. . . . . . . . . . . . . . . . . . . . . . "15272963"^^ . . . . . . . . . . . . . . . . . . . . . . . . . . . . "1105431787"^^ . . . . "11189"^^ . . . . . . . "Dioxygen (O2) plays an important role in the energy metabolism of living organisms. Free oxygen is produced in the biosphere through photolysis (light-driven oxidation and splitting) of water during photosynthesis in cyanobacteria, green algae, and plants. During oxidative phosphorylation in cellular respiration, oxygen is reduced to water, thus closing the biological water-oxygen redox cycle."@en . . . . . . . . . . . . . . . . . . . . . . "Dioxygen in biological reactions"@en . . . . . . . "Dioxygen (O2) plays an important role in the energy metabolism of living organisms. Free oxygen is produced in the biosphere through photolysis (light-driven oxidation and splitting) of water during photosynthesis in cyanobacteria, green algae, and plants. During oxidative phosphorylation in cellular respiration, oxygen is reduced to water, thus closing the biological water-oxygen redox cycle."@en . . . . . . . . . . . . . . . . . . . .