Selected substances in the metabolic reaction network of A. thaliana. We investigated the common compounds of both types of metabolic networks belonging to the classes of amino acids and carbohydrates, respectively. a) Color-coded are the pair distances of these metabolites. As before, the pair distance is the number of connections in the shortest path between two compounds. Most of the carbohydrates are characterized by small internal pair distances, while there are more links needed to connect them to the group of amino acids, which display a relatively small average internal pair distance as well. b) This graph representation shows the giant component of the metabolic reaction network of A. thaliana. All metabolites, which have also been found in the correlation network, are color-coded according to their biochemical class (see Fig. 5a).