The sense of taste is pivotal to evaluating food and discriminating nutrients from toxic substances. The five basic tastes commonly recognized are sweet, umami, bitter, sour, and salty. Among these, bitter taste perception is related to the protection of the organism against the ingestion of spoiled or poisonous food compounds and is based on a multiscale signal transduction process. The first stage of this process is established through taste receptors, specific proteins that, because of conformational changes due to the interaction with specific agonists, permit the triggering of these signalling transduction pathways. Bitter taste receptors are members of a sub-family (Class T) of G protein-coupled receptors (GPCRs), called the “Taste 2 receptor family” (TAS2R).