With light we know that frequency varies along a linear spectrum that contains all colors. But what about flavor and/or scent? It would seem that these sensory data would be more multidimensional but what factors actually cause flavors and scents at the molecular/chemical level? Is there more to it than Ph-level? Are there actual chemical reactions involved to generate specific flavors and what is it exactly that is getting communicated to taste buds other than a certain level of electrostatic potential?

So, I think you're asking how humans/animals quantify scents.

So, I think you're asking how humans/animals quantify scents.

Interesting. So there are these various methods for analyzing the composition of various flavors/scents in terms of numerous compounds, but what is it about each that produces a particular effect? It must be more than just the pH level of the substance in question, right?

Interesting. So there are these various methods for analyzing the composition of various flavors/scents in terms of numerous compounds, but what is it about each that produces a particular effect? It must be more than just the pH level of the substance in question, right?

 

Animals have many custom fit receptors that only bind to certain molecular shapes or functional groups. For example, the thiol group, [ce] -SH [/ce], is especially smelly to humans. So this molecule:

 

 

2-aminothiophenol, has a very strong, rotten egg/dead animal smell. Presumably because of the[ce] -SH [/ce] group there, but the [ce] C_{6}H_{5}NH_{2} [/ce] [aniline] group has also been known to be smelly so I'm speculating a bit here. I have smelled this compound though, very gross.

Animals have many custom fit receptors that only bind to certain molecular shapes or functional groups. For example, the thiol group, [ce] -SH [/ce], is especially smelly to humans. So this molecule:

 

 

2-aminothiophenol, has a very strong, rotten egg/dead animal smell. Presumably because of the[ce] -SH [/ce] group there, but the [ce] C_{6}H_{5}NH_{2} [/ce] [aniline] group has also been known to be smelly so I'm speculating a bit here. I have smelled this compound though, very gross.

So not only are the effects of the charge/pH of the substance being registered but also the shape of the molecule? How can a cell decipher the shape of a molecule?

Wikipedia's article on Aroma compounds has some interesting info.