1. NITROGEN CYCLE

2. Nitro Composes about four-fifths (78.03 percent) by volume of the atmosphere an essential part of the amino acids. It is a basic element of life. is an important element in plant nutrition in the form of protein is an important constituent of animal tissue. Cycle gen

3. Nitrogen Cycle natural cyclic process in the course of which atmospheric nitrogen enters the soil and becomes part of living organisms

4. Nitrogen Cycle

5. Amounts of Nitrogen Nitrogen ReservoirMetric tons nitrogen Atmosphere3.9*10 15 Land  organic matter  Biota 1.1*10 11 2.5*10 10 Ocean  soluble salts Biomass 6.9*10 11 5.2*10 8

6. Forms of Nitrogen in Ocean FormFormulaFunctionPathwayHabitat NitrateNO 3 _ Electron acceptor, nitrogen source Nitrogen assimilation, dissimilatory nitrate reduction and denitrification Coastal upwelling zones, deep ocean Ammonium NH 4 + Electron donor, energy source, nitrogen source Nitrogen assimilation, ammonia oxidation (aerobic), and anaerobic ammonia oxidation Important, rapidly recycled pool in open ocean, intermediate in decomposition of organic matter Nitrite NO 2 - Electron donor and acceptor, energy source, nitrogen source Nitrification (nitrite oxidation), denitrification Found at margins of oxic/anoxic regions, intermediate in oxidation and reduction pathways DinitrogenN2N2 Nitrogen source_______High concentration in equilibrium with atmosphere, available to N2-fixing microorganisms Nitrous oxideN2ON2OTrace gas, electron acceptor, electron donor End or by-product of nitrification and denitrification Intermediate in reductive pathway, also formed in nitrification and at oxic/anoxic interfaces and anoxic or suboxic zones UreaCH 4 N 2 ONitrogen sourceNitrogen assimilationDecomposition product, potentially important nitrogen source in water column

7. Steps of Nitrogen Cycle Nitrogen Fixation Nitrogen Assimilation Ammonification Nitrification Denitrification

8. Nitrogen Fixation Nitrogen gas is converted into inorganic nitrogen compounds. It is mostly (90 percent) accomplished by free-living, nitrogen-fixing bacteria.

9. 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

10. 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.

11. Steps of Nitrogen Cycle Nitrogen Fixation Nitrogen Assimilation Ammonification Nitrification Denitrification

12. 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.

13. Steps of Nitrogen Cycle Nitrogen Fixation Nitrogen Assimilation Ammonification Nitrification Denitrification

14. Ammonification The remains of all living things—and their waste products—are decomposed by microorganisms which yields ammonia.

15. Steps of Nitrogen Cycle Nitrogen Fixation Nitrogen Assimilation Ammonification Nitrification Denitrification

16. Nitrification a process carried out by nitrifying bacteria, transforms soil ammonia into nitrates, which plants can incorporate into their own tissues. 1 rst step catalyzed by Nitrosomonas 2 NH 4 + + 3 O 2  2 NO 2 - +2 H 2 O+ 4 H + 2 nd step catalyzed by Nitrobacter 2 NO 2 - + O 2  2 NO 3 -

17. Steps of Nitrogen Cycle Nitrogen Fixation Nitrogen Assimilation Ammonification Nitrification Denitrification

18. Denitrification The process where nitrates are metabolized by denitrifying bacteria to free nitrogen and returned to the atmosphere

19. Nitrogen Cycle in Ocean In groups construct a poster or drawing diagram about how the Nitrogen Cycle would work in the ocean Label steps ( Nitrogen Fixation, Nitrogen Assimilation, Ammonification, Nitrification, Denitrification)

20. Nitrogen Cycle In Ocean

21. Nitrogen Cycle in Fish Tanks