Amino acids are amphoteric molecules. Explain this statement.

• Amphoteric molecules can act both as a base and an acid.
• Amino acids have both acidic (carboxyl) and basic amino groups.
• At high concentrations of hydrogen ions, the negatively charged carboxyl group will accept protons and become uncharged and the overall charge of the amino acids becomes positive.
• At low concentration of hydrogen ions, the positively charged amino group loses its proton and the overall charge of molecule becomes negative.