Transcript cycles ppt
Biogeochemical Cycles Unit Objective Students will be able to… Draw and label the water, carbon, and nitrogen cycles and explain what happens in each part of the cycle. Matter and Living Things An Introduction to Environmental Chemistry Brainstorm: What do living things require? atmosphere temperature energy TWANE water nutrients A Terrarium A terrarium represents the components of an ecosystem and illustrates the fundamentals of energy flow. Energy flow Heat energy Light energy Bacteria, protists, and fungi Chemical energy Chemical elements Ecosystems are supplied with a continual influx of energy from the sun and Earth’s interior. Is that enough? Nope! So life on earth depends on the cycling of chemicals through the ecosystem. The Major Earth Systems Geosphere – land, rocks, earth (Note: The surface land is called the lithosphere) Hydrosphere – water (oceans, lakes, rivers…) Atmosphere - air (78% N2, 21% O2) Biosphere – all living and decomposing organisms Cycling between them Biogeochemical Cycles Biogeochemical cycles is the flow of elements and compounds between biotic (living) components and abiotic (nonliving) components. * reservoirs (or sinks) compartments that store matter Water Cycle http://www.brainpop.com/science/earthsystem/watercycle/ Terms • Evaporation – liquid to a gas from the surface of a liquid • Condensation – gas collecting into clouds of water vapor • Precipitation – rain, sleet, or snow • Transpiration – evaporation of water from leaves • ground water – water that has seeped underground • Aquifer– water trapped and stored underground • Run off – water that follows the slope of land down to rivers, lakes and oceans Interesting Facts about Water • There is a constant amount of water on and in the earth. • Only 3% of the water is “fresh” • 70% of fresh water is frozen in glaciers. We have energy and water – now what nutrients do we need? Only about 24 elements! Six of them are macronutrients. We need them in large quantities! The rest are micronutrients. Ex: Calcium, Magnesium What are the BIG SIX??? CHNOPS Elements that make up Life!! CARBON The Carbon Cycle So what is carbon in the real world? • Main ingredient in all organic molecules • Used by plants in photosynthesis • Used to compose carbon dioxide and all macromolecules Can you name all • Graphite or diamond! three? Think back to Sports and Human Performance! How do you think the levels of carbon stay in check in the environment? The return of CO2 to the atmosphere by respiration closely balances its removal by photosynthesis. Photosynthesis Respiration Respiration The Carbon Cycle Play the Carbon Cycle Game http://www.windows2universe.org/earth/climate/carbon_cycle.html The Carbon Cycle Continual movement of carbon atoms through organisms, oceans, atmosphere & crust Atmosphere as CO2 Biosphere as proteins, sugars, Hydrosphere as CO2 Geosphere As limestone fossils & fossil fuel Where do we find the MOST carbon dioxide? 90% of Carbon Dioxide is stored in the ocean reservoir! What disrupts this balance? The burning of fossil fuels! Combustion Reaction: CH4 + O2 CO2 + H2O Global Warming is a result of the excess CO2 in the atmosphere http://www.brainpop.com/science/earthsystem/carboncycle/ Nitrogen – The Nitrogen Cycle http://www.brainpop.com/science/earthsystem /nitrogencycle/ Air (N2) Nitrifying Bacteria Plants Animals Decomposers Denitrifying Bacteria Air (N2) Key Concepts • Nitrogen in the soil (think fertilizer and manure) help plants grow. • Plants get Nitrogen from the soil and excess nitrogen results in excess growth (to a point) • Crop rotation keeps the nitrogen levels in the soil at healthy. • Nitrogen is needed to make proteins – we get it by eating plants or eating animals that eat plants. Bacteria are the Stars! • Bacteria take the nitrogen out of the air and put it in the soil • Other bacteria take the nitrogen out of the soil and puts it in the air • Without bacteria there would be no nitrogen cycle. What happens when humans disrupt the Nitrogen Cycle? Infertile land from using all the nitrogen up (this is why we have crop rotation) Algae blooms from fertilizer runoff into lakes and streams – These use up all the oxygen Acid Rain from polluting gases Check for Understanding: Think, Pair, Share What would happen if all the decomposers went on “strike” and stopped working? Which cycles would it affect and how? Connection to Space? These biogeochemical cycles is part of what makes a planet habitable