Write the procedure involved in the acid and leaf experiment to understand the concept “how the stomach gets protected from its own acid secretions”. Compare the observations with the changes that takes place in human digestive system.
A. 1) Take two similar green leaves.
2) Grease one leaf with petroleum jelly, leave the other free.
3) Add 1 or 2 drops of some weak acids on both the leaves.
4) Observe them after half-an-hour or so and write your observations.
5) The leaf to which petroleum jelly was not applied effected by the acid.
6) We observe the colour of the leaf changes.
7) The other leaf was not affected by the acid because of petroleum jelly.
. From the above activity we can conclude that mucus secreted by the walls of stomach protect it from the harmful effects of hydrochloric acid.