The sugar phosphate reaction sequences of glycolysis and the pentose phosphate pathway supply modern cells with the intermediates required for the synthesis of RNA, lipids and amino acids. Today, these reactions are catalysed by sophisticated metabolic enzymes, but a new study by Keller, Turchyn and Ralser published in Molecular Systems Biology shows that the origin of these pathways could have been much simpler. Replicating conditions of an Archean sea, considering conditions of the eon before the atmosphere was oxygenated (~3.5- 4 billion years ago) they could find reactions which mimic glycolysis and the pentose phosphate pathway to occur also in the absence of enzymes. This finding triggers the hypothesis that first forms of metabolism were of environmental, or pre-biotic origin, and proposes that the origin metabolism could have been an early event during the origin of life.
Links: "Non‐enzymatic glycolysis and pentose phosphate pathway‐like reactions in a plausible Archean ocean", by Keller, Turchyn and Ralser,
http://msb.embopress.org/content/10/4/725, Mol Syst Biol. (2014) 10: 725
News and View by PL Luigi: Prebiotic metabolic networks?
http://msb.embopress.org/content/10/4/729, Mol Syst Biol. (2014) 10: 729
Sheyna E. Gifford for NASA in Astrobiology magazine., "Life’s Engine: The Early Ocean" http://www.astrobio.net/exclusive/6143/life%E2%80%99s-engine-the-early-ocean
Linda Geddes it the New Scientist, 'Spark of life: Metabolism appears in lab without cells'