Apparatus Two test tubes Water bath at 37°C Starch solution Iodine solution Dropper Source of amylase – a prepared solution of amylase from the laboratory, or rinse mouth with water and spit into a disposable cup.
Method 1. Add 2 cm3
of starch solution to test tubes A and B. A B
Starch and amylase
Starch
Fig. 8 Testing the action of amylase on starch.
2. Add five drops of amylase solution to test tube A. 3. Place the two test tubes into a water bath at 37°C for 15 minutes. 4. Remove the test tubes from the water bath and add five drops of iodine solution to each test tube.
5. Note the colour of the solution in each test tube.
Results Test tube
A Starch + amylase B Starch, no amylase
Questions 1. What colour is iodine in the presence of starch? 2. Why is the experiment carried out at 37o
C?
3. What colour is the solution in test tube A and B after iodine has been added? 4. Explain the results in each test tube.
