Axit 2-aminopropanoic (alanin): $CH_3-CH(NH_2)-COOH$.
$CH_3-CH(NH_2)-COOH + NaOH \to CH_3-CH(NH_2)-COONa + H_2O$
$CH_3-CH(NH_2)-COOH + HSO_3H \to CH_3-CH(NH_3SO_3H)-COOH$
$CH_3-CH(NH_2)-COOH + CH_3OH \buildrel{{HCl, t^o}}\over\rightleftharpoons CH_3-CH(NH_2)-COOCH_3+ H_2O$