Electron Flow In Organotrophy Lithotrophy And Phototrophy - Microbiology An Evolving Science

In a redox reaction, the reduction potential E depends on the ratio of product concentrations ([C] and [D]) to reactant concentrations ([A] and [B]), as per equation E = E°' - 60 (mV/n) log [C][D]/[A][B]. What would be the effect of increasing the ratio of products to reactants by a factor of 10?

A) No effect: E°' assumes 1-M concentrations of reactants and products.
B) A change of -60 mV will not modify the estimate of E.
C) The value of E will decrease by 60 mV, decreasing energy yield.
D) The value of E will increase by 60 mV, increasing energy yield.
E) The E°' term is unaffected by changes in concentrations of products or reactants.

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Question 2

(Multiple Choice)

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How are drug efflux pumps spread among virulent bacterial strains?

A) They are spread through generalized transduction.
B) Their genes are contained in plasmids that are transmitted among bacterial cells.
C) They are spread through conjugation between two virulent strains.
D) They are spread through transformation with Hfr plasmids.
E) DNA is released from bacterial cells previously infected with bacteriophages.

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Question 3

(Multiple Choice)

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Which of the following is FALSE regarding the ETS in Escherichia coli?

A) NDH-1 is the main initial substrate oxydoreductase; NDH-2 is an alternative NADH dehydrogenase.
B) It pumps 10-12 protons per NADH.
C) It pumps 2-8 protons per NADH.
D) The main terminal oxidase is the cytochrome bo quinol oxidase, which contains heme b, heme O₃, and Cu.
E) An alternative cytochrome bd quinol oxidase has a higher affinity for oxygen than other terminal oxidases and allows E. coli growth in low-O₂ habitats.

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