<prompt> Which of the following is FALSE regarding amino acid metabolism?Histamine is a product of decarboxylation of histidineThreonine provides the thioethanol moiety for biosynthesis of coenzyme AOrnithine serves as a precursor of both spermine and spermidineSerotonin and melatonin are metabolites of tryptophan  <response>: Serine provides the thioethanol moiety of coenzyme A, not Threonine. Because acetyl-CoA has a much higher energy content than acetic acid, it combines readily with substances in reactions that would otherwise require outside energy. Acetyl-CoA is therefore often called active acetate. Ref: Barrett K.E., Barman S.M., Boitano S., Brooks H.L. 2012. Chapter 1. General Principles Energy Production in Medical Physiology. In K.E. Barrett, S.M. Barman, S. Boitano, H.L. Brooks Eds, Ganongs Review of Medical Physiology, 24e. 