There are five basic tastes that can be perceived by the human tongue. These are bitterness, sourness, saltiness, sweetness and savoriness. Bitter is the most sensitive among these tastes and is detected by the taste buds at the back of tongue and in the throat. Sour on the other hand is indicative of acidity and helps in its perception. The taste buds along the side of the tongue perceive sourness. Saltiness is also recognized by these buds. Check out the video linked below…apparently, this dog’s entire tongue is wary of the sourness of lemons!