1. Ecosystem Cycles: Carbon Part 2

2. The Carbon Cycle 1. Every organic molecule contains the element carbon. A. Carbon and oxygen form carbon dioxide gas (CO 2 ), an important component of the atmosphere. B. Carbon dioxide is taken in by plants during photosynthesis and is given off by plants and animals during cellular respiration. 2. Four main types of processes move carbon through its cycle: A. Biological processes, such as photosynthesis, cellular respiration, and decomposition, take up and release carbon and oxygen.

3. The Carbon Cycle B. Geochemical processes, such as erosion and volcanic activity, release carbon dioxide into the atmosphere and oceans. C. Mixed biogeochemical processes, such as the burial and decomposition of dead organisms and their conversion under pressure into coal and petroleum (fossil fuels), store carbon underground. D. Human activities, such as mining, cutting and burning forests, and burning fossil fuels, release carbon dioxide into the atmosphere.

4. Carbon Cycle http://www.youtube.com/watch?v=2D7hZpIYl CA http://www.youtube.com/watch?v=2D7hZpIYl CA

5. Ecosystem Cycles: Nitrogen Cycle Part 3

6. The Nitrogen Cycle 1. All organisms require nitrogen to make amino acids, which in turn are used to build proteins. A. Nitrogen gas makes up 78% of Earth’s atmosphere. B. Nitrogen containing substances that are found in the wastes produced by many organisms and in dead and decaying organic matter. C. Nitrate is major component of plant fertilizers.

7. The Nitrogen Cycle 2. Nitrogen gas is the most abundant form but only certain bacteria can use this form. A. Such bacteria live in the soil and on the roots of plants. B. These bacteria convert nitrogen gas into ammonium--nitrogen fixation. C. Other bacteria in the soil convert ammonia into nitrites and nitrates.

8. 3. Once the nitrites and nitrates are available, producers (plants) can use them to make proteins. Consumers then eat the producers and reuse the nitrogen to make their own proteins. 4.When organisms die, decomposers return nitrogen to the soil as ammonia. 5.Other soil bacteria convert nitrates into nitrogen gas--denitrification. This process releases nitrogen into the atmosphere once again.

9. Video http://www.youtube.com/watch?v=leHy- Y_8nRs http://www.youtube.com/watch?v=leHy- Y_8nRs

10. Research Question 1.What are the four main ways carbon is moved through the carbon cycle? 2.Illustrate the components of the carbon cycle. 3.Explain why we need nitrogen and where it is mostly found. 4.Illustrate the main components of the nitrogen cycle. 5.When people burn fossil fuels, carbon dioxide gas is added to the atmosphere. How might increased carbon dioxide affect plant growth? 6.What is denitrification and in what cycle is it in? 7.Does nitrogen get absorbed into our bodies when we breath it in? 8.How does carbon get out of the atmosphere? 9.How does nitrogen get out of the atmosphere?

11. CO 2 in Atmosphere Photosynthesis Cellular Respiration Decomposition of dead organisms Coal and Petroleum Burning of Fossil Fuels

12. Nitrogen Fixation Denitrification Decomposers return ammonia to soil Nitrogen Gas in Atmosphere Nitrites (NO 2 - ) Nitrates (NO 3 - )