2. 2,3-bisphosphoglycerate is an allosteric inhibitor of oxygen binding to hemoglobin. a. Acclimatization to high altitude involves numerous physiological and biochemical changes, including an increase in the concentration of 2,3-bisphosphoglycerate in red blood cells. Explain why the 2,3 bisphosphoglycerate concentration increases at high altitude. b. The 2,3-bisphosphoglycerate concentration in maternal red blood cells also increases during pregnancy. Why