This package contains different types of nodes needed for representing a substance in a biochemical pathway.
Substances are connected to reactions through connectors placed
on the rim of the circle representing the substance.
The substance models are specified by extending the partial models of substance nodes in
Substances
and adding additional attributes and equations.
The
Substances
model is used when the concentration in a substance node is allowed to change without restrictions during a simulation, while
BoundarySubstances
is used when the concentration can only be changed using events. This correspond to species with the fixed or boundary attribute set in SBML.
The
AmbientSubstance
is a substance used as a reservoir in reactions. This corresponds to the empty list of reactants or the empty list of products in an SBML reaction.
When the concentration is not determined by reactions, the
SignalSubstance
model is used. Then the substance concentration is regulated by external equations, and it corresponds to SBML species changed by any SBML rules.