Re: Why is sugar sweet?

Good question. First, the technical stuff: the tongue contains many many
flavor receptors, some of which are specific for sugar molecules. When
sugar hits the tongue, the molecules bind to the sugar receptors, and the
receptor triggers a nerve impulse which travels to the brain and says,
"sweet." Because these sugar receptors only recognize a part of the sugar
molecule, they are easily fooled by other molecules which have this piece
of the sugar molecule; this is why saccharine and aspartame taste sweet.

But why go to the trouble of telling your brain, "sweet," whenever you eat
sugar? Sugar in the simplest form of carbohydrate and, as such, is the
best source of energy for the body to consume. So, the taste system was
developed to tell the brain when "good food" was around, so that you would
know to eat lots of it. We describe the brains view of "sugar is good" as
"sweet".