In reaction network theory, the Volpert graph plays a very important role. As an abstract idea of reaction kinetics, it is a directed bipartite graph. The vertex set contains the chemical components and the reaction steps, which are the two disjoint classes of the graph. There is an edge between a component and a reaction if and only if the reactant complex contains the component; otherwise, there is an edge between a reaction and a component if and only if the product complex contains the component.