For every related student of medicine health sciences.

1. Nitrogen cycle
Presentation of Microbiology
Shafiq u Rahman
Biochemistry Bs 4th
University of Turbat

2. Table of Content
• Nitrogen fixation
• Ammonification
• Nitrification
• Assimilation
• Denitrification

3. Introduction
• Nitrogen is an important component of DNA,
RNA and protein, an important component of
life.
• All organisms require nitrogen to live and grow.
• The majority 78% of the earth’s atmosphere is
N2.

4. How can we use nitrogen
• In order for plants and animals to be able to use
nitrogen. N2 gas must be first converted to more
a chemically available form such as ammonia
(NH3) and nitrate (NO3-).
• It is possible through nitrogen cycle.

5. Nitrogen cycle
• The nitrogen cycle is the process by which
nitrogen is converted between its various
chemical forms. This transformation is carried
out through both biological and physical
processes.

6. Steps in nitrogen cycle
• Nitrogen fixation
• Ammonification
• Nitrification
• Assimilation
• Denitrification

7. Nitrogen fixation
• Fix of nitrogen is called fixation.
• It is done by thunderstorm.
• It is done by biological process.
• It is also done by industries.

8. Ammonification
• Living organisms contain nucleic acid and
protein they are decay by microbes, then release
ammonia and ammonium ions, this process is
called ammonification.
• Removing of ammonia and ammonium ion from
amino acid.

9. Nitrification
• Nitrification is the process that convert
ammonia to nitrite and then to nitrate .
NH3 NH4 Nitrosomonas Nitrite
Nitrite Nitrobacter Nitrate

10. Assimilation
• Absorb and utilize of nitrate by plants and
formation of nucleic acid and protein .
• This process is called assimilation.

11. Denitrification
• The removal of nitrogen again from nitrate in
plants.
• This process is called denitrification.

12. Biological process of nitrogen cycle