How contaminated food enters the stomach, it avoids breakdown by digestion. Exactly how and why does that
happen? also hormones that are released by the stomach.
Please explain how they are involved. can you please
someone help me for this question

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

digestion

it excretes wastes