carbhemoglobin
Carbhemoglobin is a compound formed when carbon dioxide binds to hemoglobin, the protein in red blood cells responsible for oxygen transport. This binding is a reversible process that plays a crucial role in the transport of carbon dioxide from the body's tissues to the lungs for exhalation. When carbon dioxide is produced during cellular respiration, it diffuses into the bloodstream. A small portion of this carbon dioxide directly binds to the amino groups on hemoglobin molecules, forming carbhemoglobin. This reaction is distinct from the binding of oxygen to hemoglobin, which occurs at a different site on the molecule. The formation of carbhemoglobin helps to buffer the blood, as it can also facilitate the release of hydrogen ions. In the lungs, where carbon dioxide concentration is lower, the equilibrium shifts, and carbon dioxide is released from hemoglobin to be exhaled. The amount of carbon dioxide transported as carbhemoglobin varies depending on factors such as blood pH and oxygen saturation levels. While oxygen transport is the primary function of hemoglobin, its role in carbon dioxide transport through the formation of carbhemoglobin is also vital for maintaining physiological homeostasis.