Question

1. What is the P₅₀? What does it mean if the P₅₀ is lowered? Raised?

I dont really understand how a lowering P50 decreases oxygen binding in hemoglobin (and visversa), could you please explain. Thankyou

Answer 1

The P50 can be considered as the oxygen tension at which hemoglobin is 50% saturated and the normal P50 is around 26.5 mm of Hg.

Increase in P50 gets to lower the hemoglobin’s affinity for oxygen and this can get to displace oxygen from hemoglobin and release it to the tissues.

Decrease in P50 gets to increase hemoglobin’s affinity for oxygen, thus reduces the availability of the oxygen to the tissue.

In biochemistry, P₅₀ indicates the partial pressure of a gas that is required to achieve 50% enzyme saturation and when the value decreases it allows more oxygen to come in as the affinity actually increases.