|
|
Article: Nitrogen Fixation
- Article from:
- Plant Sciences
- Author:
CopyrightCOPYRIGHT 2001 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
|
Nitrogen Fixation
Biological nitrogen (N
2
) fixation is the reduction of atmospheric nitrogen gas to ammonia, according to the equation:
N
2
+ 10H
+
8
e
-
16ATP
+
2NH
4
+
+ H
2
+ 16ADP + 16P
i
The reaction is mediated by an oxygen-sensitive
enzyme
nitrogenase and requires energy, as indicated by the consumption of adenosine triphosphate (
ATP
). This conversion of
inert
N
2
gas into a form utilized by most organisms is the second most important biological process on Earth after photosynthesis. It contributes 175 million tons of nitrogen per year to the global nitrogen economy and accounts for 65 percent of the nitrogen used in agriculture. In Brazil alone, N
2
fixation contributes the ...