[HongKongALevelboy]

the definition of zwitterion is not clearly stated in my book . Can anyone definite ' zwitterion ' ? i want a concise answer . thx ^_^

[movies]

A zwitterion is a molecule with a positive charge on one atom and a negative charge on another atom.  The most common example is probably in amino acids, which exists with the acid deprotonated and the amine protonated.  It's derived from the German zwei, meaning two ("two ions").

[Donaldson Tan]

must the overall charge of a zwitterion be zero? eg. in the case of aminoacids, what if the molecule contain 2 -NH₂ and 1 -COOH group..

[movies]

Yes, I just double checked in my chemical dictionary and it says that it's a positive and a negative charge.

[AWK]

Zwitterion is a specific name for net not charged molecule, so theoretically molecule may possess two positive and two negative charges.

[Donaldson Tan]

so a zwitterion is an ion that contains at least a pair of oppositely-charged sites, such that its overall charge is zero..

[AWK]

Any proposition for double zwitterionic amino acid (natural, but non-protein one)?