Chapter 9 Flashcards
amino acid
One of 20 building blocks of proteins.
amphiprotic
A molecule that can act as both a proton donor and a proton acceptor. The intermediate species of polyprotic acids are amphiprotic.
diprotic acids and bases
Compounds that can donate or accept two protons.
hydrolysis
“Reaction with water.”
isoelectric focusing
A technique in which a sample containing polyprotic molecules is subjected to a strong electric field in a medium with a pH gradient. Each species migrates until it reaches the region of its isoelectric pH. In that region, the molecule has no net charge, ceases to migrate, and remains focused in a narrow band.
isoelectric point
The pH at which the average charge of a polyprotic species is 0. Same as isoelectric pH.
isoionic point
The pH of a pure solution of a neutral, polyprotic molecule. The only ions present are H+, OH-, and those derived from the polyprotic species. Same as isoionic pH.
polyprotic acids and bases
Compound that can donate or accept more than one proton.
speciation
Describes the distribution of an element or compound among different chemical forms.
zwitterion
A molecule with a positive charge localized at one position and a negative charge localized at another position.