An Octapeptide Composed of Four Repeating Glycylalanyl Units Has

Multiple Choice

An octapeptide composed of four repeating glycylalanyl units has:

A) one free amino group on an alanyl residue.
B) one free amino group on an alanyl residue and one free carboxyl group on a glycyl residue.
C) one free amino group on a glycyl residue and one free carboxyl group on an alanyl residue.
D) two free amino and two free carboxyl groups.
E) two free carboxyl groups, both on glycyl residues.