This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
What is the major role of 2, 3 bisphosphoglycerate in RBCs? 
Select and explain. 
A. Acid-base balance, B. Reversal of glycolysis, C. Release of oxygen, D. Binding of oxygen
C: Release of oxygen
Answer: C: Release of oxygen 
Explanation: 2,3 BPG is responsible for significantly lowering the oxygen affinity of hemoglobin and and allowing the hemoglobin to more efficiently release oxygen at the typical Po2 of tissues. Only one molecule of 2,3 BPG interact with each hemoglobin tetramer. Rise in 2,3 BPG in RBCs promotes the shift of hemoglobin to the T form and subsequently release oxygen. In rbcs 2, 3 BPG rise as they adapt to conditions of tissue hypoxia ( from anemia, high altitude, pulmonary dysfunction).