Transformation of the network-derived flux space to the condition dependent k-cone. Flux solution space (left) is constructed based on the fundamental physicochemical constraints including reaction stoichiometry, maximum enzyme capacity, and limited thermodynamics (Price et al., 2003; Reed and Palsson, 2003). Condition-specific metabolite concentrations allow for a transformation that maps the flux solution space onto a solution space containing kinetic constants, or the k-cone (right). Thus, any combination of the kinetic parameters inside the k-cone is attainable by the system and satisfies both physiochemical and condition-specific constraints in the network. S, stoichiometric matrix; v, flux vector; M, matrix containing stoichiometric information and steady-state metabolite concentrations; kin vivo, vectors of in vivo kinetic values; x, metabolite concentrations.