To study about the action of salivary amylase on starch
Answers
All enzymes are basically types of proteins. Salivary amylase is deactivated at a lowe temperature while at a higher temperature, it is denatured.
Therefore, at higher and lower temperatures, more time will be taken by salivary amylase to digest starch.
A temperature of 37 degrees Celsius can be considered to be the ideal as salivary amylase is most active then and takes the least time to digest starch.
Moreover, at a pH of 6.8, salivary amylase can digest starch optimally showing that it is neither acidic or alkaline.
To collect the sample, rinse your mouth with a little water and wait 5 minutes before beginning to collect saliva in the tube. During the collection, do not cough, clear your throat or collect mucous from the back of your throat into the collection tube. Allow saliva to accumulate naturally in your mouth, and when an adequate amount is collected, transfer this to the saliva collection tube.
Experiment
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.