Take 6 clean and dry test tubes. Pipette out 0.5 mL of enzyme to each, except
for the first tube, which serves as a blank. Add 0.5 mL of substrate to each tube.
Incubate each for 20 minutes at respective temperatures (13°C, 25°C, 36°C, 50°C,
and 60°C). Add 1 mL of DNS reagent to each test tube and keep all test tubes
in a boiling water bath for exactly 5 minutes. Add 10 mL of distilled water to
each tube and read the OD at 540 nm.
Plot the graph by taking temperature on the x-axis and activity on the y-axis.
Result: The optimum temperature of the human salivary a-amylases is 36°C.