1. TUESDAY 1/20/2015 Agenda: Nitrogen Cycle Biogeochemical Cycles  Activity: Nitrogen Cycle Reading and Questions NOTEBOOK CHECKS TOMORROW!! Homework/Classwork Nitrogen Reading and Annotations due TODAY 1/20/2015 for 30 points

2. The nitrogen cycle packet! Read and annotate EACH SENTENCE IN THE ARTICLE!!! Fill in the diagram with the correct diagram statements Answer the questions in complete sentences This is due TODAY FOR 30 POINTS!!!

3. Wednesday/Thursday 1/21- 1/22/2015 Agenda: Nitrogen Cycle Biogeochemical Cycles  Notes: Nitrogen Cycle  Activity: Nitrogen Cycle Reading Assignment Homework/Classwork Nitrogen Reading Assignment due Wednesday/Thursday 1/21-1/22/20115 for 30 Points

4. The Nitrogen Cycle  Nitrogen is an important nutrient in the ecosystem  Used to make organic molecules: amino acids, proteins, DNA  The nitrogen cycle is the process by which atmospheric nitrogen is converted to ammonia (NH 3 ) or nitrates (NO 3 ).  Moves slowly through the cycle  Nitrogen is essential to all living systems, but most nitrogen is found in the atmosphere, so…  for an organism to be able to use it, nitrogen must first be combined (“fixed”) with hydrogen (H) or oxygen (O).  This process is called nitrogen fixation.

5. Nitrogen Sinks/Reservoirs Where is nitrogen stored or retained? Animals and their waste Atmosphere Decomposers (bacteria and fungi) in soil and plants Plants Soil Water Main sink/reservoir is the atmosphere Gas = N 2 (di nitrogen ) ~80%

6. The Nitrogen Cycle Continued  Nitrogen is removed from the atmosphere by:  lightning and  nitrogen -fixing bacteria.  Lightning storms – cause large amounts of di nitrogen ( N 2 ) to be broken apart, combined with oxygen (NO 3 ) and dissolved in rain water…  Produces an acid that falls to the earth in rain – Nitrates  Nitrates are taken up by plants and made into proteins to make plant tissue.

7. The Nitrogen Cycle Continued How do animals get nitrogen ? Nitrogen passes through the food chain Animals consume plants or other animals that contain organic molecules composed partially of nitrogen Nitrogen is then put back into soil as waste or when an organism dies. This is called mineralization.

8. The Nitrogen Cycle Continued  How do animals get nitrogen ?  Decomposers in the soil break down the waste/decay  After the nitrogen compounds break down, ammonia (NH 3 ) is left.  This process is called ammonification.  The ammonia is then either  taken up by plants,  dissolved in water, or  held in soil where bacteria convert it to nitrates (NO 3 ).  This process is called nitrification.

9. The Nitrogen Cycle diagram