Starting with an aqueous solution of fully deprotonated isoleucine (draw the structure of this form of isoleucine!), would you need to add strong acid or strong base to fully protonate the amino acid (draw the structure of this form of isoleucine!)? How many equivalents of strong acid/base would you need until half of isoleucine's a-carboxyl groups have been protonated? Explain and draw the structure of this form of isoleucine! What is the protonation state of the a-amino group at this point?