Reference:
                                                  
                                                    
      - Intelmann, Daniel; Batram, Claudia; Kuhn, Christina; Haseleu, Gesa; Meyerhof, Wolfgang; Hofmann, Thomas Three TAS2R Bitter Taste Receptors Mediate the Psychophysical Responses to Bitter Compounds of Hops (Humulus lupulus L.) and Beer, 2009/09/01, DOI: 10.1007/s12078-009-9049-1
 
                                                  
                                                  Comment:
                                                  
                                                    Activated: the receptor is activated. But exact value is not given or cannot be measured.