The serine pathway and ribulose monophosphate pathway can both be used by ________ as a way to incorporate carbon into biomass.
A) acetogens
B) anoxygenic hydrocarbon fermenters
C) methanogens
D) methylotrophs
What products would be expected to form during anoxic degradation of the seven-carbon compound benzoate following reduction and cleavage of the aromatic ring?
A) 1 three-carbon compound and 1 four-carbon compound
B) 1 three-carbon compound and 2 two-carbon compounds
C) 2 three-carbon compounds and CO2
D) 3 two-carbon compounds and CO2
A researcher lacked the necessary equipment to measure methane production so instead monitored CO2 concentration as the unknown archaeon grew and produced methane. Why might CO2 NOT decrease but methane still increase?
A) An alternative carbon source such as methanol was used.
B) CO2 is not a carbon source used by methanogens.
C) CO2 was used an electron donor but not as a carbon substrate.
D) Methanogenic Archaea containing carboxysomes likely made measuring small losses of CO2 difficult to conclude.
How is ATP made by an acetogen during CO2 fixation?
A) Electrons from metal cofactors energize the electron transport chain and drive the proton motive force to activate ATP synthase.
B) Substrate-level phosphorylation of ADP occurs when coenzyme A is removed from acetyl-CoA.
C) It is made by substrate-level phosphorylation and a Na+-translocating ATPase.
D) The energized CO-CH3 complex during thioesterification drives a Na+-translocating ATPase.
Anaerobic fermentation often provides CO2, which can be used by ________ as an electron acceptor for energy.
A) acetogens
B) methanotrophs
C) methanogens
D) acetogens and methanogens
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