<prompt> Which of the following biochemical reaction is involved in conversion of Histidine to histamineDecarboxylationCarboxylationDeaminationOxidation  <response>: Histidine to Histamine is Simple Decarboxylation step, requiring Vitamin B6 PLP-Pyridoxal Phosphate as coenzyme. Other examples of Simple Decarboxylation are: Tryptophan -Tryptamine Tyrosine -Tyramine DOPA -Dopamine Serine -Ethanolamine Cysteine-Beta Mercapto Ethanol Note: All these are mainly Amino Acids which undergo Decarboxylation to produce Amine Similarly, from Amino Acid, if Amino group is removed, Acid is formed. BUT Decarboxylation of Glutamate and Lysine does not form amine. Lysine - Cadaverine a foul smelling diamine Glutamate - GABA Gamma Amino Butyric Acid Fig.: Different factors required by Carboxylases and decarboxylases 