Select the correct statements regarding zwitterion.
(i) Zwitterions can be formed from compounds that contain both acid groups and basic groups in their molecules.
(ii) A zwitterion can act either as a proton donor or proton acceptor.
(iii) A monoamine monocarboxylic α-amino acid is a acid at high pH as both the groups (amino and carboxyl) lose a proton.
(iv) Amino acids in solution at neutral pH exist predominantly as dipolar ions, the amino group is protonated
(NH+3) and the carboxyl group is deprotonated
(−COO−).