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Isoelectric points quick question

The isoelectric point of glutamic acid is at pH=3.22. Write the formula of ionic species of glutamic acid present at pH=1 So would it be HOOCCH2CH2CH(NH4+)COOH or HOOCCH2CH2CH(NH3+)COOH. The zwitterion has 2+charge on the amino group which is true when ascribed to the definition. For pH lower than iso point it behaves as basic and has "+" overall charge the definition says doesn't say whether the no of COOH effects. NH3^+ and NH4^2+ both make it charged positively overall how'd you know which one's right?