Amino acid nitrogens were originally converted from N2 into NH4+ by nitrogen fixing bacteria or algae. The N2 bond is very stable, 946kL/mol. Industrial nitrogen fixation is carried out a extremely high pressure (N2 + 3 H2 reacts to form 2 NH3), the high pressure, by LeChatelier's principle, driving the reaction forward. Both ATP and a powerful reductant are required for the biological reduction of N2 in nitrogen fixation.