hydroxylase

The story

1. Proto-Indo-European*wed-
2. Proto-Indo-European*wódr̥
3. Proto-Hellenic*údōr
4. Ancient Greekῡ̆̔́δωρ (hū̆́dōr)
5. Ancient Greekὑδρο- (hudro-)
6. Frenchhydro-
7. Proto-Indo-European*ǵenh₁-
8. Proto-Indo-European*ǵénh₁os
9. Proto-Hellenic*génos
10. Ancient Greekγένος (génos)
11. Frenchhydrogène
12. Englishhydrogen
13. Proto-Indo-European*h₂eḱ-der.?
14. Ancient Greekὀξύς (oxús)
15. Ancient Greekγένος (génos)
16. Frenchoxygène
17. Englishoxygen
18. Proto-Indo-European*swel-der.?
19. Ancient Greekῡ̔́λη (hū́lē)
20. Englishhydroxyl
21. Proto-Indo-European*dwóh₁
22. Proto-Indo-European*trísinflu.
23. Proto-Indo-European*dwís
24. Ancient Greekδιά (diá)
25. Ancient Greekδῐᾰ- (dĭă-)
26. Proto-Indo-European*steh₂-
27. Proto-Indo-European*stísteh₂ti
28. Proto-Hellenic*hístāmi
29. Ancient Greekῐ̔́στημῐ (hĭ́stēmĭ)
30. Ancient Greekδῐῐ̈́στημῐ (dĭĭ̈́stēmĭ)
31. Ancient Greekδῐᾰ́στᾰσῐς (dĭắstăsĭs)
32. Englishdiastase
33. English todayhydroxylase

From hydroxyl + -ase.