Empfohlen
Weitere ähnliche Inhalte
Was ist angesagt?
Was ist angesagt? (20)
Andere mochten auch
Andere mochten auch (12)
Ähnlich wie Nitrogen cycle
Ähnlich wie Nitrogen cycle (20)
Kürzlich hochgeladen
Kürzlich hochgeladen (20)
Nitrogen cycle
- 2. Nitro • an essential part of the amino acids. It is a basic element of life. Cyclegen n + es‘‘nitre forming’’ • composes about four-fifths (78.03 percent) by volume of the atmosphere. •in the form of protein is an important constituent of animal tissue. • is an important element in plant nutrition.•is inert and serves as a diluent for oxygen in burning and respiration processes.
- 3. Nitrogen Cycle • natural cyclic process in the course of which atmospheric nitrogen enters the soil and becomes part of living organisms
- 4. Importance of Nitrogen Cycle • essential to living organisms and its availability plays a crucial role in the organization and functioning of the world's ecosystems • key factor controlling the nature and diversity of plant life • vital ecological processes such as plant productivity and the cycling of carbon and soil minerals
- 5. Steps of Nitrogen Cycle • Nitrogen Fixation • Nitrogen Assimilation • Ammonification • Nitrification • Denitrification
- 6. Nitrogen Fixation • nitrogen gas is converted into inorganic nitrogen compounds. It is mostly (90 percent) accomplished by free-living, nitrogen-fixing bacteria.
- 7. Nitrogen-Fixing Bacteria • symbiotic bacteria living on the roots of plants (mostly legumes and alders) • cyanobacteria (formerly known as blue- green algae) • archaebacteria (also known as archaea) in deep-sea hydrothermal vents
- 8. Nitrogen Fixation by Haber-Bosch Process • method of directly synthesizing ammonia from hydrogen and nitrogen, developed by the German physical chemist Fritz Haber.
- 9. Nitrogen Fixation by Lightning • The high energies provided by lightning and cosmic radiation serve to combine atmospheric nitrogen and oxygen into nitrates, which are carried to the Earth’s surface in precipitation.
- 10. Steps of Nitrogen Cycle • Nitrogen Fixation • Nitrogen Assimilation • Ammonification • Nitrification • Denitrification
- 11. Nitrogen Assimilation • are assimilation of nitrates and ammonia resulting from nitrogen fixation into the specific tissue compounds of algae and higher plants. Animals then ingest these algae and plants, converting them into their own body compounds.
- 12. Steps of Nitrogen Cycle • Nitrogen Fixation • Nitrogen Assimilation • Ammonification • Nitrification • Denitrification
- 13. Ammonification • The remains of all living things—and their waste products—are decomposed by microorganisms which yields ammonia.
- 14. Steps of Nitrogen Cycle • Nitrogen Fixation • Nitrogen Assimilation • Ammonification • Nitrification • Denitrification
- 15. Nitrification • a process carried out by nitrifying bacteria, transforms soil ammonia into nitrates, which plants can incorporate into their own tissues.
- 16. Steps of Nitrogen Cycle • Nitrogen Fixation • Nitrogen Assimilation • Ammonification • Nitrification • Denitrification
- 17. Denitrification • The process where nitrates are metabolized by denitrifying bacteria to free nitrogen and returned to the atmosphere
- 18. Human Intrusion and Its Effects Declination of nitrogen in the soil • cultivation of croplands • harvesting of crops • cutting of forests
- 19. Human Intrusion and Its Effects Over supply of Nitrogen • the production and use of nitrogen fertilizers • burning of fossil fuels in automobiles, power generation plants, and industries
- 20. Human Intrusion and Its Effects Over supply of Nitrogen • the leaching of nitrogen from over fertilized croplands, • animal wastes and sewage
- 21. Effects of Over Supply of Nitrogen • substantial acidification of soils and of the waters of streams and lakes • acid rain • Increased global concentrations of nitrous oxide (N2O), a potent greenhouse gas,
- 22. Effects of Over Supply of Nitrogen • stratospheric ozone depletion • greatly increased transport of nitrogen by rivers into estuaries and coastal waters where it is a major pollutant.
- 23. References • http://www.bbc.co.uk/schools/gcsebitesize/science/21c/food/naturalp olymersrev3.shtml • http://www.epa.gov/owow/watershed/wacademy/acad2000/nitroabstr. html • Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved. • nitrogen cycle. (2010). In Encyclopædia Britannica. Retrieved September 02, 2010, from Encyclopædia Britannica Online: http://www.britannica.com/EBchecked/topic/416271/nitrogen- cycle • Haber-Bosch process. (2010). Encyclopædia Britannica. Encyclopaedia Britannica Ultimate Reference Suite. Chicago: Encyclopædia Britannica.