Bicarbonate moves out of RBC in peripheral tissues in exchange for
Na+
HP02 4-
Cl-
S02 4-
Unlike carbon dioxide, bicarbonate is very soluble in the blood plasma and therefore must return thereby moving out of the red blood cell. However, as it moves across the membrane, a chloride ion is brought into the cell. This is known as the chloride shift and it takes place in order to maintain electric neutrality. Ref : Biochemistry by U. Satyanarayana 3rd edition Pgno : 197-200
Metabolism of protein and amino acid