Under appropriate conditions, hemoglobin dissociates into its four subunits. The isolated α subunit binds oxygen, but the O2 -saturation curve ishyperbolic rather than sigmoid. In addition, the binding of oxygen to the isolated α subunit is not affected by the presence of H+, CO2 , or BPG. What do these observations indicate about the source of the cooperativity in hemoglobin?

Under appropriate conditions, hemoglobin dissociates into its four subunits. The isolated α subunit binds oxygen, but the O2 -saturation curve ishyperbolic rather than sigmoid. In addition, the binding of oxygen to the isolated α subunit is not affected by the presence of H+, CO2 , or BPG. What do these observations indicate about the source of the cooperativity in hemoglobin?

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter11: The Blood

Section: Chapter Questions

Problem 1SQE

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Under appropriate denaturing conditions, hemoglobin can dissociate into four separate subunits. An isolated alpha subunit binds oxygen, but the O2-saturation curve is hyperbolic rather than sigmoid. In addition, the binding of oxygen to an isolated alpha subunit is not affected by the presence of H+, CO2, or BPG. What do these observations indicate about the source of the cooperativity in hemoglobin?
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