MCB 2000 Lecture Notes - Lecture 5: Partial Pressure, Hemoglobin, Myoglobin
10 Sep 2019
School
Department
Course
Professor
Document Summary
The oxygen bound subunit will then change shape, which causes conformational changes with the neighboring subunits. In low oxygen conditions, after hemoglobin has given up its oxygen molecules, not only does it change conformation to a lower oxygen affinity state but it also encounters fewer free oxygen molecules to refill its empty binding sites. In addition, a molecule in red blood cells called 2,3. Bpg fits into a pocket in the t state and will stabilize this deoxygenated form of hemoglobin. In the lungs, hb becomes nearly saturated with oxygen, such that 98% of the binding sites are occupied. In the tissues, the saturation level drops to 32: the difference, 66%, reflects the proportion of oxygen binding sites. Imagine mb is replacing hb in red blood cells performing the task of oxygen transport. If mb were exposed to the partial pressure of oxygen in the lungs, it would be. 98% saturated: however, in the tissues, mb is still 91% saturated!
