Odors are more complicated than something “stinky” or “smelly.” They are made up of many different molecules, but all scents are based on the element of carbon. Odors with similar molecules will smell similar and vice versa. The odors with similar molecule patterns are put into families. For example, the terpenes family contains oranges, lemon, and grapefruit. They each share the same functional group, which is a common pattern found in the structures. A molecule is not limited to one functional group though. They can be considered to be apart of many different families with the different functional groups found.
Also, actually smelling the odor is complicated. First, the odors attach to your odorant receptors in your nose. This triggers the olfactory receptor cells to send electric signals through the glomeruli. After, the signals are transmitted to higher regions of the brain where it can be stored as a memory. You don’t really think of all the little science your body is doing right now. So many little molecules are going in and out of your body right now and you aren’t very conscious about it. That’s what makes it so complicated.
Also, actually smelling the odor is complicated. First, the odors attach to your odorant receptors in your nose. This triggers the olfactory receptor cells to send electric signals through the glomeruli. After, the signals are transmitted to higher regions of the brain where it can be stored as a memory. You don’t really think of all the little science your body is doing right now. So many little molecules are going in and out of your body right now and you aren’t very conscious about it. That’s what makes it so complicated.