(i) The enzyme nitrogenase in root nodules of legume plants catalyses the conversion of atmospheric N2 to ammonia (NH3).
N2(Nitrogen) + 8e- + 8H+ + 16ATP → 2NH3(Ammonia) + H2 + 16ADP + 16Pi
(ii) Leghaemoglobin is an oxygen scavenger. It protects nitrogenase from oxygen.