It is beyond the scope of this class to understand the following. If only one equilibration is in effect, the pH of the solution is determined by one Henderson-Hasselbalch equation
1. Living matter is composed mostly of the lighter elements 1.1 The composition of living matter is strikingly different from that of its physical environment(1810s) 1.2 The elements found in living organisms also exist in nature(especially in seawater and atmosphere)