Final answer:
20 percent of carbon dioxide in the blood is bound to the globin part of hemoglobin, forming carbaminohemoglobin, and the process is reversible as represented by the reaction CO2 + Hb → HbCO2.
Step-by-step explanation:
About 20 percent of carbon dioxide is bound to the globin part of hemoglobin, forming a compound known as carbaminohemoglobin. This binding does not occur at the iron ion as it does with oxygen; instead, it happens when carbon dioxide binds to amino acid moieties on the globin portions of hemoglobin. During this process, hemoglobin exhibits a darker maroon color typical of deoxygenated blood. The reversible binding of carbon dioxide by hemoglobin can be portrayed by the chemical reaction CO₂ + Hb → HbCO₂. Carbon dioxide transport in the blood is crucial for respiration as it enables the exchange of gases in the lungs.