The first law of therodynamics state that ae = q - w . is this also a statement of the principle of a conservative of energy ?

The first law of thermodynamics is concerned with the conservation of energy. The key concept in this law is that the change in internal energy is equal to the heat that flows into the system minus the work done. This is the same as saying that if we apply heat to the system, the system may store it as internal energy or use it to perform the work.

chemical digestion occurs in the stomach were hcl and pepsin forms chyme, the mouth in which salivary amylase breaks down starch to form bolus, and the small intestine specifically the duodenum.