HUMAN NUTRITION

Detailed explanation-1: -Physical digestion is the mechanical breakdown of food. Physical digestion in the mouth includes chewing, which masticates, or grinds, food. Chemical digestion in the mouth is done by salivary amylase which is the enzyme in the saliva that breaks down complex carbohydrates into simple sugar.

Detailed explanation-2: -During the process of digestion, the food is broken down into smaller molecules. The salivary glands present in our mouth help in the breakdown of the food. In this process, there is a formation of a new substance. Therefore, it is considered to be a chemical change.

Detailed explanation-3: -Saliva also brings about a chemical change. An enzyme in saliva begins the breakdown of starch into sugars. An enzyme speeds up chemical reactions in your body.

Detailed explanation-4: -Chemical digestion begins in your mouth. As you chew, your salivary glands release saliva into your mouth. The saliva contains digestive enzymes that start off the process of chemical digestion.