Subject: Why do salts (NaCl, KCl, MSG etc.) enhance the flavors in food?

It is well known that adding salt a seemingly bland food enhances the 
flavors of that food.  An example, soup...  After the addition of table 
salt the certain flavors seem to appear(the flavor of onions, spices, 
etc.)  Monosodium Glutamate is also used as a flavor enhancer.  Adding 
Lemon to many non-citrus fruits seems to enhance the flavors as well.  I 
have often wondered if this was directly related to increasing the 
conductivity of the foodstuff when salt is added...  Would the addition of 
a small amount of surfactant allow us to taste even more insoluble parts 
of our foods? Do our tastebuds and other flavor receptors work better in a 
more conductive environment?  What are the various electrochemical 
mechanisms at work when we "taste"??? How do salts enhance these 
mechanisms?

Re: Why do salts (NaCl, KCl, MSG etc.) enhance the flavors in food?