Biologically, what differentiates a bad smell from a good smell?

Question

I guess pretty much the title. Does bad smells trigger some kind of different olfactory receptors than good smells, or is it really just our brains with “personal preferences”?

In: Biology

Answer 1

There’s a lot of subjectivity to it since our own individual experiences are tied to smell (our amygdala is a big part of what perceives smell), but one factor is often larger molecules smell worse. There’s a big thread on a [similar eli5 post](https://www.reddit.com/r/explainlikeimfive/s/Y852rRKvJi) that might be useful.