What happens to affinity with a shift to the right on the Hemoglobin dissociation curve?

What happens to affinity with a shift to the right on the Hemoglobin dissociation curve?

• A. Increase affinity
• B. No change
• C. Decrease affinity
• D. Saturation increases

Answer: (C)

A shift to the right on the oxygen-hemoglobin dissociation curve means hemoglobin has a lower affinity for oxygen. At the same partial pressure of oxygen, hemoglobin saturates less, and it releases oxygen more readily to tissues. This occurs with factors such as higher CO2, lower pH (more acidic), higher temperature, and increased 2,3-BPG—collectively described by the Bohr effect. In tissues with high metabolic activity, these conditions promote more efficient oxygen unloading where it’s needed. Conversely, a leftward shift increases affinity, making oxygen binding tighter and unloading harder.

A shift to the right on the oxygen-hemoglobin dissociation curve means hemoglobin has a lower affinity for oxygen. At the same partial pressure of oxygen, hemoglobin saturates less, and it releases oxygen more readily to tissues. This occurs with factors such as higher CO2, lower pH (more acidic), higher temperature, and increased 2,3-BPG—collectively described by the Bohr effect. In tissues with high metabolic activity, these conditions promote more efficient oxygen unloading where it’s needed. Conversely, a leftward shift increases affinity, making oxygen binding tighter and unloading harder.