proteinet is the neuter singular definite of protein.

proteinN

Kven

proteiiniN

Norwegian Bokmål – Kvendict-nob-fkv/src/N_nobfkv.xml:58503Edit on GitHub Suggest

proteiidnaN

Norsk-nordsamisk ordbokdict-nob-sme/src/N_nobsme.xml:175301Edit on GitHub Suggest

Case	Sg	Pl
Indef	protein	protein
Def	proteinet	proteina