This pathway map demonstrates the complexity of even a simple, widely utilized, and relatively well understood process such as glucose fermentation to ethanol. Glucose and ethanol are identified.
Credit or Source: E. Gasteiger et al., “Expasy: The Proteomics Server for In-Depth Protein Knowledge and Analysis,” Nucleic Acids Res. 31, 3784–88 (2003). Screenshot source: web.expasy.org/pathways/
U.S. DOE. 2006. Breaking the Biological Barriers to Cellulosic Ethanol: A Joint Research Agenda, DOE/SC/EE-0095, U.S. Department of Energy Office of Science and Office of Energy Efficiency and Renewable Energy. (p. 128) (website)