Basic tastes
The five tastes the tongue detects directly: sweet, sour, salty, bitter and umami.
Also: five tastes, primary tastes
Taste buds carry receptors for five kinds of taste. Sweet signals sugars. Salty signals sodium. Sour signals acids. Bitter responds to a very wide range of compounds, and umami to glutamate and related substances. All five can be sensed over the whole tongue. The old tongue map showing separate zones is wrong. Most of what people call flavour is in fact smell, working together with taste. The burn of chilli and the grip of tannin are felt by touch and pain nerves.