The longest word in the world (if proteins count as words)
Titin, its shortened name, is the longest protein discovered so far, and has the longest name in existence, at 189 819 letters long. Course, that’s just if you consider it a word.
Methionylthreonylthreonylglutaminylarginyltyrosylglutamylserylleucyl
(Source: sarahmcculloch.com)