Demonstrate an experiment to show the action of saliva on food.
Answers
Experiment to show the effect of saliva on starch:
•Two test tubes were taken and were labeled A and B.
•In test tube A one teaspoon full of boiled rice was kept.
•In test tube B one teaspoon full of boiled rice which were chewed for 3-5 minutes were kept.
•3-4 ml of water was added to both the tubes.
•Then 2-3 drops of iodine solution was added to both test tubes A and B.
Observation:
•The test tube A shows blue – black colour whereas test tube B does not show this colour.
Conclusion:
•Since test tube B has boiled rice which were chewed for 3-5 minutes, the saliva present in mouth has acted upon starch to break down into sugars. So it does not show any colour in presence of iodine solution.
•Boiled rice in test tube A has not been exposed to saliva, so starch is present which is indicated by blue-black colour on addition of iodine solution.
Tongue
•Tongue is a fleshy muscular organ which is free at its front end and is attached at the back of the floor of buccal cavity.
•It can move in all directions.
Functions:
•It mixes saliva with food while chewing.
•It plays an important role while talking.
•The taste of the food can be known due to different taste buds present in our tongue.
•It helps in swallowing our food.