Question

Starch digestion begins in
A. Small intestine
B. Large intestine
C. Stomach
D. Esophagus
E. Mouth

Answer 1

Hint: Digestion is a process in which various compounds present in the food are converted into micro molecules form macromolecules. These macromolecules are then absorbed by our body cells for overall growth of our body. This conversion of molecular compounds of food in our body is termed as digestion.

Complete answer:
There are several molecules present in our food like starch, lipids, proteins, carbohydrates and nucleic acids. These are termed as macromolecules in our food which are not consumable by our body cells as they need to be converted into micro molecules. These macromolecules can be consumed by our body cells to generate nourishment for overall functioning of our body. Different macromolecules are converted by different parts of our body through a process. This process begins with intake of food into our mouth as this food moves through our GI tract.

In-mouth chewing begins with mixing of food with saliva released by our salivary glands which helps in breakdown of starch present in our food. Tongue pushes the chewed food into our throat as there is a flap of tissue, named epiglottis helps to close our windpipe so that food moves into esophagus.

From the esophagus, a process called peristalsis starts and passes food to the lower esophageal sphincter as it relaxes and sends the food to the stomach. In the stomach various digestive juices are present which break down the food molecules further. This food is now converted into chyme as it is mixed with digestive juices and passes to the small intestine.

In small intestine food is mixed juices secreted by liver, pancreas and intestine which help in further breakdown of fats, carbohydrates and proteins. Small intestine helps in passing water and nutrients into your bloodstream as its wall helps in absorption of these molecules. Undigested food from the small intestine passes into the large intestine and water is absorbed here and remaining is converted into stool which is emitted by rectum.

Hence, The correct answer is, option (E).

Note: Digestion in mouth is done physically as we need to chew the food after intake in our mouth but when food passes to the esophagus the digestion process becomes automatic and different parts of the body play different and unique roles in the digestion process.