Prediction
I predict that as the temperature gets higher, the activity of an enzyme will increase. This is due to the kinetic theory that when there is more energy (in this case heat) the molecules will move faster at a higher temperature so there will be more collisions, because there are more collisions, there is more chance of the enzyme hitting the substrate so it will get digester more quickly. Also, I think that when the temperature gets to over 60 degrees Celsius, the enzyme activity will dramatically drop. This is because the enzyme will begin to get de-natured and the ‘Active Site’ will be out of shape so the reactions will the substrate cannot take place. I predict that he optimum temperature is around 37.5 degrees Celsius because that is the temperature in our body.
Apparatus
1) Boiling Tube – to carry out the experiment.
2) Trypsin – Enzyme.
3) Milk – Substrate.
4) Water – to mix the milk powder.
5) Stopwatch – To time the experiment.
6) Measuring Cylinder – To measure the amount of Liquid needed.
7) Thermometer – To measure the Temperature of the solution.
8) Water bath(s) – To heat up the solution.
Variables
1) Temperature (Will be changed)
2) Volume of Enzyme (Will not be changed)
3) Volume of Substrate (Will not be changed)
4) Concentration of Enzyme (Will not be changed)
5) Concentration of Substrate (Will not be changed)
6) pH (Will not be changed)
For an Enzyme to work, there are many environmental factors that need to be dealt with. The temperature and pH could affect the outcome of this experiment.
In temperature, there is a temperature in which the enzyme works at its optimum rate and also a temperature in which the enzyme de-natures and it just stops working. With pH, if it is too high or too low, it will affect the Hydrogen bonds in the enzyme. So the pH needs to be perfect for the enzyme for it to work at the optimum rate.
The concentration of the enzyme and the substrate needs to be taken in account and they will be kept the same throughout the experiment to ensure a fair test.
In this experiment, only the temperature will be changed. This will be controlled via water bath, which can increase or decrease the temperature. The same solution of enzyme and substrate will be used throughout the whole experiment; this ensures the concentration of the substances to be kept the same. The pH should be kept the same but there is nothing to keep it at a constant like a buffer solution.
Other Factors
Apart from the Variables above, there is other factor that might affect the outcome of this experiment. Human faults will affect the results, we may be undecided to whether the milk is clear or not. Also, the amount of Enzyme/Substrate poured out could be measured inaccurately; this will affect the results. Also, residue inside the boiling tubes may affect the speed of the reaction so the results might be inaccurate.
To minimise these factors from affecting the experiment, the experiment will be carried out care fully and will be repeated twice each and the average will be found out.
