Zwitterion

A zwitterion is a molecule that has both positive and negative charges, but overall remains electrically neutral. Think of it like a molecule with one end carrying a slight positive charge and the other end a slight negative charge. This dual charge distribution allows zwitterions to interact uniquely in biological systems, especially amino acids—the building blocks of proteins—where the amino group can carry a positive charge and the carboxyl group a negative charge. The presence of both charges in a single molecule plays a key role in processes like solubility, structural stability, and chemical reactivity in aqueous environments.