biochemical proportionality coefficient relative basal rate constant The ratio of the basal activity to the maximal velocity of a reaction. The values range between 0 and 1. <n0:math xmlns:n0="http://www.w3.org/1998/Math/MathML"> <n2:lambda xmlns:n2="http://biomodels.net/SBO/"> <n2:bvar><n2:ci definitionURL="http://biomodels.net/SBO/#SBO:0000485"> b </n2:ci></n2:bvar> <n2:bvar><n2:ci definitionURL="http://biomodels.net/SBO/#SBO:0000186"> vmax</n2:ci></n2:bvar> <n2:apply> <n2:divide /> <n2:ci> b </n2:ci> <n2:ci> vmax </n2:ci> </n2:apply> </n2:lambda> </n0:math>