Sprecher
Beschreibung
To understand the potential for life elsewhere, it is important to try to detect organic molecules on other planets, but also to understand the “pattern distributions” of organics – that is, the relative amounts of different organic molecules in a system. It is possible that organic distribution patterns could be a biosignature, but only if they can be deconvoluted from non-biological organic chemistry. We investigated the reactions of pyruvate and glyoxylate (two prebiotically relevant organic precursors) in systems containing reactive iron minerals, driving reduction and reductive amination reactions to produce hydroxy acids and amino acids, respectively. These reactions were studied in the context of varying several environmental variables relevant to conditions that might exist in a variety of planetary environments as well as on the early Earth when life emerged: pH, the redox state of iron in the mineral, and ammonia concentration. Our results show that the positioning of the pyruvate / glyoxylate reaction network in the geochemical parameter space determines the organic product distribution pattern that results. This is significant for origin of life chemistry in which the composition and function of oligomers could be affected by the environment-driven distribution of monomers available. Also, for astrobiology and planetary science where organic distribution patterns are sometimes considered as a possible biosignature, it is important to consider geochemically-driven abiotic reactions that might produce similar effects.
