Question

Where do the oxygen molecules that our cells need come from? Be specific. How do they enter the body and if they don’t enter as oxygen, how do they become oxygen?

Answer 1

Answer:

The oxygen molecules move, by diffusion, out of the capillaries and into the body cells. While oxygen moves from the capillaries and into body cells, carbon dioxide moves from the cells into the capillaries. Carbon dioxide is brought, through the blood, back to the heart and then to the lungs.

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