- 5 Photographic Films
- 5 Test tube racks
We used thermostatically water bath so we could get the exact temperature for our experiment, the thermostatically water bath is very accurate. We used 5 boiling tubes, 5 thermometers, 5 stopwatches, 5 splints, 5 photographic films and 5 test tube racks so we could do 5 experiments at the same time but at different temperatures. We used the measuring cylinder so we could measure out 10cm3 of the enzyme trypsin for every experiment; the measuring cylinder is suitable for this because it is accurate and would help us to keep our experiment fair.
Method
First of all we measure out 20cm3 of 1% trypsin using a measuring cylinder. Then we pour the trypsin into a boiling tube. We place a cork on top of the boiling tube (the cork has a whole in it) then we place the thermometer through the cork into the boiling tube. We place the boiling tube into the assigned thermostatically water bath. Then we wait couple of minutes for the trypsin to acclimatize to the correct temperature. As you place your photographic film you then start the stopwatch and every 30 seconds you must record the color of the photographic film in your results table. You do this until the photographic film goes clear, then you should stop the stopwatch and record the result in your table. You repeat the same method for all temperatures.
Fair Test
The experiment must be a fair test or I will be getting a lot of anomalous results and there may not be a clear pattern in the results. To make the experiment a fair test I am going to make sure that volumes of trypsin are the same in each experiment.
I will also need to make sure that the photographic film is completely clear before I stop the timer. When I think it is clear I will press the red button on the timer and if the film goes no clearer I will take the time that I paused the timer at. If it does go clearer I will continue the timer and stop it when it goes clearer.
Prediction
I predict that the enzyme will work good around 40 degrees, because this is the average human temperature and it is where the enzyme meant to work at its very best. After 45 degrees the enzyme will start to denature.
Diagram
This graph shows what will happen, if my prediction is right.
Results
As you can see in my results, the enzymes at 50&60 degrees denatured this tells us that part of my prediction was right. As you can see the higher the temperature the faster it is for the Trypsin to react with the photographic film. I would have repeated each experiment 3 times to get a good result, but I could not as we did not have enough Trypsin.
Evaluation
There appears to be no clear anomalous results. As my method and plan was to make the experiment a fair test and if I had made sure that the results were exactly accurate, the results should have been near perfect. But because I could not ensure exact measurement was used, this could be a possible reason for the slight inaccuracy in the results.
My prediction was right, I said that the enzyme will work good around 40 degrees and the enzyme denatured at 45 degrees. If I had the chance I would redo the entire experiment, as I could not do it properly because we did not have enough Trypsin. I would also repeat my experiment more then 5 times just to make sure I get nice results. My results are not very reliable as they are not accurate. I think my method was suitable for this experiment it was very simple.