Important buffer in the extracellular fluid is:

Ans. C. BicarbonateThe bicarbonate buffer system is the most important extracellular buffer. Although it has a relatively low buffering capacity with pKa 6.3, it plays an important role in maintaining blood pH because1. Of its high concentration 2. The two elements, HCO3- and CO2 of H2CO3 are regulated by increasing or decreasing the rate of reabsorption of HCO3- by the kidneys and by altering the rates of removal or retention of CO2.