Britannica
Sources used in this answer
How does hemoglobin release oxygen in body tissues?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
human respiratory system
The lungs serve as the gas-exchanging organ for the process of respiration.
Hemoglobin releases oxygen in body tissues primarily through a process driven by the partial pressure of oxygen and the chemical environment of the blood.12
In tissues where oxygen tension is relatively low, the partial pressure gradient encourages oxygen to dissociate from hemoglobin and diffuse into the cells. This release is further regulated by several factors that decrease hemoglobin's affinity for oxygen, shifting the oxygen-dissociation curve to the right:12
- The Bohr Effect: As tissues metabolize, they produce carbon dioxide and hydrogen ions, which increase acidity (lower pH). These substances bind to hemoglobin, altering its structure and reducing its ability to hold onto oxygen.12
- 2,3-Diphosphoglycerate (2,3-DPG): This salt, produced by red blood cells, also binds to hemoglobin and decreases its oxygen affinity, facilitating oxygen delivery.12
- Temperature: Increased metabolic activity in tissues can raise local temperatures, which similarly shifts the curve to favor oxygen release.1
These mechanisms ensure that oxygen is efficiently delivered to tissues based on their specific metabolic demands.1