1. 1.2 Nutrient Cycles and Energy Flow (Part 1) pp. 22 - 29

2. Learning Goals By the end of this lesson, you should: ◦ Know the steps of the following cycles: water, nitrogen, carbon. ◦ Know the equations for photosynthesis and cellular respiration, and where these processes take place (plants / animals) ◦ Understand why each cycle is important to a healthy ecosystem

3. Nutrient Cycles Nutrient – Substances that an organism uses to build and repair cells in the body. In a cycle there is no beginning or end. Nutrients cycle back and forth between the biotic and abiotic parts of ecosystems. Water, carbon and nitrogen are nutrients that all have reservoirs. ◦ A reservoir is a place where matter accumulates / is stored

4. The Water Cycle The sun warms the surface water, and the water evaporates into the atmosphere. The water vapour cools and condenses to form clouds. Water falling from the clouds to the ground is called precipitation Water that runs from the ground into streams or rivers is called run-off.

5. The Water Cycle Some water seeps through the soil and into ground water. Large underground lakes are known as aquifers. Plants absorb some of the water in the ground and release it through their leaves in a process known as transpiration The water vapour rises and the cycle continues.

6. Condensation Precipitation Surface Run-Off Percolation Filtering of H 2 O downward through soil Transpiration Respiration Evaporation

7. The Nitrogen Cycle All organisms need nitrogen to make proteins 78 % of the atmosphere is nitrogen but it cannot be directly used by organisms. Organisms get nitrogen from substances that contain nitrogen.

8. The Nitrogen Cycle The act of converting nitrogen gas (N 2 ) to ammonia is called Nitrogen fixation Nitrogen fixing bacteria perform this critical step ◦ Without the bacteria the cycle would stop ◦ Lightning only fixates 1% of the world’s nitrogen Most plants cannot use the ammonia created

9. The Nitrogen Cycle Nitrifying bacteria convert the ammonia into nitrates Nitrates are absorbed and used by the plants Animals eat plants to obtain nitrogen. The animals then produce ammonia which is removed as waste. Nitrifying bacteria then convert the ammonia to nitrates. Denitrifying bacteria in the soil convert nitrates back into nitrogen gas.

10. 1.Nitrogen gas (N 2 ) in Atmosphere 2.Nitrogen-fixing Bacteria 3.Fertilizers (already nitrates) 4.Soil Nitrates Accumulate 5.Uptake of Nitrates by plant roots 6. Nitrates move along food chain 7. Dead Organisms 8 -10 Nitrifying Bacteria 11. Denitrifying Bacteria 12. Fixation by Lightning 12. Nitrogen Fixation by Lightning

11. The Carbon Cycle (2 parts) 1. Photosynthesis 2. Cellular respiration All living things contain carbon Plants obtain carbon from the atmosphere ◦ Forests are carbon reservoirs as well as coal and oil deposits Oceans are also reservoirs for carbon dioxide

12. 1. Photosynthesis The process that plants use to capture energy from sunlight Plants use chlorophyll to combine carbon dioxide from the air (CO 2 ) and water (H­ 2 O) to produce a sugar called glucose (C 6 H 12 O 6 ) and oxygen gas (O 2 ) Summary Carbon dioxide gas + water + sunlight  glucose + oxygen gas CO 2 + H 2 O + sunlight  C 6 H 12 O 6 + O 2

13. Make a simple drawing of this

14. 2. Cellular Respiration The process both plants and animals use to turn glucose into energy. The process is almost the reverse of photosynthesis Summary Glucose + Oxygen gas  Carbon dioxide + Water + energy C 6 H 12 O 6 + O 2  CO 2 + H 2 O + energy Photosynthesis + Cellular Respiration = Carbon Cycle

15. 1.Carbon dioxide (CO 2 ) gas 2.CO 2 absorbed during photosynthesis 3.Carbon moves along food chain 4.CO 2 returned during cellular respiration 5. Plants turn into fossil fuels (takes time and extreme heat and pressure) 6. CO 2 returned by burning fossil fuels 7. CO 2 returned during cellular respiration

16. Learning Goals By the end of this lesson, you should: ◦ Know the steps of the following cycles: water, nitrogen, carbon. ◦ Know the equations for photosynthesis and cellular respiration, and where these processes take place (plants / animals) ◦ Understand why each cycle is important to a healthy ecosystem

17. Homework Read 22-29 Answer the following Questions: ◦ p. 27 # 1, 3, 4 ◦ p. 35 # 2, 4 – 6, 12, 14