In order to live, we must have a constant supply of oxygen to our cells. We get this oxygen by breathing in air. The oxygen in the air mixes with blood and becomes bound by hemoglobin. The oxygenated hemoglobin then transports the oxygen to cells that need it. Once there, the hemoglobin releases oxygen. Excess carbon dioxide is picked up by the hemoglobin and transported to the lungs where it is released and exhaled.
Using the concepts of equilibrium and Le Chatelier's principle, explain why oxygen moves from the air in the lungs to cells and carbon dioxide moves from cells to the air in the lungs.