Which statement describes CO2 transport in blood?

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Multiple Choice

Which statement describes CO2 transport in blood?

The main idea is how CO2 travels in the blood: the majority is carried as bicarbonate ions in plasma. CO2 produced by tissues diffuses into red blood cells, where carbonic anhydrase converts it with water into carbonic acid, which quickly dissociates to bicarbonate (HCO3−) and hydrogen ions. The bicarbonate then exits the red blood cells into the plasma in exchange for chloride (the chloride shift), so most CO2 is effectively transported as dissolved bicarbonate in the plasma. The remaining CO2 is carried as dissolved gas in plasma and as carbaminohemoglobin bound to proteins, but these forms are minority compared with bicarbonate. That’s why the statement about bicarbonate ions in plasma being the primary transport form best fits how CO2 is carried in blood.

The main idea is how CO2 travels in the blood: the majority is carried as bicarbonate ions in plasma. CO2 produced by tissues diffuses into red blood cells, where carbonic anhydrase converts it with water into carbonic acid, which quickly dissociates to bicarbonate (HCO3−) and hydrogen ions. The bicarbonate then exits the red blood cells into the plasma in exchange for chloride (the chloride shift), so most CO2 is effectively transported as dissolved bicarbonate in the plasma. The remaining CO2 is carried as dissolved gas in plasma and as carbaminohemoglobin bound to proteins, but these forms are minority compared with bicarbonate. That’s why the statement about bicarbonate ions in plasma being the primary transport form best fits how CO2 is carried in blood.

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