A BLOCK-DIAGRAMMATIC APPROACH TO METABOLIC CONTROL ANALYSIS

1. We have presented a block-diagrammatic approach for control analysi s of metabolic pathways. In this approach the control structure of a m etabolic pathway is represented by a block diagram which is drawn in a heuristic fashion from the reaction pattern of the pathway. 2. By sim plifying the block diagram in a systematic manner, the flux control co efficients of the enzymes are readily evaluated in terms of their elas ticity coefficients and velocities. 3. The following metabolic pathway s are examined here: (a) a linear pathway in the absence of feedback a nd feedforward regulation, (b) a linear pathway in which the first enz yme is inhibited by the last variable metabolite, (c) a linear pathway with multiple feedback loops, (d) a branched pathway, and (e) a paral lel pathway containing isoenzymes.