Derive the henders on- hasselbalch equation for the acid ioniza tion of a weak acid ha and use this equation to construct a concentration ph profile for the essential amino acid phenyla lanine, the structure of which is given below. the following are relevant pka and pi values: pkaj 2.58; pka 9.24; pi 5.48. in all cases clearly identify and label the structures involved in each acid ioniza tion step. (12 ma versus