Sentences with phrase «o2 by photosynthesis»

Micro-organisms were certainly present before 3.0 billion years ago but they were not likely capable of producing O2 by photosynthesis.

Not exact matches

Not so much by direct photolysis of water vapor (not generally a lot of that in the stratosphere), but from CH4, which could build up in a nearly oxygen - free atmosphere, and being largerly of biotic origin, with the H coming from photosynthesis (releasing O); O2 buildup itself was delayed because of geologic O2 sinks (in particular, the conversion of ferrous Fe (naturally present in the crust and mantle and which can dissolve in the oceans) to ferric Fe (precipitates out of the water, the source of banded - iron formations, which humans have used to get Fe).

Photosynthesis: H2O + CO2 = (CH2O) n + O2, so aside from oxidizing ferrous iron or..., moles of O2 would increase by the same amount that moles of organic C would increase.