Help please will mark

i do not know and i have a 100 in this class

gold i'm pretty sure i might be wrong

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.

where in your body is there an enzyme that does function at a high or low ph? what is the name of that enzyme and its function?