Longest Word

The longest word contains 1,909 letters and has been published in a dictionary. It is the term for the formula C1289H2051N343O375S8, a protein that consists of 267 amino acids. In third grade, both of my children received a complimentary dictionary from our elementary school. The last page contains the longest word in the English language which is noted below.

The Longest Word in the English Language

Methionylglutaminylarginyltyrosylglutamylserylleucylphenylalanylalanylglutaminylleucyllysylglutan
ylarginyllysylglutamylglysylalanylphenylalanylvalylprolylphenylalanylyalylthreonylleucylglcycylas
partylprolylglicylisoleucyglutamylglutamimlserylleucyllysylisoleucylaspartylthreonylleucylisoleuc
ylglutamylalanylglyclyalanylaspartylalanylleucyglutamylleucylgluycylisoleucylproluylphenylalanyse
rylaspartyprolylleucelalanylaspartylglycylprolylthreonylisolleucyglutaminylasparagimylalanythreon
ylleucylarginylalanylphenylalanylalanylalanylglycylvalylthreonylprolylalanylglutaminylcysteinylph
enylalanylglglutamylmthionylleucalanylleucylisoleucylarginylglutaninyllysylhistidylpooyuthreonyoi
soleucylprolylisoleuclglycylleucylleucylmethiolnyltyrosylalanylasbaraginylleucylvalylphenylalanyl
sparaginyyllysylglycylisoleucylaspartylglutamylphenylalanylyltyrosylalanylglutaminylcysteinylglut
amyllysylvalylglycylvalylspartylserylvalylleucylvallalanylaspartylvalylprolylvalvlglutaminylglutam
ylserylalanylprolyiphenylalalrginylglutaminylalanylalanylleucylarginylhistidylasparaginylvalylalal
prlylisoleucylphenylalanylisoleucylcysteinylprolyprolylaspartylalanylaspartyspartyleucylleucylargi
nylglutaminylisoleucylalanylseryltyroslglycylarginylglycyltyrosylthreonyltyrosylleucylleucylseryla
rginlalanylglycylvalylthreonylglycylalanylglutamylasparaginylarginylanylalanylleucylprolylleucylas
paaginylhitidylleucylvalylalanyllysylleucyllysylglutamyltyrosylasparagimylalanylalanyprolylprolyll
eucylglutaminylglycyphenlalanylglycylisoleyucylserylalanylprolylaspartymgmutaminylvalyllysylalanyl
alanylisoleucylalspartylalanylglycylalanylalanylglycylalanylasoleucylserylglycylserylalanylisoleuc
ylbalyllysylisoleucylisoleucylglutamylglutaminylhistidylasparaginlisoleucylglutamylpronylgluotamyl
lysylmethionylluecylalanylalanyoeucyllysylvalylphenylalanylvalylglutamilylprolylmethionyllysylalan
ylalanylthreonylarginylserine

Source: A Student’s Dictionary & Gazetteer, 19th edition, 2011, pg. 524