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Related to zwitterion: isoelectric point


 (zwĭt′ər-ī′ən, swĭt′-, tsvĭt′-)
A molecule, especially an amino acid, containing a positively charged ion at one end and a negatively charged ion at the other.

[German : Zwitter, hybrid (from Middle High German zwitarn, from Old High German, from zwi-, twice; see dwo- in Indo-European roots) + Ion, ion (from Greek; see ion).]

zwit′ter·i·on′ic (-ī-ŏn′ĭk) adj.


(Chemistry) chem an ion that carries both a positive and a negative charge
[C20: from German Zwitter hermaphrodite + ion]
zwitterionic adj


(ˈzwɪt ərˌaɪ ən, ˈswɪt-, ˈtsvɪt-)

an ion with both a positive and a negative charge.
[< German Zwitterion (1897) =Zwitter hybrid, hermaphrodite + Ion ion]
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References in periodicals archive ?
These functional groups can exist as cation, zwitterion or anion species, depending on the pH of the solution [3].
It exists as zwitterion in the pH conditions of small intestine.
Hydroperoxide 21 is also a known product of the singlet oxygen-mediated oxidation of tryptophan, and it gets converted via its hydroperoxide isomer 22, zwitterion 23, and dioxetane 24 to N-formylkynurenine 25 [34, 55].
The results of previous works reveal that the zwitterion mechanism developed by Caplow [21] and Danckwerts [22] is acceptable for this reaction [11]:
For clays modified with zwitterion, nonionic and anionic surfactants (TMG, HEC, TRITON X-100, LABSA and SLES), it was seen that the liquid limit and plasticity index increased when surfactant percentage was increased.
First step is a 1,3 dipolar cycloaddition of ozone to the olefin leading to the malozonide (1) (Criegee intermediate), which is very unstable and decomposes to give a zwitterion (2) and a carbonyl compound (3) In the presence of reactive solvent, such as water or alcohol, the zwitterion interact with the solvent to give hydroperoxides (4) in high yield, since the concentration of the solvent far exceeds that of any other substances with which the zwitterion may react.
The molecule tends to exist as a zwitterion where a phosphonic hydrogen dissociates and joins the amine group.
The newly developed liquid crystals contain a zwitterion made up of a negatively charged inorganic portion and a positively charged organic portion.
In vitro evaluation of zwitterion buffers in diluents for freezing ram spermatozoa.
Ion-pairing with acidic dyes under the described conditions is less likely because the carboxy metabolite is a zwitterion.
The nonstereospecificity and methanol adducts observed during the reaction of MTAD with the Z,Z isomer suggest the involvement of an open zwitterion.