Hemoglobin physiologic role

THE OXYGEN DISSOCIATION CURVES FOR MYOGLOBIN HEMOGLOBIN SUIT THEIR PHYSIOLOGIC ROLES... 

Hemoglobin alternates between two structurally and functionally distinct forms to fulfill its physiologic role. 

Probably the most intriguing and important properties of transferrin are those involved in its physiological role as the source of iron for the biosynthesis of hemoglobin by the immature red blood cell. About 30 mg of iron are incorporated into hemoglobin synthesized by the normal adult bone marrow each day, or about 10 times the amount of non-hemoglobin iron in the circulation at any time. Transferrin is the shuttle for this traffic. Since the half-life in serum iron bound to transferrin is 1-2 hr while the half-life of the protein is about 7-8 days (51), the protein must be conserved during its interaction with the immature red cell and re-... 

Implications of oxygen Bohr effect in terms of respiratory quotient and CO2 transport. Its significance for chloride shift and related phenomena. Speculations concerning physiological role of interactions in hemoglobin. 

Sakai, H., Sou, K., Horinouchi, H., Kobayashi, K., and Tsuchida, E. Hemoglobin-vesicle, a cellular artificial oxygen carrier that fulfills the physiological roles of the red blood cell structure. Adv Exp Med Biol 662 433-438, 2010. 

One major consequence of the basicity of imidazole is that at physiological pH (—7.4) substantial quantities of both the free base and protonated imidazole species are present in the histidine units of a protein. This allows histidine to act as either a proton acceptor or a proton donor according to the demands of its immediate environment. It seems likely that histidine units in a number of enzymes such as ribonuclease, aldolase and some proteases may have this role. The buffering action of histidine in the hemoglobin-oxyhemoglobin... 

---