What percentage of carbon dioxide is transported as bicarbonate in the blood?

The correct percentage of carbon dioxide transported as bicarbonate in the blood is approximately 60%. When carbon dioxide is produced in the tissues, it enters red blood cells, where it is converted primarily into bicarbonate (HCO3-) through the action of the enzyme carbonic anhydrase. This conversion is crucial because it helps maintain the acid-base balance in the blood and assists in the transport of carbon dioxide from the tissues to the lungs where it can be exhaled.

The majority of carbon dioxide in the bloodstream exists in this bicarbonate form, which is soluble in plasma and can efficiently travel back to the lungs. The other forms of carbon dioxide transportation include being dissolved in plasma and being bound to hemoglobin; however, these pathways account for a smaller percentage overall. Thus, the fact that around 60% of carbon dioxide is found in bicarbonate form reflects the efficiency of this conversion process and its importance in human physiology.