In which part of the digestive system does a chemical change of the food first occur? mouth esophagus stomach liver

The answer is: the mouth.

Explanation:

Chemical digestion is the breakdown of food into small particles to subsequently go through the process of absorption and transport to cells.

The mouth secretes enzymes capable of breaking relatively strong intra-molecular bonds so that difficult-to-digest molecules turn into small, digestible molecules (Nutrients).

1. what is the relationship between the shape of an enzyme and the reactions they catalyze?

2. how does an enzyme inhibitor work?

separate your answers so i dont get confused : )