The chemical reactions behind the formation of common metabolites in modern organisms could have formed spontaneously in the earth’s early oceans, questioning the events thought to have led to the origin of life.
In new research funded by the Wellcome Trust, researchers at the University of Cambridge reconstructed the chemical make-up of the earth’s earliest ocean in the laboratory. The team found the spontaneous occurrence of reaction sequences which in modern organisms enable the formation of molecules essential for the synthesis of metabolites such as amino acids, nucleic acids and lipids. These organic molecules are critical for the cellular metabolism seen in all living organisms.
The detection of one of the metabolites, ribose 5-phosphate, in the reaction mixtures is particularly noteworthy, as RNA precursors like this could in theory give rise to RNA molecules that encode information, catalyze chemical reactions and replicate.
It was previously assumed that the complex metabolic reaction sequences, known as metabolic pathways, occurring in modern cells were only possible due to the presence of enzymes. Enzymes are highly complex molecular machines that are thought to have come into existence during the evolution of modern organisms. However, the team’s reconstruction reveals that metabolism-like reactions could have occurred naturally in our early oceans, before the first organisms evolved. More here Metabolism may have started in our early oceans before the origin of life.