Welcome, students, to the next module of this chapter. Let us go further and learn more about the process of nutrition in human beings.

Beginning with the first part, we all know that the nutrition, that the process of nutrition in human beings takes place in a very special system called as the digestive system. And alimentary canal forms an integral part, forms the main part of the digestive system, and the alimentary canal begins with the mouth. So in other words we can say nutrition in human beings begins with mouth. So let’s find out more about it. Let’s focus on an aspect, dear students, we eat a variety of food items which have to pass through the same digestive track. The food that we eat has a lot of substances in it. And out of these some are hard while some are soft, the hard ones may cause damage to our highly muscular alimentary canal. So then naturally the food has to be first processed to generate particles with small size. Let’s see how does this happen in the mouth.

Okay, now we begin with the process of nutrition in the mouth. We all know we eat food in the form of tiny morsels, in the form of tiny bites. Now the food is taken in through the mouth, okay. Once inside the mouth the food is processed to generate particles with small size. And who helps us to do this, the natural mixers present in our mouth called as the teeth. They do the process of chewing by which the food that we eat is broken down into particles with small size. Furthermore, when the teeth are chewing the food, the salivary glands are stimulated and they secrete saliva into the mouth. The crushed food is wetted with saliva, now what happens because of this. The crushed food is converted into a soft mass that can pass easily through the soft lining of the alimentary canal without damaging it.

So let’s focus once more what all is happening, okay, as we all know, as we can see in the animation behind me, in the image behind me, saliva is completely getting mixed with the food, the food is being completely wetted by the saliva. Okay, once again the food that we eat is in the form of tiny morsels or bites, it is going to be chewed by teeth into particles of smaller size. Simultaneously, saliva is going to be mixed into it, and the food is going to be converted into a soft mass that can easily pass through the lining of the alimentary canal.

Furthermore, dear students, while this process of mechanical digestion that means breaking the food into tiny particles is taking place, one more important event is happening in the mouth. We cannot see it because it is inconspicuous because it is a chemical reaction that is happening. How and who helps us? The saliva contains an enzyme, this enzyme is called as salivary amylase. Focus on the name, dear students, salivary amylase, amylase any enzyme that has ‘ase’ as a suffix is definitely going to break down something in our body. And what is it going to break down? It is going to break down amyl, amyl means starch, amyl means carbohydrates. So, salivary amylase in the saliva acts on one of the major components of the food called as starch. The starch is acted upon by this enzyme and it is broken down into comparatively a simpler substance called as Maltose. Maltose is comparatively a simpler sugar, a disaccharide. Now, so in other words can we say, starch, a complex sugar, present in our food is acted upon by salivary amylase and is broken down into comparatively simple sugar called as maltose in the mouth. Does it tell us that food is partly digested in our mouth? In other words, can you also say the digestion of food starts in the mouth, the process of digestion begins in the mouth.

Dear students, this is a very important give reason for two marks which can come in a paper.

With this information we end this informative module and also the process of digestion.