世界上最长的单词是哪个

pneumonoultramicroscopicsilicovolcanoconiosis [医]硅酸盐沉着病,矽肺病
以上过去在电视节目中讲过。
现在又有一说，最长的单词是“色氨酸合成酶A蛋白质”
MethionylglutaminylarginyltyrosylglutamylserylleucylphenylalanylalanylglutaminylleucyllysylglutamylarginyllysylglutamylglycylalanylphenylalanylvalylprolyphenylalanYlvalythreonylleucylglycylaspartylprolylglycylisoleucylglutamylglutaminylsErylleucyllysylisoleucylaspartylthreonylleucylIsoleucylglutamylalanylglycylalanylasparthlalanylleucylglutamylleucylglycylisoleucylprolylphenylalanylseRylaspartylprolylleucylalanylaspartylglycylpRolylthreOnylisoleucylglutaminylasPfraginylalanylthreonylleucylarfinylalanylphenylalanylalanylalanylglycylvalythreonylprolylalanylglutaminylcysteinylphenylalanylglutamylmethionylleucylalanylleuOylisoleucylarginylglutaminyllysyhistidylprolylthreonylisoleucylprolylisoleucylglycylleucylmethionyltyrosylalanylasparaginylleucylvalylphenylalanylasparaginyllysyglycylisoleucylaspartylglutamylphenylalanylthrosylalanylglutaminylcysteinylglutamyllysylvalyl