Last discovered taste sensation -
Ans. is 'd' i.e., Umami o Umami taste sensation is the most recent one, discovered in early 1900s.Taste sensationso There are four basic tastes namely Sweet, bitter, Salty and Sour. There mechanisms of sensory transduction are:o There are different mechanisms of sensory transduction.1) Sweet receptor is a Gprotein 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+2 by IP3-DAG system. Rise in intracellular Ca+2 triggers neurotransmitter release.3) Salty-tasti ttg 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.o 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.
Sweet
Sour
Bitter
Umami
General Principles of Gastrointestinal Function