The Chemical Origin of Life

abiogenic synthesis actualistic aerobic algae amino acids anaerobic aqueous solution arisen atmosphere basis biochemical biological carbon compounds carbonaceous chondrites catalytic chain chemical coacervate droplets comets complicated composition concentration considerable contemporary organisms cosmic course crust earliest organisms Earth electron environment enzymes evolution of organic evolutionary existence external medium formation formed free oxygen further evolution galaxy gases geological gum arabic heavenly bodies heavy elements heterotrophic hydrocarbons hydrogen sulphide hydrosphere increase individual inorganic isotopes large number light living things material mechanisms ment metabolism meteorites microscope model experiments molecular molecules mononucleotide natural selection nucleic acids obtained occur Oparin organic compounds organic substances organisation origin oxidation oxido-reductive oxygen particular period photosynthesis planet polymerisation polymers polynucleotides polypeptides porphyrins possible pre-actualistic present primaeval broth primaeval nutrient broth prolonged evolution protein protobionts pyruvate radioactive reactions reducing residues Riphean Schramm stage stars structure surface surrounding medium tion took place transformations ultraviolet whole