A molecule that has >1 localized charges which may be of opposite polarity. That is to say, it may be a positive ion on one side, and a negative ion on the other.
Most free amino acids form zwitterions, and in this way the negative and positive ends join together to form a chain. When these chains reach a length of thousands of links they become proteins.
a chemical atom thing...named by some german scientist who obviously had some probs cause...well, see zwitter
me: u kno what's a funny word? zwitter
other person: ooooooh like zwitterion!