Nitrogen Fixation Flashcards
In nature: Lightening strikes -
Peak intensity can be
30’000 ‘C ; five times hotter than the surface of the sun.
In nature: Lightening strikes -
Accounts for about
10% of total annual natural nitrogen fixation.
In nature: Lightening strikes -
Results in extreme
Heating of atmospheric gases in pathway.
In nature: Lightening strikes -
Enough energy is absorbed by a
Dinitrogen molecule, N2, to split the triple bond and produce nitrogen atoms.
In nature: Lightening strikes -
The nitrogen atoms
Collide with oxygen atoms and molecules to produce nitric oxide, NO.
In nature: Lightening strikes -
Nitric oxide, NO, can
Combine with O2 to for nitrogen dioxide, NO2.
In nature: Lightening strikes -
NO and NO2 dissolve in rainwater to
Produce nitrus, HNO2, and nitric, HNO3, acid.
These become deposited by rain, dissociate and release NO2- and NO3- into ecosystems.
In nature: Lightening strikes -
NO2- ➡️ NO3- during
Biogeochemical cycling.
In nature: Nitrogen fixing organisms -
If nitrogen levels fall, non-fixing organisms will
Decline in direct proportion to the falling levels.
In nature: Nitrogen fixing organisms -
By
Bacteria and Cyanobacteria.
In nature: Nitrogen fixing organisms -
Will detect the fall in levels and
At a certain level, the nif genes are activated and organisms start to fix dinitrogen.
In nature: Nitrogen fixing organisms -
Rhizobium bacteria have a
Symbolic relationship with legumes.
By humans: Fertilizers -
50% of fertilizer can be lost from the soil as it is actively cycled in the soil
Before being assimilated by plants.
Results in the formation of soluble inorganic and gaseous forms of nitrogen.
By humans: Fertilizers -
Results in a reduction of
Plant diversity to a single crop, which may be incapable of fixing nitrogen.
By humans: Industrial -
Energy intensive;
Requires high temperatures and pressure, unlike natural fixation.
