So the coronary structure of deoxy hemoglobin is quite constrained. And for this reason, deoxy hemoglobin is said to exist in the t state where t stands for tense. Now, when oxygen begins to bind onto the heme group, it creates this conformational change and it causes this change in the interaction between the surfaces of the different polypeptide chains. And what this does is it lifts that constraint, it relaxes that tertiary, it relaxes that quarterly structure of that hemoglobin molecule. And that's precisely why when all the four heme groups become occupied with oxygen because of the relaxed state of that coronary structure of the hemoglobin, we call this state the r state, where r stands for relaxed. So we see that on the other hand, even though deoxy hemoglobin is quite constrained and exists in the t state, oxymoglobin contains a much more relaxed conformation due to the interactions between the surfaces of the polypeptide chains.