The bitter taste is mediated by the action of: (A) Guanyl cyclase, (B) G protein, (C) Tyrosine kinase, (D) Epithelial Na+ chain
Answer is B. Sweet- G protein coupled increased in cAMP causing closure of K+ channels.
Salt- Opening of amiloride sensitive Na+ channels
Sour- Increased intracellular H+ concentration causing closure of K+ channels
Bitter- G protein-coupled increase in intracellular Ca++ triggering neurotransmitter release.