Effect of pH on the rate of activity of amylase enzyme
1. On a tile, label each well with the time (from 0 onwards) and add a drop of iodine solution to each well
2. Add 2 cm3 of each buffer solution using a syringe (ranging from pH 3.0 to 7.0) into each labelled test tube
3. Immerse the starch solution, amylase solution, and the test tubes of buffer solution in a water bath at 25°C
4. Allow a few minutes for the temperature to equilibrate
5. Use a syringe to add 2 cm3 of amylase into a test tube of buffer solution
6. Use a syringe to add 2 cm3 of starch into the same test tube and start timing immediately
7. Use the glass rod to transfer a drop of the mixture to the well labelled '0' on the tile
8. Repeat step 6 every 30 seconds, rinsing the glass rod in between every test, until the iodine solution remains brown and does not turn blue-black
9. Calculate the rate of enzyme reaction by using 1/ time taken for iodine solution to remain brown
10. 10. Repeat steps 2-8 for buffer solutions with different pH values
11. 11. Plot a graph of the rate of enzyme reaction against pH
