Abiotic Photosynthesis: From Prebiotic Chemistry to Metabolism

The basic concepts necessary to understand the origin of life are presented. The existing models conducting to the emergence of biochemistry from geochemistry on Earth are introduced. The chapter is focused on abiotic photosynthesis as a way to capture energy and generate the core of central metabolism. Universality in intermediate metabolism, mineral catalysis, hydrothermal vents, and the iron-sulfur proposals are discussed. Special emphasis is given to the model of non-enzymatic prebiotic metabolism that can potentially connect the RNA world and the compartmentalization in protocells approach. Catalysis in mineral surfaces is suggested as the main mechanism for the possible origin of the central metabolic pathways. Candidate semiconductor minerals such as zinc sulfide could have driven this prebiotic chemistry in the young planet. A shallow-water hydrothermal vent system is presented as a model environment where the first microorganisms on Earth used the suggested non-enzymatic chemical reactions as a pioneer mechanism for carbon dioxide fixation and energy storage that resulted in prebiotic metabolism.