G-protein coupled receptors (GPCRs) constitute the targets of about 40 % of all the pharmaceutical drugs in the market and, among other functions, a large portion of the family detects odorants and a variety of tastant molecules. Computational techniques are instrumental to understand structure, dynamics and function of the cascades triggered by these receptors. As an example, here we report our own computational work aimed to dissect GPCR molecular mechanisms for chemical senses. The implications of our work for systems biology and for pharmacology are discussed.