Karbaminohemoglobin

Karbaminohemoglobin, also known as carbhemoglobin, is a compound formed in the blood when carbon dioxide binds to hemoglobin. This binding is a reversible process and plays a crucial role in the transport of carbon dioxide from the tissues to the lungs for exhalation. Hemoglobin, the protein responsible for oxygen transport in red blood cells, has specific sites where carbon dioxide can attach. When blood passes through tissues where the concentration of carbon dioxide is high due to metabolic activity, carbon dioxide readily binds to these sites on hemoglobin, forming carbaminohemoglobin. This mechanism accounts for a significant portion of the total carbon dioxide transported in the blood, estimated to be around 20-30%.

In the lungs, where the partial pressure of carbon dioxide is lower, the equilibrium shifts, and carbon dioxide is released from hemoglobin. This released carbon dioxide then diffuses into the alveoli to be exhaled. The formation of carbaminohemoglobin is facilitated by the reduced affinity of deoxygenated hemoglobin for oxygen, a phenomenon known as the Haldane effect. This means that as oxygen unloads from hemoglobin in the tissues, hemoglobin becomes more receptive to binding with carbon dioxide. Conversely, in the lungs, as hemoglobin binds with oxygen, its affinity for carbon dioxide decreases, promoting its release. This efficient mechanism ensures the effective removal of metabolic waste products from the body.