Hemoglobin relaxed high affinity form

Uptake of 02 is associated with substantial conformational changes, which are central to an understanding of the cooperative efEect. These conformational changes are associated with the reversible interconversion of a tensed (T), low affinity form of hemoglobin into a relaxed (R) high affinity form. 

Hemoglobin can exist in two forms. The deoxy form of Hb is called the taut (T) form, and the oxygenated form of Hb is called the relaxed (R) form. The Rform is the high oxygen-affinity form of hemoglobin. 

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