Your lab uses the facultative anaerobe E. coli K-12 strain MG1655 as its model organism.  You have been asked to study some of the enzymes involved in aerobic respiration.

    1. Both succinate dehydrogenase and NADH dehydrogenase I (NDH-1) transfer electrons from their oxidized substrate to the ubiquinone pool.  Name two of the main possible terminal reductases that can receive the electrons and the environmental condition(s) that has to be present for each reductase.

 

 

    1. Name the substrate(s) and product(s) for each terminal reductase.

 

 

  1. Name the regulatory proteins that control expression of the succinate dehydrogenase operon; which of these regulators ensure optimal expression of the operon under aerobic conditions?