Read of the following passage giving the role of CO_(2) buffer in controlling pH of blood. The importance of pH maintance in Blood. Maintenance of the pH in blood and intracellur fluids is absolutely crucial to the processes the occur in living ogranisms. This is primarily because the functioning of enzymes-catalysts for these processe- is sharply pH dependent. The normal pH value of blood plasma i 7.4. Severe illness or dear can result from subtained variations fo a few tenths of pH unit. Among the factors that lead to a condition of acidosis, in which there is decreas in the pH of blood are heart failure, kidney failure, diabetis mellitus, persistent diarroheoa or a long term high protein diet,temporary condition acidosis may result from proglonged, intensive in ph of blood, may several factors are involved in the control of the pH of blood. A particularly important one is the ratio of dissolved,OH_(3)^(-) to H_(2)CO_(3).CO_(2)(g) is moderarately soluble in water and in aqeous solution reactns only a limilated extent to product H_(2)CrO_(3) CO_(2) + H_(2)O hArr H_(2)CO_(3(aq)) H_(2)CO_(3) + H_(2)O hArr HCO_(3)^(-) + H_(3)O^(+) , pK_(al) = 6.11 HCO_(3)^(-) + H_(2)O hArr CO_(3)^(2-) + H_(3)O^(+), pK_(a2) = 10.25 In the H_(2)CO_(3), HCO_(3)^(-) buffer system we deal only with the first ionisation step (K_(al)) H_(2)CO_(3) is a wear acid and HCO_(3)^(-) is the conjugate base (salt). CO_(2) enters the blood from issues as the by product metabolic reaction. In lungs, CO_(2)(g) is exchanged for O_(2)(g), which is transported throughout the body the blood. The pH of blood system is maintained by a proper balance of H_(2)CO_(3) and NaHCO_(2) concentration. The volume of 5M NaHCO_(3) solution should be mixed with a 10 m sample of blood which is 2M in H_(2)CO_(3) order to maitain its pH