Which could be a reason viruses are considered nonliving things?

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?