Organic Cofactors in the Electron Transport Chain: Properties and Connection the Prebiotic World

Metabolism is a critical process for biology and is of great interest to those researching geobiological processes and the origins of life. It represents a network of chemical reactions for molecular synthesis, energy conversion pathways, and cellular function. Understanding the mechanisms underlying metabolic processes gives insight into the evolution of the electrochemical processes of complex systems and informs the possible pathways by which abiotic chemistry transitioned to biochemistry. Modern proteins and enzymes utilize cofactors to mediate chemical reactions, overcoming energetic limitations. While enzymes are specific, large, and complex biological proteins, cofactors are simpler ions and molecules incorporated within the larger protein complex. Cofactors fundamentally supplement an enzyme’s catalytic role and may represent a convergence between abiotic and biotic chemistry, allowing studies of cofactors to reveal potential prebiotic processes. Here we review some of the organic nucleotide cofactors participating in the electron transport chain: their structures, capacity for energy conversion, and their putative role in the origins of life. We then make recommendations for future research topics and avenues.