Umami taste is evoked by ?

Ans. is 'b' i.e., Glutamic acidThere are four basic tastes namely Sweet, bitter Salty and Sour. There mechanisms of sensory transduction are :1) Sweet receptor is a G protein coupled receptor and leads to an increase in cAMP concentration in the sensory cells which results in closure of K+ channels and depolarization.2) Bitter receptors are also G protein coupled receptors and causes rise in intracellular Ca' by IP3-DAG system. Rise in intracellular Ca+2 triggers neurotransmitter release.3) Salty-tasting substances depolarize taste cells by activating amiloride-sensitive Na+ channels.4) Sour-tasting substances depolarize taste cells by raising the intracellular H + ion concentration, which causes closure of K+ channels.The umami taste is the fifth taste which is unique. The proposed mechanism of umami taste is through glutamate taste sensors (glutamate receptors) with release of neuronal glutamic acid.In nature, there are three umami substances :-i) Monosodium glutamate (MSG)ii) Disodium 51-guanosine mosphosphate (GMP)iii) Disodium 51-ionsine monophosphate (IMP)