Carbonic Anhydrase's Role in CO2 Transport and Bohr Effect

Steps:

• Carbonic anhydrase (CA) catalyzes CO2 + H2O → H2CO3 → H+ + HCO3- in red blood cells.
• Reduced CA slows H+ production from CO2 hydration.
• Lower H+ reduces blood acidification in tissues.
• Decreased H+ impairs Bohr effect, limiting oxyhemoglobin dissociation.

Why B is correct:

• Bohr effect states H+ lowers oxyhemoglobin's O2 affinity; reduced CA limits H+, so less O2 unloads to active tissues.

Why the others are wrong:

• A: Carbaminohemoglobin forms via direct CO2-Hb binding, independent of CA.
• C: Reduced CA decreases H+ formation, raising pH (alkalosis), not lowering it.
• D: Reduced CA slows carbonic acid dissociation, not increases it.

Final answer: B