Just as sites on postsynaptic regions of neurones react to chemicals, so too do sites on microvilli. This helps transduce chemical properties to electrochemical properties. 5.The 4 basic taste receptors are found , chiefly, in different places in the mouth. The tongue's tip is mostly sensitive to what is sweet and salty. Its sides favour what is sour.
Taste is a chemical sense, depending on what substances do when broke down, and affected by saliva.
Lose Na and the result will be a salt craving. 7.Bitter and sweet substances do not ionize. Sweetness likely is related to sugar content. Bitterness may be related to many poisons, and deters us. It often has strong motivational effects.