The control of cell metabolism for homogeneous vs. heterogeneous enzyme systems

摘要: Metabolic control theories, based on such parameters as “elasticity coefficients” and “flux-control coefficients”, have emergd in recent years. These offer a potentially unifying, holistic paradigm for understanding the regulation of cell metabolism. Much foundation relies supposition that system is homogeneous bulk-phase solution individual enzymes. We examine some tenets light increasing knowledge enzyme organization vivo . cast into more general form applicable to linear kinetic regime, using newly defined unit—the power, which allows complete specification terms any all factors bear upon conversion free substrate product situ Extending theory heterogeneous states organization, we make formal distinction between “solution connectivity” “structural multienzyme system. The use “structural” rate expressions leads definition flux-control coefficient specifies interdependence processes an organized problems limitations applying experimental analysis real systems are discussed. “We arrived at last point comes rather close what might be ‘molecular cellular activity’, only discover ‘controlling’ molecules themselves acquired their specific configurations, key power control, by virtue membership population cell, hence under ‘cellular control’.” ( Weiss, 1963 ).