Anaerobes energy capture 226

H2 as a reductant (Fe, Ni) in anaerobic archaea Energy capture related to ATP formation (Fe, NADH, flavin, quinones)... 

To conclude this chemical account of the earliest prokaryotes, we can see that there were at least basically two similar anaerobic groups of organisms, archaea and bacteria, which have hardly changed till today in chemical composition, energy capture modes and space occupied but were improved in organisation by... 

Looking at Table 7.8 it is readily seen that in terms of fitness eukaryotes and prokaryotes each have advantages and disadvantages so that the best solution for total optimal energy capture is coexistence assisted by cooperation not competition. If life could have started from a situation where there had been an ample supply of sufficiently reduced basic small molecule materials and energy and no reduction but only molecular combination was required, it may well have been that anaerobic prokaryotes would have remained exclusively successful. They are still in abundance on the Earth. There would have been no need to reject oxidised materials, and increase in the number of compartments would have had little advantage since the observed chemically necessary syntheses (see Chapter 4) are simply... 

Anaerobic. Moisture is added to the waste mass in the form of recirculated leachate and from other sources to obtain optimal moisture levels. Biodegradation occurs in the absence of oxygen (anaerobically) and produces landfill gas. Landfill gas, primarily methane, can be captured to minimize greenhouse gas emissions and for energy projects. 

The estimated values for the efficiency of biomass production vary appreciably, for both aerobes and anaerobes. Some species are efficient in capturing the energy in the organic substrate and converting the carbon to cells, but others are notably inefficient. 

During glycolysis, glucose is converted to two molecules of pyruvate. A small amount of energy is captured in two molecules each of ATP and NADH. In anaerobic organisms, pyruvate is converted to waste products in a process called fermentation. In the presence of oxygen the cells of aerobic organisms convert pyruvate into CO, and H20. 

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