A major buffer system of human blood relies on carbonic acid (H2CO3) and its conjugate base bicarbonate (HCO3-). The pKa for carbonic acid is 4.77. Use the Henderson-Hasselbalch equation and the pH calculated above to calculate the ratio of [HCO3-] to [H2CO3] in blood (not want the concentrations of each, just the ratio) under normal metabolic conditions. Show your calculation.