Apparatus
In the preliminary experiment and the main experiment I am going to use the following elements:
- 5 Test Tubes – 4 to hold the main solution and 1 for the control.
- Water baths – For the different temperatures – holding test tubes.
- Stop watch – to time the acclimatization period and then to time the regular intervals for the photographic film.
- Split-ended splint – To hold the photographic film to dip into the solution.
- Photographic film – To dip into the solution and check for reaction.
Safety
There are a few safety procedures we must follow:
- Stay far from the solution as enzymes cause stains.
- Where goggles at all times.
- Do not splash the photographic film in the solution.
Hypothesis:
I think the results will show that the enzyme will work right up until about 37 degrees Celsius. It will work fastest and most efficiently just below the body temperature and at that temperature because this would be its optimum temperature. After this temperature, the enzymes will become denatured and rapidly stop working. I also think that the enzymes will become denatured at around 20 degrees Celsius, because most body temperatures do not fall below that.
Control Variables:
Before doing the experiment there are a few things we must control to ensure that we are conducting a fair test. The volume of trypsin in the test tubes must be exactly the same; we must use accuracy in his as even a slight change in the volume can change the results. The concentration must also be the same for all the test tubes. The water in the fifth test tube must also be the same volume as the trypsin to make it an even fairer test. The temperatures of the water baths must also be the as accurate as possible, with the water content inside them being the same. This should be the same because different volumes would then take different times to acclimatize or even boil. The PH levels must also be kept at 7 for all the test tubes. To ensure this we are to develop a buffer solution, which will be dissolved inside the trypsin. The buffer solution will control the PH level. Extreme PH’s can cause the enzymes to become denatured. The photographic film that we are to use in the experiment must be of equal surface area. This is because a large surface area would take even longer for the photographic film to become clear. When we take the photographic film out, we must take it out at regular intervals – the same period of time for each test. The amount of exposure the photographic film gets must also be the same for each photographic film. This is to ensure that some photographic film don’t get any longer time in the solution than others.
All these must be completed to accuracy to ensure that we perform as fair test as possible.
Preliminary Test
The preliminary test is done to find out the best acclimatization period for the test tubes. First we added 5cm3 of trypsin which already had buffer solution dissolved to maintain the neutral PH. We filled another test tube with water. We got each test tube and placed each one in its own water bath with different temperatures. Firstly we let the test tubes acclimatize for 3 minutes. After three minutes we placed the photographic film inside each test tube and left it. Every 20 twenty seconds we checked the photographic film to see if it had gone clear. If it had gone completely clear we knew that the reaction had taken place. They were unlikely to react after just 20 seconds, therefore we kept checking every 20 seconds for long periods of time. After doing this once, we were able to do this again and this time we changed the acclimatization period to five minutes. By changing it the enzymes had more time to know their environment so they could work better. The results table below show what acclimatisation period was better and the one that should be used for the main experiment.
Preliminary Test Results
Conclusion
The results of the preliminary test have shown five minutes to acclimatize the trypsin is enough time. Three minutes was too short for the trypsin to acclimatize and the results have shown that the enzymes became denatured because the length of time for the reaction to take place was inconclusive. When the acclimatization period was five minutes long the reaction took place within minutes. This experiment also showed that
Method for Main Experiment
The main experiment will be done firstly by adding 5cm3 of trypsin to 4 test tubes. To maintain the PH level at neutral (7), a buffer solution will be dissolved in the trypsin solution. We filled another test tube with water for the control experiment. We got each test tube and placed each one in its own water bath with different temperatures. Firstly we let the test tubes acclimatize for 3 minutes. After three minutes we placed the photographic film inside each test tube and left it. Every 20 twenty seconds we checked the photographic film to see if it had gone clear. If it had gone completely clear we knew that the reaction had taken place. They were unlikely to react after just 20 seconds, therefore we kept checking every 20 seconds for long periods of time. After doing this once, we were able to do this again and this time we changed the acclimatization period to five minutes. By changing it the enzymes had more time to know their environment so they could work better. The results table below show what acclimatisation period was better and the one that should be used for the main experiment.
Results