The pI for amino acids is exactly half-way betwwn the pKa values for the two functional groups. Note that aspartma has the carboxylic acid functionality of phenylalanine. This leaves the aspartic acid amine group and the side chain carboxylic acid functional group of aspartic acid. Find the values for these two groups of as partic acid in table 26.1 and calculate a predicted pI value for aspartame?