Explain how CO[sub]2[/sub] is buffered in the blood causing stabilization of blood Ph.
CO2 itself is an inert substance and does not change pH. However, in blood, CO2 reacts with water and forms carbonic acid (H2CO3). This acid dissociates (to H+ and HCO3-) and can lower blood pH, but there are 4 buffering systems, that work simultaneously and prevent blood pH from changing. The systems are called bicarbonate, phosphate, haemoglobin and protein buffering systems. This systems have acceptors of protons (such as COO- groups of proteins and haemoglobin, HCO3- and (NaHPO4)2- ions) which react with proton that is created when CO2 dissolves in blood, so the proton is neutralized. Thus, the amount of protons is stable and blood pH does not change.