Aerobic Respiration - Exercise #1

You are studying two different terminal oxidases found in the facultative anaerobe E. coli K-12 strain MG1655: cytochrome bo oxidase and cytochrome bd-I oxidase. 

  1. Write out the full, complete enzymatic reaction(s) these oxidases carry out. 


  3. In addition, you note that the E.C. # for cytochrome bd-1 terminal oxidase differs from that of the cytochrome bo terminal oxidase.  What other enzyme carries out the same enzymatic reaction as cytochrome bd-1 terminal oxidase?


  5. Your colleague in the lab across from you is studying the role of Actinomyces in dental plaque, a microaerophilic environment.  She wishes to perform a gene knockout of the oxidase most likely to be involved in respiration during low oxygen concentrations, but doesn’t know which genes she should start with.  Knowing that E. coli can survive in microaerophilic conditions through the use of one its oxidases, you suggest she knock out the Actinomyces oxidase most similar to which E. coli oxidase?