Oxygen Cycle
Biogeochemical Cycles • Defined: Movement of water through the Earth and its atmosphere • 75% of the Earth is covered in water • Less than 1% is drinkable. • Most water is salty or frozen Water Cycle Pathway ......
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• Evaporation: Heat changes water from a liquid to a gas • Transpiration: Water evaporates from the leaves of plants through openings called stomata Water Cycle Pathway ......
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• Water vapor starts to cool…condensation occurs • Condensation: process where water vapor turns into a liquid Water Cycle Pathway ......
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• Precipitation: Rain, snow, sleet, or hail falls when water drops become heavy • Runoff: Water runs down hill into rivers, lakes, streams, oceans… • Infiltration: Water soaks into the soil and collects as groundwater
Oxygen Cycle
O2
O2
• Autotrophs: Release O2 into atmosphere by photosynthesis
• Most life needs O2 for cellular respiration – Creates ATP (energy) for cells Carbon (C) Cycle CO CO CO CO2 2 CO2 CO2 2 2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2
CO2
CO2 glucose
glucose glucoseCO2 glucose glucoseglucose
Carbon • Plants
– Absorb CO2 for photosynthesis – Release glucose (C6H12O6) after photosynthesis Carbon (C) Cycle CO CO CO CO2 2 CO2 CO2 2 2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2
CO2
CO2 glucose
glucose glucoseCO2 glucose glucoseglucose
Carbon • Animals – Glucose passed up the food chain
– CO2 exhaled into atmosphere Carbon (C) Cycle CO CO CO CO2 2 CO2 CO2 2 2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2
CO2
CO2 glucose
glucose glucoseCO2 glucose glucoseglucose
Carbon • Decomposers – Obtain glucose by feeding on dead organisms – Carbon released in their waste Carbon (C) Cycle CO CO CO CO2 2 CO2 CO2 2 2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2
CO2
CO2 glucose
glucose glucoseCO2 glucose glucoseglucose
Carbon • Human Contribution
– Release excess CO2 into atmosphere when fossil fuels (coal, oil, natural gas) are burned for energy – Cycle is out of balance Phosphorus (P) Cycle • Phosphorus needed to make ATP, DNA, lipids • Problem: No phosphorus in atmosphere P • Step 1: P Phosphorus P released by weathering of P rocks • Step 2: Producers P absorb P through their roots Phosphorus (P) Cycle • Step 3: Consumers ingest P • Step 4: Decomposers obtain P when feed on P the dead. P • Step 5: P Decomposers release P P within waste back into soil or water P • Cycle repeats P Phosphorus (P) Cycle P
P P
P • Human P Contribution – Adding excess P from fertilizers – P washes into lakes, etc… – Excess P causes extreme plant & algae growth • Nitrogen needed Nitrogen (N) Cycle to build nucleic acids (DNA/RNA)
N2 • Problem: Nitrogen in N atmosphere (N2) is unusable • Step 1: Bacteria N N in soil convert N2 into usable N forms N Usable N • Step 2: Bacteria absorb usable N Usable N • Step 3: Bacteria Nitrogen release N waste fixation into air Nitrogen (N) Cycle • Step 4: Producers absorb N N 2 through their roots N • Step 5: Consumers
N N ingest N through the food chain N • Step 6: N Usable N Decomposers obtain N from
Usable N dead organisms… Nitrogen fixation return N to soil in their waste Nitrogen (N) Cycle
OO2ONO N2N N N NO 2 NO O2 NO NO NN2 O2 NO
OO2
• How does lightning help? – Energy breaks atmospheric nitrogen into Nitrogen oxide – Nitrogen oxide falls in rain to soil Review 1) Name and define the 6 stages of the water cycle. 2) How is oxygen released into the atmosphere? 3) In which cellular process is oxygen removed and used from the atmosphere? 4) What are the 4 major types of organic molecules? 5) In which cellular process is carbon dioxide released into the atmosphere? 6) How are humans disrupting the carbon cycle? 7) Which objects release phosphorus over time? 8) How are humans disrupting the phosphorus cycle? 9) Which organisms help convert gaseous nitrogen into a usable form of nitrogen in the nitrogen cycle? 10) How do plants obtain nitrogen? 11) Of the major molecules that we have studied this year, which ones contain nitrogen and/or phosphorous?