{'fraction_non_alphanumeric': 0.02924901185770751, 'fraction_numerical': 0.011857707509881422, 'mean_word_length': 5.33, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Energetics of Biomolecule Synthesis on Early Earth

Among the most plausible environments for the origin of life are marine hydrothermal systems, where geochemical energy sources and refugia from sterilizing meteorite impacts would have been plentiful. Here, values of Gibbs energy were calculated for the formation of individual cellular building blocks from inorganic reactants. In our model, corresponding redox reactions occurred at the interface between two end-member fluids—low temperature (25 °C), mildly acidic (pH 6.5), relatively oxidized (E h -0.30 mV) seawater and moderately hot (140 °C), alkaline (pH 9), reduced (E h -0.71 mV) hydrothermal vent fluid. The thermodynamic calculations demonstrate that biomass synthesis is most favorable at moderate temperatures, where the energy contributions from HCO 3 - and H + in seawater coupled to the reducing power in hydrothermal fluid are optimized. The models further show that the net synthesis of cellular building blocks may yield small amounts of energy over the ranges of temperature and chemical composition investigated. This is counter to conventional wisdom for anabolic processes and lends further support to marine hydrothermal systems as particularly favorable sites for the emergence of life.