ɐspˈɑːɹɾɪk ˈæsɪd, fɔːɹ ɛɡzˈæmpəl, pəzˈɛsᵻz wˈʌn pɹˈoʊtənˌeɪɾᵻd ˈæmaɪn ænd tˈuː dᵻpɹˈoʊtənˌeɪɾᵻd kˈɑːɹbəksˌɪl ɡɹˈuːps, fɚɹə nˈɛt tʃˈɑːɹdʒ ʌv mˈaɪnəs wˈʌn æt fˌɪzɪəlˈɑːdʒɪkəl pˈiː ˈeɪtʃ.
Aspartic acid, for example, possesses one protonated amine and two deprotonated carboxyl groups, for a net charge of −1 at physiological pH.