Which amino acid would have its isoelectric point near pH 10?

Question

Quizplus · Accepted Answer

The isoelectric point is the pH at which a molecule has a net charge of zero. For lysine, the side chain contains an amino group with a pKa of approximately 10.8, so at a pH near 10 the amino group would be mostly protonated (+1 charge) while the carboxyl group would be mostly deprotonated (-1 charge). As a result, the net charge on lysine would be close to zero, indicating that its isoelectric point is near pH 10.

Which Amino Acid Would Have Its Isoelectric Point near PH