Introduction to Biochemistry - Quiz 3.2.2

In the R state, hemoglobin has a higher affinity for oxygen, while in the T state, hemoglobin has a lower affinity for oxygen.

The answers are 15 and 60, this is just reading curves. Note that the question ask for the "release" of it, so it is 100 minus the read value.

Curve A has a higher affinity, Curve B has a lower affinity.
Lung has higher affinity, vein has lower affinity.
Presence of 2,3 BPG has a lower affinity.

Therefore the answer is:

Curve A represents oxygen binding in the lung, while curve B represents oxygen binding in the veins.

The easy way to remember this is lung blows out carbon dioxide, drive the carbonic acid to disassociate, driving up the pH - and at the lungs, we have higher affinity.

The curve labeled curve A likely represents hemoglobin binding at a higher pH, and the affinity for oxygen is higher than hemoglobin's affinity for oxygen at pH 7.4.

The curve labeled curve B likely represents hemoglobin binding at a lower pH, and the affinity for oxygen is lower than hemoglobin's affinity for oxygen at pH 7.4.

• Lactic acid decrease the affinity of hemoglobin for oxygen. (Because of reduced pH)
  
• Carbon dioxide decrease the affinity of hemoglobin for oxygen (Because additional carbon dioxide drives the formation of carbonic acid, driving down pH)
  
• 2, 3 bisphosphoglycerate decrease the affinity of hemoglobin for oxygen (Because 2,3 BPG occupies the binding site with hydrogen bond and salt bridges, making T state more stable)

The behavior allows for relatively large change in oxygen delivery by relatively little change in oxygen partial pressure. That in turns make it possible to reach homeostasis faster.