Constraint |
A restriction that must be satisfied for a solution to be permitted. It limits and defines a space where the feasible flux distributions occur. |
Elementary modes |
Unique sets of nondecomposable reactions within any network that are able to both sustain a steady state flux and operate independently. |
Extreme pathways |
Unique and minimal sets of reactions within any network that correspond to the extreme rays of a polyhedral cone and therefore completely characterize the steady state capabilities of metabolic networks. |
Flux distribution |
A specific set of reaction fluxes in a network. |
Isotopic labeling experiment |
An experiment in which isotopically labeled precursor (generally 13C-labeled) is fed to the target, and the subsequent redistribution of the label is measured as a time course or after the system has reached an isotopic steady state. |
Metabolic control analysis |
A means to investigate the sensitivity of the steady state properties of a network by quantitative determination of enzymatic control coefficients. |
Network robustness |
The potential of a network to tolerate and respond to perturbation cause by a genetic and/or an environmental change. |
Objective function |
A function that must be maximized or minimized, reducing the solution space and defining fluxes that satisfy the objective of the model. |
Steady state |
The state wherein the quantity of a compound being produced is equal to the quantity being consumed. |
Stoichiometric matrix |
A matrix wherein, for each reaction, the stoichiometry of the metabolism is represented by a column and each metabolite is represented by a row. |