Biomolecules Question 199
Question: Assume that a particular amino acid has an isoelectric point of 6.0. In a solution at pH 1.0, which of the following species will predominate-
Options:
A) $ H_3\overset{+}{\mathop{N}}\overset{R}{\mathop{\overset{|}{\mathop{C}}}}HCO_2H $
B) $ H_2\overset{{}}{\mathop{N}}\overset{R}{\mathop{\overset{|}{\mathop{C}}}}HCO_2H $
C) $ H_3\overset{+}{\mathop{N}}\overset{R}{\mathop{\overset{|}{\mathop{C}}}}HCO_2 $
D) $ H_2\overset{{}}{\mathop{N}}\overset{R}{\mathop{\overset{|}{\mathop{C}}}}HCO_2^{-} $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] In acidic medium Zwitter ion convert into
$ \overset{+}{\mathop{N}}H_3-\underset{R}{\mathop{\underset{|}{\mathop{C}}}}H-CO{O^{-}}+{H^{+}} $
$ \xrightarrow{{}}\overset{+}{\mathop{N}}H_3-\underset{R}{\mathop{\underset{|}{\mathop{C}}}}H-COOH $
BETA
