During N2 fixation, reduction of one molecule of nitrogen into 2 molecule of NH3 consumes ______ molecules of ATP. (a) 4 (b) 16 (c) 56 (d) 38
Option B.Two molecules of ammonia are produced from one molecule of nitrogen gas, at the expense of 16 units of ATP and a supply of electrons and hydrogen ions. N2 + 8H+ + 8e− + 16 ATP = 2NH3 + H2 + 16ADP + 16 Pi. During biological nitrogen fixation, 16 ATP are used. Iron and Molybdenum play important role in this. End product is ammonia and hydrogen.
