The diagram below shows a cross-section through an alveolus and a capillary. Why does oxygen move from P to Q?

Diagram pleasss

Explanation:

The layers of cells lining the alveoli and the surrounding capillaries are each only one cell thick, so the exchange surfaces are very thin, and they are in close contact with each other. Oxygen therefore diffuses quickly through the alveolar walls and into the capillaries.

Explanation:

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?