Abstract The development of the complicated mechanisms for $ N_{2} $ fixation, which in nature is an endergonic process and requires a great deal of ATP, must have taken a long time. During that time primeval $ NH_{3} $ must still, albeit to a decreasing extent, have been available as a source of nitrogen. This is true, whether $ N_{2} $ fixation originally arose in the primitive anaerobes, or, according to Postgate, in more advanced bacteria. As $ NH_{3} $ resists UV radiation only in the presence of excess $ H_{2} $ it follows that the disappearance of $ H_{2} $ and the transition from the reducing to the neutral biosphere also took a long time, probably of the order of $ 10^{9} $ yr. According to previous evidence, the transition from the neutral to the oxidizing biosphere likewise took long; this length enabled the organisms to adapt the $ N_{2} $ fixing machinery to aerobic conditions.
The length of the transition period from the reducing to the neutral biosphere
Origins of life ; 8 , 2
1977
Aufsatz (Zeitschrift)
Englisch
Lokalklassifikation TIB: | 535/3908/4290 | |
BKL: | 44.71 Verkehrsmedizin |
NTIS | 1976
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