NIOS Class 10 Science Activity 22.2 Life Processes Solution

This activity shows how digestion of carbohydrates begins in the mouth. In activity 22.1, we have discussed essential nutrients required for a balanced diet.

 

Life Processes Activity Solution

This activity is based on the NIOS Class 10 science and technology (212) Chapter 22- Life Processes Module 5- The Living World.

Aim

To observe the change in taste of bread/chapati during chewing and understand the role of saliva in digestion.

Materials Required

    1.  Small piece of bread/chapati

Procedure

We take a small piece of bread or chapati and bite it, and note the initial taste.

Now we chew it well with our teeth and roll it with the tongue for some time, and observe the taste.

Observation

We find –

   1. Initial taste- Tasteless

   2. After chewing- sweet taste

Explanation

Bread or chapati contains starch. When we chew it, saliva in the mouth contains an enzyme called salivary amylase(ptyalin).

This enzyme converts starch into simple sugars(maltose), so due to the formation of sugar, the taste becomes sweet after chewing.

Conclusion

This activity explains that the digestion of carbohydrates starts in the mouth with the help of saliva. So proper chewing helps in better digestion of food.