In a sample consisting of lysine, leucine, and glutamic acid, which will be eluted last from an anion exchange resin at pH 7?
A) all three will be eluted at the same time
B) lysine
C) leucine
D) glutamic acid

Question

Quizplus · Accepted Answer

At pH 7, glutamic acid, which is an acidic amino acid, will be negatively charged due to the deprotonation of its side chain carboxyl group. An anion exchange resin, which binds negatively charged species, will retain glutamic acid the longest, causing it to be eluted last.

In a Sample Consisting of Lysine, Leucine, and Glutamic Acid