Screenshot of TinkerCell. This is a screenshot from TinkerCell showing a system involving three cells. Models are constructed using components available in the parts catalog, which is located at the top left. Some of the components used in this system are cells, membrane proteins, fluorescent proteins, small molecules, and genes. Below the parts catalog is the catalog of reactions, which includes reactions such as enzyme catalysis and transcriptional regulation. A history window is located at the top right. The plot window can hold multiple plots, including 3D surface plots.