If the choice of the research scientist or reactor designer is the condition in line with, rQSSA, where [ET] is ≫ [ST], then it is very probable that all the substrate molecules should be transformed into products within the chosen duration of assay as expected in a single turnover catalytic event without the need for extra recycling of the enzyme molecules for another round of catalytic hydrolysis of the substrate. On the other hand, the choice may be one in which [ST] ≫ [ET] in which a fraction of the substrate is transformed (turnover event) into the product, leaving behind a substantial amount of free substrate and fragments . The enzyme has opportunity to be recycled meeting any of the free substrate or fragments. Catalytic cycling needs to be classified into positive recycling (product destined) and negative recycling (deactivation of activated ES and ultimately dissociation into free S and E). The focus is always on the positive aspect.