zwitterion

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ion

 [i´on]
an atom or group of atoms having a positive (cation) or negative (anion) electric charge by virtue of having gained or lost an electron; substances forming ions are called electrolytes. adj., adj ion´ic.
dipolar ion an ion that has both positive and negative regions of charge.
hydrogen ion the positively charged hydrogen atom (H+), which is the positive ion of all acids. See also hydrogen ion concentration.
hydroxyl ion the negatively charged group, OH, present to excess in alkaline solutions.

zwitterion

/zwit·ter·ion/ (tsvit´er-i″on) an ion that has both positive and negative regions of charge.

zwitterion

[tsvit′ərī′ən]
a molecule that has regions of both negative and positive charge. Amino acids such as glycine are almost always present as zwitterions when in neutral solutions. Also called dipolar ion.
Zwitterionclick for a larger image
Fig. 318 Zwitterion . Molecular structure of (a) undissociated amino acid, (b) Zwitterion.

zwitterion

the chemical form of an AMINO ACID with a dipolar ion state. The pH at which the amino acid exists as a zwitterion is called its ISOELECTRIC POINT and at this pH it will not migrate in an electric field, produced, for example, by ELECTROPHORESIS.

zwitterion

an ion that has both positive and negative regions of charge. Called also dipolar ion.