 This is a schematic representation (with a high degree of abstraction) of the mechanism of protein synthesis, which can be instantiated with details of DNA base sequence, complementary RNA sequence, and the corresponding order of amino acids in the protein produced by the more specific mechanism. Molecular biology textbooks are replete with diagrams of mechanism schemas. A mechanism schema can be instantiated to yield a description of a particular mechanism. In contrast, a mechanism sketch cannot (yet) be instantiated; components are (as yet) unknown. Sketches have black boxes for missing components or grey boxes whose function is known but whose entities and activities that carry out that function are not yet elucidated. Such sketches guide new research to fill in the details (Craver and Darden 2013).