This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'As blood passes through the tissues, all of the following actions occur EXCEPT that \nSelect and explain. \nA. Bicarbonate concentration of blood decreases, B. The affinity of hemoglobin for 02 decreases, C. The ability of hemoglobin to bind C02 increases, D. The ability of hemoglobin to bind H increases', 'role': 'user'}, {'content': 'Answer: A \nExplanation: CO2 is formed in the tissues and diffuses into the blood. A small fraction dissolves in plasma, where it exes a paial pressure. The remainder diffuses into the red blood cell, where it can either bind directly to the free NH2 groups on hemoglobin (a carbamino compound) or become hydrated in the presence of the enzyme, carbonic anhydrase, to form carbonic acid. This acid is in equilibrium with its dissociated form of H+- and HCO3- .', 'role': 'assistant'}]