Biology Forum › Ecology › what is mean by: oxygen has been quenched in the context
September 25, 2022 at 11:05 pm #219287Noha AbdelrazikParticipant
I am translating a book called Microbiology : a very short introduction. and I need to know what is meant by saying oxygen has been quenched in the following context and the overall idea of this paragraph:
The nature of the first cells is a subject of enthusiastic conjecture in the absence of objective data beyond the evident presence of life today.
The relative timing of the origin of archaea and bacteria is unknown, but fossils show that filamentous prokaryotes resembling today’s cyanobacteria had evolved at least 3.5 billion years ago.
It is possible that these microbes performed oxygenic photosynthesis, but measurements of radioactive isotopes show that the sharp rise in atmospheric oxygen known as the Great Oxygenation Event (GOE) did not occur until 2.3 billion years ago.
The putative billion-year discrepancy between oxygenic photosynthesis and the oxygenation of the atmosphere may be explained by the transformation of the planet’s highly reduced marine chemistry to a more oxidized state.
Oxygen released by photosynthesis would have been quenched by reacting with elements in their reduced forms for hundreds of millions of years after the evolution of cyanobacteria.
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