Systems Chemistry: Logic Gates, Arithmetic Units, and Network Motifs in Small Networks

AbstractHow much “systems chemistry” really exists within small networks? To answer this question, the authors study tertiary networks that facilitate molecular replication through all Boolean logic operations and show how such gates can be wired together to perform computational and feed‐forward based network motifs (see graphic).magnified imageA mixture of molecules can be regarded as a network if all the molecular components participate in some kind of interaction with other molecules—either physical or functional interactions. Template‐assisted ligation reactions that direct replication processes can serve as the functional elements that connect two members of a chemical network. In such a process, the template does not necessarily catalyze its own formation, but rather the formation of another molecule, which in turn can operate as a template for reactions within the network medium. It was postulated that even networks made up of small numbers of molecules possess a wealth of molecular information sufficient to perform rather complex behavior. To probe this assumption, we have constructed virtual arrays consisting of three replicating molecules, in which dimer templates are ca