The Bohr effect and the Haldane effect in human hemoglobin.

Area of Science:

• Physiology
• Biochemistry
• Respiratory System

Background:

• Hemoglobin's oxygen affinity is modulated by physiological regulators like protons and carbon dioxide.
• The Bohr effect describes the heterotropic allosteric interaction between non-heme ligands and oxygen.
• This interaction is vital for efficient oxygen transport and carbon dioxide exchange in the blood.

Purpose of the Study:

• To thermodynamically formulate and explicitly define Bohr and Haldane coefficients.
• To clarify the use of the term "Bohr effect" in scientific literature.
• To outline the molecular mechanism and physiological significance of the classical Bohr and Haldane effects.

Main Methods:

• Thermodynamic formulation of heterotropic allosteric interactions.
• Definition of Bohr and Haldane coefficients.
• Analysis of molecular mechanisms and physiological roles.

Main Results:

• Explicit definitions of Bohr and Haldane coefficients are provided, distinguishing classical coefficients.
• Thermodynamic formulations clarify the interactions between ligands and oxygen.
• The Haldane effect appears to have a greater physiological role than the Bohr effect in carbon dioxide transport.

Conclusions:

• Clear definitions of Bohr and Haldane coefficients reduce ambiguity in literature.
• The Bohr effect's thermodynamic basis and physiological significance are elucidated.
• The Haldane effect plays a more substantial role in physiological gas exchange than previously emphasized.