THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -Mechanical digestion involves physically breaking down food substances into smaller particles to more efficiently undergo chemical digestion. The role of chemical digestion is to further degrade the molecular structure of the ingested compounds by digestive enzymes into a form that is absorbable into the bloodstream.

Detailed explanation-2: -The stomach lining produces strong digestive juices. These create chemical reactions in the stomach, breaking down and dissolving its nutrients.

Detailed explanation-3: -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-4: -Answer and Explanation: The chemical change that occurs to food in the stomach is that amino acids are released from polypeptides (large proteins). These changes are brought about by the action of proteases or protein digesting enzymes such as pepsin.