1. NITROGEN CYCLE

2. What does this have to do with me?

3. Nitrogen Cycle The series of processes by which nitrogen and its compounds are exchanged between the environment and living organisms.

4. Two Purposes Helps to keep the environment clean Replenishes and balances the supply of nitrogen in the ecosystem

5. Why Do We Need Nitrogen? It is a necessary component of all proteins. It is necessary for the formation of nucleic acids. DNA ← Our atmosphere is about 78% nitrogen gas (N 2 ). Can’t we just breathe it in?

6. We Cannot Break the Bond in N 2 Atmospheric nitrogen (N 2 ) is a stable molecule and requires a lot of energy to break apart. Lightning Volcanic activity

7. Bacteria But the majority of the nitrogen used by living things is made available by...

8. Six Steps The steps of the nitrogen cycle are: 1. Nitrogen Fixation 2. Decomposition 3. Ammonification 4. Nitrification 5. Assimilation 6. Denitrification } Making Nitrogen Useable ← Using Nitrogen ← Getting Rid of Unused Nitrogen

10. Nitrogen Fixation This is a process where some soil bacteria convert atmospheric nitrogen (N 2 ) to ammonia (NH 3 ). These bacteria can either live free in the soil, or they can live inside the roots of some legumes.

11. Nitrogen Fixing Bacteria in Roots Legumes such as peas, beans, alfalfa, clover, and peanuts have many of these bacteria living in root nodules. Both the bacteria, and the plants benefit from this relationship. ← ←

12. Decomposition This is the process by which bacteria and fungi break down dead organic matter

13. Ammonification Bacteria and fungi turn nitrogen products of decomposition into ammonia (NH 3 ). Decomposed Organic Matter ← ↔ Ammonia (NH 3 ) Ammonium (NH 4 + )

14. Nitrification Nitrification is the conversion of ammonia (NH 3 ) to nitrite (NO 2 - ), and then to nitrate (NO 3 - ).The bacteria gain the energy that they need, and give off nitrate (NO 3 - ) as a waste product.

15. Assimilation Plants absorb ammonia (NH 3 ) and nitrate (NO 3 - ), and use them to build amino acids (building blocks of proteins), and nucleic acids. Animals eat plants and assimilate their nitrogen into more organic molecules

16. Denitrification N ot all fixed nitrogen is used by plants and animals. Some is converted back into nitrogen gas (N 2 ). S ome bacteria use nitrogen from Nitrate (NO 3 - ) for their cellular respiration instead of oxygen. Release nitrogen gas (N 2 ) as product Why do we need this step?

17. The Nitrogen Cycle Also Works Under Water The same processes also take place in aquatic ecosystems with nitrogen that is dissolved in water. Nitrogen Cycle in an Aquarium

18. Expanded Nitrogen Cycle

19. Haber Bosch Process Nitrogen fixation commercially for fertilizer production Uses a combination of Nitrogen Gas (N 2 ) and Hydrogen gas (H 2 ) under high temperatures and pressures in order to produce ammonia (NH 3 )

20. Scishow https://www.youtube.com/watch?v=tdEE5uvFhOM

21. To Make Plants Grow Better, These can include: Animal manure Plant compost Ammonia Commercially prepared nitrates “Chemical fertilizers” can disrupt fragile ecosystems. “Natural fertilizers” adds nutrients slowly through decomposition and ammonification. We Add Fertilizers