Oxygen Dissociation Curve and Bohr Effect
Start with the big picture
Hemoglobin’s sigmoidal oxygen dissociation curve arises from transitions between lower-affinity T and higher-affinity R states. P₅₀ marks the oxygen partial pressure at 50% saturation; a higher P₅₀ indicates lower oxygen affinity and a right shift. Increased CO₂, increased H⁺, higher temperature, and increased 2,3-BPG are among the factors associated with a right shift. In the Bohr effect, CO₂ and H⁺ stabilize the T state, encouraging oxygen release in tissues; in the lungs, the reverse conditions support oxygen loading. The lesson also distinguishes the Bohr effect from the Haldane effect and explores how 2,3-BPG, fetal hemoglobin, stored blood, and high altitude influence the curve.
What you'll learn
- Explain how positive cooperativity produces hemoglobin’s sigmoidal oxygen dissociation curve.
- Interpret P₅₀ and relate right and left shifts to oxygen affinity.
- Describe how CO₂ and H⁺ influence hemoglobin oxygen binding through the Bohr effect.
- Distinguish the Bohr effect from the Haldane effect.
- Identify how 2,3-BPG and selected physiological scenarios modify the curve.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
