  Processes involving multi-input multi-step reaction cascades are used in
developing novel biosensing, biocomputing, and decision making systems. In
various applications different changes in responses of the constituent
processing steps (reactions) in a cascade are desirable in order to allow
control of the system's response. Here we consider conversion of convex
response to sigmoid by "intensity filtering," as well as "threshold filtering,"
and we offer a general overview of this field of research. Specifically, we
survey rate equation modelling that has been used for enzymatic reactions. This
allows us to design modified biochemical processes as "network components" with
responses desirable in applications.
