2. run-off absorption decomposition Cycling of Matter transpiration The water cycle

3. fossil fuels The carbon cycle CO 2 + H 2 O C 6 H 12 O 6 + O 2 Photo Cell Resp Cycling of Matter

4. 1.Producers convert CO 2 into glucose to store the sun’s energy – photosynthesis. Plants change glucose into other organic carbon compounds. (proteins, fats, carbohydrates) 2. Consumers eat producers - carbon compounds are digested back to glucose. Cellular respiration is used to break down the glucose for energy, releasing CO 2. 4 steps of the Carbon Cycle:

5. 3. Decomposers break dead plants and animals down and release CO 2 and other simple molecules. Some decaying matter builds up in the earth, where is becomes fossil fuels. 4. Fossil fuels (oil, coal, natural gas) are burned by humans for energy. This combustion of fossil fuels releases CO 2 into the air.

6. Increases the amount of CO 2 in atmosphere:  Forest fires  Volcanoes  Deforestation  Combustion of fossil fuels Disturbing the Carbon Cycle: Decreases the amount of CO 2 in atmosphere:  Tree planting  Recycling  Use energy-efficient products  Ride a bicycle everywhere

7. Atmosphere (air) is 78% nitrogen gas (N 2 ). Most living things CANNOT use it in this form. 1. Nitrogen Fixation Bacteria change N 2 into compounds plants CAN use to make proteins – nitrate (NO 3 ) and ammonia (NH 3 ). These bacteria are found in soil near the roots of plants called legumes – peas, beans, peanuts. N2N2 NO 3 NH 3

8. Decomposers breakdown proteins into nitrate and ammonia to be used by NEW plants to grow. 2. Denitrification Different bacteria convert nitrate and ammonia from plant and animal waste back into nitrogen gas. When consumers eat, they convert plant protein into animal protein. N2N2 NO 3 NH 3

9. N2N2 N2N2 Cycling of Matter denitrification N2N2 nitrogen fixation N2N2 Nitrogen Cycle NH 3 NO 3 NH 3 legumes

10. Water containing excess NO 3, NH 3 have frequent algae problems (blooms) that produce dangerous toxins. Ammonia and nitrates seep into the ground water. Agriculture (farming) – (NO 3,NH 3 ) – pollutes water.  animal manure  excessive fertilizers on crops  ORGANIC FARMING Disturbing the Nitrogen Cycle Vehicle exhaust – (HNO 3 ) – causes acid rain.