6 Nitrogen CycleAll organisms need nitrogen to make proteins and nucleic acidsNitrogen gas makes up 78% of the Earths atmosphereMost plants only use nitrates (NO3)
7 Nitrogen fixationThe process bacteria use to convert nitrogen gas (N2) to ammonia (NH3)The bacteria are known as nitrogen-fixing bacteriaThey live in the soil and inside swellings on the roots of some plants (beans, clover, etc)The plants supply the carbohydrates for the bacteria and the bacteria provide usable nitrogen
8 Recycling NitrogenThe bodies of dead organisms contain nitrogen (proteins & nucleic acids)Urine and dung also contain nitrogenDecomposers break down these materials and release the nitrogen as ammonia (NH3), which becomes ammonium (NH4 +) in the soilProcesses known as ammonification, and makes nitrogen available to other organisms again.
9 Recycling NitrogenSoil bacteria take up NH4 + and oxidize it into nitrites (NO2 -) and nitrates (NO3 -) through the nitrification processPlants use nitrates to form amino acids
10 DenitrificationWhen anaerobic bacteria break down nitrates and release nitrogen gas into the atmosphereHow nitrogen gas returns to the atmosphereAnimals must obtain nitrogen by eating plants and other organisms
11 Phosphorus cycle Land Plants animals Animal tissue and feces Urine Soluble soilphosphateDecomposers(bacteria andfungi)Loss indrainageRocks andmineralsPhosphatesin solutionDecomposers(bacteria & fungi)Animal tissueand fecesAquaticanimalsPlants andalgaePrecipitatesLoss to deep sediment
12 Phosphorous CycleThe movement of phosphorous from the environment to the organisms and back againPhosphorous is essential to animals for bones, teeth, and DNA/RNAPlants get it from the soil; Animals get it from other organismsExtremely slow cycle and doesn’t normally occur in atmosphere
13 Phosphorous CycleWhen rocks erode, small amounts of phosphorous dissolve as phosphate (PO3 -)Plants absorb phosphates through their rootsAlso added when wastes and organisms decomposeSome comes from fertilizer
14 Carbon cycle CO2 in atmosphere Diffusion Respiration Photosynthesis Plants and algaePlantsAnimalsIndustry and homeCombustion of fuelsCarbonates in sedimentBicarbonatesDeposition ofdead materialDepositionof deadmaterialFossil fuels(oil, gas, coal)Dissolved CO2
15 Carbon CyclePhotosynthesis and cellular respiration form the basis of this cycleIn photosynthesis, plants and other autotrophs use CO2, water, and solar energy to make carbohydratesAutotrophs and heterotrophs break down carbohydrates during cellular respiration
16 Carbon CycleThe byproducts of cellular respiration are carbon dioxide and waterDecomposers also release CO2 into the atmosphere when they break down organic molecules
17 Human Influences on the Carbon Cycle The concentration of atmospheric carbon has risen more than 30% in the last 150 yearsHumans contribute by burning fossil fuels and organic matter to produce energy
18 Fossil FuelsThe remains of organisms that have been transformed by decay, heat, and pressure into energy rich moleculesBurning releases the energy and CO2When large areas of land are burned, more CO2 is produced, and less plants are there to absorb it
19 The Greenhouse Effect and Carbon Dioxide The mean global temperature has increased about 1 °C since 1900, possibly because of trace gases like methane and CFC’s.The atmospheric level of methane has more than doubled since What could have caused this?Methane is the product of the bacterial decomposition of organic matter in the absence of oxygen. Mainly occurs in rice paddies and digestive tracts of termites (now in greater number because of the forests being destroyed).
21 Breaking the water cycle Deforestation breaks the water cyclegroundwater is not transpired to the atmosphere, so precipitation is not createdforest desertdesertification
22 Effects of deforestation 40% increase in runoffloss of water60x loss in nitrogen10x loss in calciumloss into surface water80nitrate levels in runoff40loss out of ecosystem!of nitrate (mg/l )Concentration4Deforestation21965196619671968Year
23 T or F: The process that returns nitrogen to the atmosphere is called ammonification. FALSE!Denitrification!!
24 How could humans affect the nitrogen cycle at the bacterial level? The addition of toxic chemicals to the soils; construction and deforestation can cause soil erosion
25 Pick 2 and write me an essay about each. 1 Pick 2 and write me an essay about each. 1. The role of bacteria in the carbon, nitrogen, and phosphorous cycles. 2. Explain the statement that nutrients cycle , but energy flows. 3. How do plants influence the various biogeochemical cycles? 4. How do humans influence the various biogeochemical cycles?
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