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Myoglobin, as a single molecule, has a simple hyperbolic binding curve for oxygen, and has
a P50 value of only 2.8 torr
In contrast, the multi-subunit nature of hemoglobin reduces its affinity at low concentrations
of oxygen and has a much higher P50 value of 26 torr
This increases the dynamic range of hemoglobin, allowing it bind oxygen at high efficiency
in the lungs and unload it with good efficiency in the tissues
This difference in binding is due to the cooperative interactions between the
hemoglobin subunits
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