Bacteria and archaea carry out the process of nitrogen fixation, which reduces atmospheric nitrogen, N,, to the biologically useful form NH,, also called ammonia. The nitrogenase complex consists of two proteins, reductase and nitrogenase, which catalyze the reactions of nitrogen fixation. Match each structural feature or function with the corresponding component of the nitrogenase complex. a. Reductase b. Nitrogenase1. homodimer 2. heterotetramer 3. also called the molybdenum-iron protein, or the MoFe protein 4. transfers electrons from a donor, such as ferredoxin, to the other component 5. binds and hydrolyzes ATP for electron transfer6. also called the iron protein, or the Fe protein 7. site of nitrogen fixation