Question

Which of these statement is NOT true about amino acids?

• A. They contain separate parts with a positive and negative charges
• B. They become zwitter-ionic when dissolved in water
• C. They can be a zwitter-ion even in solid state
• D. There is no internal transfer of charge in amino acids

Answer 1

The correct option is D

There is no internal transfer of charge in amino acids

Amino acids contain an alkali amine group and an acidic carboxyl group, both of which exists in the ionic form in solutions. The caboxyl group loses a proton, which is taken up by the amine group. Therefore amino acids contain both positive and negative ion, forming a zwitter ion. Diffraction studies reveal that amino acids also exist as zwitter ions in the solid state.