Nitrogen Fixation

Nitrogen fixation is the process by which atmospheric nitrogen gas is converted into ammonia. The ammonia is subsequently available for many important biological molecules such as amino acids, proteins, vitamins, and nucleic acids. The reaction can be presented as follows:

N2 + 16 ATP + 8e- + 8H+ => 2NH3 + 16 ADP + 16 Pi + H2

This web site is not designed to be a comprehensive presentation on nitrogen fixation, but rather it is intended as a forum to present informative images that are not otherwise easily available. Persons wishing to contribute additional figures they consider particularly illustrative can contact me at

Part I. The range of organisms that can fix nitrogen

Part II. Physiology and anatomy of nitrogen fixation

Part III. Ecology of nitrogen fixation

This page is maintained by David Dalton, a faculty member in the Biology Department at Reed College.

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Created: July 31, 1997. Last modified: August, 21, 2007.
Copyright ©2007 David Dalton