Water, nitrogen, carbon, and oxygen

 Bio.2.1 Analyze the interdependence of living organisms within their environments.  Bio Analyze the flow of energy and cycling of matter (such as water, carbon, nitrogen and oxygen) through ecosystems relating the significance of each to maintaining the health and sustainability of an ecosystem.

 Carbon – oxygen cycle  Nitrogen cycle  Nitrogen fixation  Denitrification  Water cycle  Evaporation  Transpiration  Condensation  Precipitation

 All organisms contain carbon and oxygen  Both elements exist in the atmosphere  Plants use photosynthesis to convert CO 2 from the atmosphere into carbohydrates (sugars) Carbon cycle

 Uses sunlight to produce chemical energy, which is stored between chemical bonds  The carbon and oxygen in carbohydrates passes between organisms through feeding relationships

 Carbon in carbohydrates and other compounds is returned to the atmosphere when decomposers break down wastes  Carbon is released when organisms break down carbohydrates (such as glucose) into CO 2 and H 2 O during respiration  This process also uses O 2 released during photosynthesis

 Continuous transfer of carbon and oxygen between living organisms  Involves important geological processes  Formation of fossil fuels  Burning of fossil fuels  Volcanic eruptions

 Coal, Oil, Natural Gas  Formed over millions of years  Ancient plants and microorganisms were gradually changed into fossil fuels through high heat and pressure  Carbon in their bodies was stored as fossil fuels Fossil Fuel formation

 When fossil fuels are burned carbon dioxide is released  Carbon is also released to the air when wood and charcoal are burned

 Store huge amounts of carbon (carbon reservoir)  Released by forest fires, natural or human induced  As fires burn, they consume oxygen, removing it from the atmosphere SAS QL# 952

 Continuous movement of nitrogen between organisms, water, rocks, minerals, and atmosphere  Essential part of amino acids, ATP, and nucleic acids Nitrogen Cycle - YouTube

 Atmosphere is about 78% nitrogen (N 2 )  Atmospheric nitrogen is changed in form through nitrogen fixation  Nitrogen Fixation is a process where certain soil bacteria break down nitrogen gas in the atmosphere and turn it into a form plants and animals can use Nitrogen fixation

 Some soil bacteria have a relationship with plants (legumes) in which the bacteria convert nitrogen gas in exchange for carbohydrates  Animals consume this nitrogen and pass it on to decomposers

 When organisms die, nitrogen in their cells returns to the environment  Under low oxygen conditions in the soil and marine environments, bacteria convert nitrogen compounds into nitrogen gas – denitrification  Denitrification returns nitrogen to the atmosphere

 AKA the hydrologic cycle  Continuous circulation of water among organisms, atmosphere, and surface  Driven by energy from the sun

 Evaporation – change of a liquid to a gas  Heat from the sun changes liquid water into vapor  Cellular respiration – breathing, breaking down carbohydrates into CO 2, H 2 O, and energy  Water is a waste product  Transpiration – the release of water vapor through the stomata (openings) of leaves  Plants use this process to cool themselves Transpiration - YouTube

 Condensation – process when gas changes to a liquid through loss of thermal energy (cooling)  Responsible for cloud formation  Precipitation – water falls from the atmosphere

 Oceans, lakes, glaciers, and plants  Freshwater is stored in groundwater, glaciers, and ice caps

 Water flows over earth’s surface and can run off land or flow underground to nearby bodies of water

 Organisms use water and the materials carried in water to carry out life processes  Wastes may exit by dissolving in water and may be removed in urine, sweating  Water re-enters the water cycle by evaporating from skin  Transpiration!