第二條al bio 問題

There are several points for the removal of nitrogen for the atmosphere.
(1)Plants absorb NO3- form the soil and then make protein.
(2)Herbivores eat the plant which becomes their body tissue.
(3)Nitrogen fixation carried out by nitrogen fixing bacteria found in root node of the leguminous plant converts nitrogen into Nitrate and ammonium cpds.
(4)nitrification by nitrite bacteria converts N2 to NO2- and nitrate bacteria
converts NO2- to NO3-.
(5)the haber process used in making fertilizer by using catalyst Fe N2 + 3H2 --> 2NH3
(6)putrefying bacteria decompose the dead organic matters and the excretory products from animals and then become NO3- and NH4+cpd
(7)lightning (閃電 ) breaks the triple bonds of the nitrogen and then forms nitric acid by the followings reactions
(a) N2 + O2 ----> 2N0 (energy provided by lightning)
(b)2NO +O2 ----> 2NO2
(c)2NO2 + H20 ----> HNO2+ HNO3

cpd = compound

For plants, they use them to make protein since some of the proteins can be made by themselves while some can't.
For animals, such as herbivores, they digest the plants and then release energy (ATP), for them to grow.

Removal of NO3-
just by the denitrifying bacteria breaking down nitrate and nitrite to N2 again.


The above answers just come from my memory and you can find them in YK TO's ecolgy book. If I am right, there are still 2 more I can't remember.