Experiments
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To investigate the effect of pH on the rate of enzyme activity
1. Perform experiment 1 at different pH values. This is done by adding a few drops of HCl to make the substrate solution more acidic. Add a few drops of NaOH to make the solution more basic. Use a buffer in each to maintain the pH. The pH can be checked using universal indicator. A control must be set up for each pH.2. Keep temperature constant by using a water bath set at 37oC.
3. Keep substrate concentration constant by using the same volume of the same starch solution each time.
4. Keep enzyme concentration constant by using the same volume of the same amylase solution each time.
5. Every minute remove a sample from each test tube and test with Iodine.
6. Record the time taken for the disappearance of the starch i.e. the time taken to get a yellow-brown.
7. Rate = 1/Time. The longer the time the slower the rate.
8. Graph the results with pH on the x-axis.
