2022 Phase 2 BiomoleculesAmino acids - ionisable nature and zwitterion Medium Question 36 of 107 in Biomolecules

Given below are two statements: Statement I: Amino acids have a property of ionizable nature of $-NH_2$ and $-COOH$ groups, hence have different structures at different pH. Statement II: Amino acids can exist as Zwitterionic form at acidic and basic pH. In the light of the above statements, choose the most appropriate answer from the options given below:

A Statement I is incorrect but Statement II is correct
B Both Statement I and Statement II are correct
C Both Statement I and Statement II are incorrect
D Statement I is correct but Statement II is incorrect

The answer is B.

Solution

Statement I is correct. The source key also treats Statement II as correct, reasoning that zwitterion formation takes place at the isoelectric point, which can be at acidic or basic pH depending on the amino acid.

Concept Amino acids - ionisable nature and zwitterion

Biomolecules in past papers

107 questions from this chapter have appeared across 26 exam years.