Which of the following conditions does not promote the dissociation of 02 from hemoglobin:
High-Yield Explanation
Increasing temperature (e.g., 10, 20, 38, and 43degC) causes reduced binding of O2 by Hgb, reflecting reduced affinity for O2 . In this higher temperature environment, Hgb will more readily release O2 as noted by the right shift of the curves. Increasing pH (e.g., 7.2, 7.4, and 7.6) causes increased binding of O2 by Hgb. As the curve shifts left, Hgb has an increased affinity for O2 . Decreasing pH promote the dissociation of 02 from hemoglobin. 2,3-bisphosphoglycerate (2,3-BPG) (also known as 2,3-diphosphoglycerate) is a small molecule created as a side product of glycolysis from 1,2-BPG. It is present in the same concentration as Hgb in the RBC (2 mM) and is the key molecule in assuring that Hgb does not bind O2 too tightly (ensuring delivery of O2 to the tissues). Ref: Poeus M., Mantanona T. (2012). Chapter 14. Blood. In L.W. Janson, M.E. Tischler (Eds), The Big Picture: Medical Biochemistry.