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Biochemistry

Metabolism and Other Biochemical Reactions

How is O2 transported through the body?

Oxygen enters our body through our lungs in the air we breathe. O2 makes up about 21% of the total volume of air on Earth. From the lungs, O2 diffuses into the bloodstream, where it binds to a molecule called hemoglobin in our red blood cells. The binding affinity of O2 to hemoglobin is pH-dependent such that oxygen can readily be picked up by red blood cells near the lungs and then released into tissues and other areas of the body that need it.