"Our results show that reaction sequences that resemble two essential reaction cascades of metabolism, glycolysis and the pentose-phosphate pathways, could have occurred spontaneously in the earth's ancient oceans," says Dr. Markus Ralser at the Department of Biochemistry at the University of Cambridge and the National Institute for Medical Research, who led the study.
"In our reconstructed version of the ancient Archean ocean, these metabolic reactions were particularly sensitive to the presence of ferrous iron which was abundant in the early oceans, and accelerated many of the chemical reactions that we observe. We were surprised by how specific these reactions were" he added.
The conditions of the prebiotic sea were reconstructed based on the composition of various early sediments described in the scientific literature which identify soluble forms of iron as one of the most frequent molecules in the prebiotic oceans.
Alexandra V Turchyn from the Department of Earth Sciences at the University of Cambridge, one of the co-authors of the study said: "We are quite certain that the earliest oceans contained no oxygen, and so any iron present would have been soluble in these oxygen-devoid oceans. It's therefore possible that concentrations of iron could have been quite high".
The different metabolites were incubated at temperatures of 50-90˚C, similar to what might be expected close to the hydrothermal vents of an oceanic volcano, and would not support the activity of conventional protein enzymes. The chemical products were separated and analyzed by liquid chromatography tandem mass spectrometry.
Some of the observed reactions could also take place in water but were accelerated by the presence of metals that served as catalysts. "In the presence of iron and other compounds found in the oceanic sediments, 29 metabolism-like chemical reactions we
|Contact: Meera Senthilingam|