Q. An electric current is passed through an aqueous solution of a mixture of alanine (isoelectric point 6.0) glutamic acid (3.2) and arginine (10.7) buffered at pH6. What is the fate of the three acids?
A) Glutamic acid migrates of anode at pH6. Arginine present as a cation and migrates to the cathode. Alanine in a dipolar ion remains uniformly distributed in solution.
B) Glutamic acid migrates to cathode and others remain uniformly distributed in solution.
C) All three remain uniformly distributed in solution.
D) All three move to cathode.
Explanation
(a)
At pH = 6, glutamic acid exists as a dianionic species and migrates to anode while arginine exists as cationic species and moves to cathode. Alanine does not migrate to any electrode at its isoelectric point.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.