What experiment do you perform to understand action of saliva on flour? Explain it’s procedure and apparatus that you followed.
A. Experiment to understand action of saliva on flour.
Aim : To demonstrate the action of saliva on flour.
Apparatus : Test tubes (2), flour, watch glass, dilute tincture iodine, saliva (1 teaspoonful)
Procedure:
- Take a test tube half-filled with water and add a pinch of flour to it.
- Shake the test tube well till the flour gets mixed.
- Take a few drops of this mixture in a watch glass and test for the presence of starch by putting a drop of dilute tincture iodine in it.
- A blue-black colour confirms the presence of starch.
- Now again dissolve a pinch of flour into half-filled water in a test tube.
- Now divide the mixture into two equal halves by transferring it to another test tube.
- Note that both the test tubes have the same amount of solution.
- Add a teaspoon of saliva to one of the test tube and mark it.
- Do not add anything in the other test tube.
- After sometime (45 minutes) add a drop of dilute tincture iodine solution to test tubes containing the solution.
Observation : - The solution of the test tube to which saliva is added shows colour change as starch is converted to sugar.
- There is no colour change in the other test tube to which saliva is not added. Inference
result:
The enzyme amylase in the saliva breaks down the starch molecules into smaller subunits usually into sugars.