ACID – BASE BALANCE
بسم الله الرحمن الرحيم Acid is a proton donor while base is proton acceptor: H2O H+ + OH¯ From the equation, water can act both as an acid & as a base, for dissociation: ]O2H[]-][OH[H K It has been found that 1 mol of water contains 18 g, i.e. 1 L (1000 g) pure water is 55.56 molar. The probability that a H in pure water will exist as an H+ is 1.8 X 10-9, so the molar conc. of H+ or OH¯ in pure water = 55.56 X 1.8 X 10-9 = 1X10-7 mol/l mol/l 16-10 X 1.8 ]56.55[]-][OH[H K Kw = K [H2O] = [H+][OH¯] 1.8 X10-16 X 55.56 = 1 X 10-14 (mol/l)2 [H+] = [OH¯] = 1 X 10-7 (mol/l) PH = – log [H+] PH = – log 10-7 = – (–7) = 7 PH + POH=14 Physiologic processes that generate H+ 1- Complete metabolism i- CHO, proteins & fats ii- Conversion of amino nitrogen to urea NH3 from NH4 & NH3 from asparate urea + 2 H+ iii- Conversion of sulphur of SH containing AAs to sulphate Cysteine metabolism, 2 H+ + SO