Question

Action of saliva on wheat flour?

Answer 1

The enzyme salivary amylase in the saliva breaks down the large starch molecules into smaller subunits which is usually into sugar.

Answer 2

Aim: to show the action of saliva on wheat flour.

Apparatus: test tube, wheat flour, iodine, watch glass, dropper 

Procedure:
1. Take a test tube and fill it with water and a spoonful of wheat to it and stir it well.
2. Take around 4-5 drops of this solution in to the watch glass and with the help of a dropper add a drop of the diluted iodine to the solution.
3. Leave the test tube for around 5-10 minutes and observe the test tube.
4. Now take 2 more test tubes and pour equal amount of the water in the test tube and add spoonful of wheat flour to each of the test tube.
5. In one of these test tubes add around 2 spoons of saliva (before taking saliva on to the spoon see through that you'll wash you mouth with water)
6. After around 45 minutes or 60 minutes add iodine to both of the test tube and observe it carefully.

Observation:
1. In the 1st test tube where there was only water, flour when the iodine solution was added the color of the solution turned blue-black due to the presence of the carbohydrates in the solution.
2. In the 2nd test tube where there was only water, flour, saliva when the iodine solution was added the color of the solution didn't turn blue-black due to the action of the saliva.
3. As same as the 1st test tube the 3rd test tube also turned to blue-black

Inference: The enzyme salivary amylase which is present in the saliva will convert more overly they'll break down the large starch molecules into the smaller forms of sugars. This action was taken place in the 2nd test tube where saliva was added so the color of the solution didn't change to blue-black as it changed in the 1st and 3rd test tube.