The enzyme nitrogenase is a $....................$.

Crop rotation is helpful because

Which enzyme is involved in nitrogen metabolism?

The enzyme responsible for atmospheric nitrogen fixation is

$A-$ The microbe $Frankia$ produces nitrogen-fixing nodules on the roots of non-leguminous plants.
$R-$ Both $Rhizobium$ and $Frankia$ are free-living in soil,but as symbionts,can fix atmospheric nitrogen.

Complete the given reaction:
$N_2 + 8e^- + 8H^+ + 16 \,ATP \rightarrow$