Then I added 5ml of 5% protease solution – there are plenty of enzymes to collide as the concentration is strong and it will make the experiment fast.Next I have placed in a water bath at 37°C for 2-3 minutes - 37° is the temperature at which human enzymes work best and 2-3 minutes are not enough for the enzymes to digest the whole jelly. I then pour the mixture through a filter funnel, timing how long it takes.
The experiment is repeated twice and I take an average – this is done to make the experiment a fair test and also to check if there were any errors in the first results.
Stages1-4 are also repeated for the other enzyme concentrations – this is to see if my hypothesis was correct.
Fair testing
In order for the experiment to be fair I need to be careful with the following factors which could affect my results:
- I must use the same amount of gelatine jelly each time otherwise my results will not be valid, the jelly also being my dependent variable
- I must make sure the jelly is the same size pieces otherwise is they’re different sizes it could affect the rate of reaction.
- I must use the same volume of enzyme solution each time,
- I must use the same filter funnel
- I must leave the solution in the water bath for the same length of time each time because if I leave them for too much or too less then the enzymes will either have digested too much or not had enough time to react.
- I must have the water bath set at 37°C each time if it goes higher then the enzymes will begin to denature and stop working properly.
- My independent variable being the enzyme solution.
Results
Conclusions
From the results, it is possible to conclude that the hypothesis I formed in my plan was correct. That is, as the concentration increased, so the rate of reaction increased. This happened since the enzymes were able to digest protein found in a different part of the surface area of the substrate. At higher concentrations, the rate increased more slowly. This is due to the fact that as the concentration increases, the substrate is covered in enzymes, and there is no more surface area to be covered.
Safety
The only danger of this experiment is when handling the ph Buffer which is an acid to help the enzymes work better. It is important to wear safety goggles all the time
I believe that the results I have show that my hypothesis is correct and that this method of testing supports it.
Sources of error
The gelatine wasn’t the same size chunks and had different surface areas, a larger surface area increasing the reaction and a smaller surface area would slow down the reaction. The effect that this had on the reaction was that the rate of reaction had been changed. A mold could have been used to measure each chunk.
The amount of time the enzymes were left in the hot water might have not been the same every time. If it was left more the enzymes would have digested more and thus changing the rate of reaction.
The equipment used to measure, the syringes we had to measure the low volumes weren’t as accurate as it could be to measure the small volume.
Evaluation
I believe that my experiment was successful in proving my original hypothesis. I think that the number of repeat results taken shows that the data obtained was reliable, since three repeat experiments is enough to prove the basic idea behind a hypothesis.
