Nitrogen cycle, Biology

Nitrogen is very important constituents of all organisms life  because it forms the structural parth of proteins, nucleic acids and chlorophyll molecules.

              Earth 's atmosphere contains 79% of N2   but it can not be used by living organisms.it has to be combined with other elements (C,H Or O) to make it into usable form. Thus, nitrogen cycle is the  biogeochemical cycle that describe the cycle flow of nitrogen and nitrogen containing compound in nature . it includes:

 

1.Fixation of Nitrogen in biosphere:

              Three processes are invole for nitrogen fixation:

(i)     Atmospheric fixation: combination of N2 and O2 into nitrogen oxide(NO,NO2, NO3)  in presence of thunder lightening. These nitrogen oxide dissolve in rain forming nitrate.

(ii)     Industrial fixation:  combination of N2 and H2 in presence of   cstalyst  and high pressure and  temperatures into NH3, which  is used for making  urea and ammonium nitrate (fertilizer.)

 

(iii)    Biological fixation:  involves conversion of N2 of air directly into organic nitrogen by  symbiotic (present in leguminous plants) bacteria or some by free living bacteria.

 

Rhizobium bacteria

(a)   N2 (air)      690_food chain.png        NO2   and  NO3     

                   (Root modulus of peas/beans)  

 

 

                              Azotobacters bacteria                                  

1517_nitrogen cycle1.png

 

Plants utilize this NO3 ions for their growth and multiplication.

 

2.       Nitrogen release into atmosphere:

      Nitrogen cycle is completed by release of N2 back into atmosphere. Certain bacteria(pseudomonas and clostridium) in soil carry out denitrification process and convert nitrate back into nitrogen gas.

  By anaerobic oxidation process, nitrate and ammonia are directly converted into gas.

Posted Date: 7/11/2012 7:16:58 AM | Location : United States







Related Discussions:- Nitrogen cycle, Assignment Help, Ask Question on Nitrogen cycle, Get Answer, Expert's Help, Nitrogen cycle Discussions

Write discussion on Nitrogen cycle
Your posts are moderated
Related Questions
5. Maple syrup urine disease is a rare inborn error of metabolism. It derives its name from the odor of the urine of affected individuals. If untreated, affected children die soon

Explain some Feeding Considerations or Nutrition Support? The preferred route for feeding the patient should be oral intake1 via the utilization of gastrointestinal tract. If o

Mention where the following are located in the human brain, and give single function of each: a) Temporal lobe b) Cerebellum c) Corpus callosum

What is the difference among essential and natural amino acids? Essential amino acids are those that the organism is not able to synthesize and that require to be ingested by t

Autotrophic and Heterotrophic Succession The succession where initially the green plants are much greater in quantity than the animals, is known as autotrophic succession. Su

Systemic embolization occurs in 22 per cent to 50 per cent of cases of IE. Emboli often involve major arterial beds, including lungs, coronary arteries, spleen, bowel, and extremit

Define Influence of Gardening on the Development of Botany? The influence of gardening on the development of botany may be seen in the work of John Gerard (1545-1612). Gerard p

Syngamy - Protozoan The two gametes may be morphologically similar (isogametes) or dissimilar (anisogametes). The gametes also vary in form, they may be flagellated or amoeboi

A plant grown from one of Mendel's yellow pea is selfed. Three progeny peas from this are obtained and they are all green. Is the original plant homozygous or heterozygous, and wha

State the term - Migraine Stroke Since the late 1800s, physicians have recognised that migraine attacks may lead to infarcts and permanent neurological deficits. Such migraine