| zwieback | Sweetened bread which has been baked twice, preferred for infant feeding during teething. Origin: Ger. Twice-baked (05 Mar 2000) |
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| Zwischenferment | Synonym: glucose-6-phosphate dehydrogenase. Origin: Ger. Zwischen, between, + Ferment, fermentation (05 Mar 2000) |
| zwitter hypothesis | That an amphoteric molecule (e.g., an amino acid) has, at its isoelectric point, equal numbers of positive and negative charges, thus becoming a zwitterion. (05 Mar 2000) |
| zwittergents | Detergents that are zwitterionic; often used as surfactants and in the release of proteins from biomembranes. Synonym: zwitterionic detergent. Origin: zwitterion + detergent (05 Mar 2000) |
| zwitterion | <chemistry> A zwitterion is a dipolar ion that is capable of carrying both a positive and negative charge simultaneously. The best example of this are amino acids which have a basic NH2 group and an acidic COOH group. What usually happens is that the H from the COOH group (carboxylic acid end) migrates to the NH2 group and this causes what is known as a dipolemoment. Synonym: ampholyte ions, dipolar ions. (11 May 1997) |
| zwitterionic | Denoting a substance with the properties of a zwitterion; e.g., at pH value of 6.11, alanine is zwitterionic. (05 Mar 2000) |
| zwitterionic buffer | Buffer whose structure can include opposite charges. Synonym: dipolar buffer. (05 Mar 2000) |
| zwitterionic detergent | Detergents that are zwitterionic; often used as surfactants and in the release of proteins from biomembranes. Synonym: zwitterionic detergent. Origin: zwitterion + detergent (05 Mar 2000) |
| zwitterionic surfactant | A dipolar surfactant. (05 Mar 2000) |
| zwitterions | Synonym: dipolar ions. See: zwitter hypothesis. Origin: Ger. Zwitter, hermaphrodite, mongrel + ion (05 Mar 2000) |