1. The Carbon Cycle 4 kinds of processes involved in the carbon cycle Geochemical – volcanoes releasing carbon – Biological processes – photosynthesis, respiration, and decomposition of plants and animals – Biogeochemical – burial of remains and conversion into fossil fuels – Human activity – including mining, the burning of fossil fuels, and the cutting and burning of forests

2. The Carbon Cycle In the atmosphere, carbon is present as carbon dioxide. This carbon dioxide came from – Volcanic activity – Respiration – Burning of fossil fuels – Decomposition of organic matter CO 2

3. Why is there a 6 in front of all molecules but sugar?

4. Where do you think CO 2 And O 2 go?

5. What is the most common gas in the atmosphere?

6. The Nitrogen Cycle Nitrogen required to make amino acids, which are used to build proteins. When organisms die, decomposers return nitrogen to the soil as ammonia N2N2 NH 3 NO 3 - NO 2 -

7. The Nitrogen Cycle nitrogen gas (N 2 ) makes up 78% of atmosphere N2N2 NH 3 NO 3 - NO 2 -

8. The Nitrogen Cycle Ammonia (NH 3 ), nitrate ions (NO 3 -), and nitrite ions(NO 2 -) are found in wastes produced by organisms These compounds taken up by producers to make proteins N2N2 NH 3 NO 3 - NO 2 -

9. The Phosphorous Cycle Important to living organisms because it forms part of DNA and RNA Not very common in biosphere

10. The Phosphorous Cycle Important to living organisms because it forms part of DNA and RNA Not very common in biosphere Does not enter atmosphere – Instead it remains mostly on land in rock and soil minerals, and in ocean sediments

11. Nutrient Limitation Limiting nutrient – single nutrient that either is scarce or cycles very slowly, limiting the growth of organisms in an ecosystem – Examples – farmers add fertilizers that contain nitrogen, phosphorus, and potassium to their crops

12. Algal bloom – immediate increase in the amount of algae and other producers that results from a large input of a limiting nutrient