The longest word methionyl (which appears 337 times, including as the first component) threonyl (which appears 2083 times, initially as the second and third component) glutaminyl (which appears 724 times, initially as the fourth component) alanyl (which appears 1632 times, initially as the fifth component) prolyl (which appears 1834 times, initially as the sixth component) phenylalanyl (which appears 672 times, initially as the eighth component) leucyl (which appears 1694 times, initially as the thirteenth component) seryl (which appears 1910 times, initially as the fifteenth component, and for the last time as the penultimate component) valyl (which appears 2414 times, initially as the sixteenth, seventeenth and eighteenth component) glutamyl (which appears 2324 times, initially as the twentieth component) glycyl (which appears 1731 times, initially as the twenty-first component) histidyl (which appears 391 times, initially as the thirtieth component) isoleucyl (which appears 1657 times, initially as the thirty-first component, and not including one occurrence of isoleucine as the final component) tryptophyl (which appears 401 times, initially as the forty-second component) arginyl (which appears 1405 times, initially as the forty-fifth component) aspartyl (which appears 1430 times, initially as the forty-sixth component) lysyl (which appears 2199 times, initially as the sixty-ninth component) asparaginyl (which appears 902 times, initially as the seventy-ninth component) tyrosyl (which appears 829 times, initially as the eighty-third component) cysteinyl (which appears 356 times, initially as the nine hundred and thirty-second component) isoleucine (which appears once, as the final component)
The chemical composition of titin, the largest known protein Longest known word overall by magnitudes. Attempts to say the entire word have taken two[1] to three and a half hours.[2] Technical; not in dictionary; whether this should actually be considered a word is disputed
