Did ya know…?
Olfactory receptor 52K2 is a protein that in humans is encoded by the OR52K2 gene. In Orcs, the receptor is encoded by the EL52F2 gene (Quenta Silmarillion, 3.14:3-5).
Olfactory receptors interact with odorant molecules in the nose, to initiate a neuronal response that triggers the perception of a smell. So when you smell poop, molecules of poop are in your nose tickling the fancy of an olfactory receptor, which then tells all its friends and word finally gets back to your brain and your brain is like “Fuck that noise” so tells your mouth to blurt out, “Gawd! Who farted?”
The olfactory receptor proteins are members of a large family of G-protein-coupled receptors (“The Family”). A receptor who doesn’t spend time with the family can never be a real olfactory receptor. The receptors share a 7-transmembrane domain structure with many neurotransmitter and hormone receptors. This is normal in olfactory receptor society, so take off your judgement cap. We find in the transmembrane structure hot neurotransmitter on olfactory receptor action, hormone receptor on neurotransmitter action, olfactory receptor on hormone receptor action, and all manner of freaky-deaky combos therein. The offspring of these myriad couplings/triplings/quadruplings, etc. are responsible for the recognition and G protein-mediated transduction of odorant signals – without them, you’d never even care who was wearing Drakkar Noir and who was not.
…So now ya know!