The Carbon Cycle Notes PDF

THE CARBON CYCLE Unit 5: LT 1 METABOLISM  Recall from unit 1 that all living things require and use energy. This is referred to as Metabolism.  Metabolism is the complex of physical and chemical processes occurring within a living cell or organism that are necessary for the mainte...

THE CARBON CYCLE Unit 5: LT 1 METABOLISM  Recall from unit 1 that all living things require and use energy. This is referred to as Metabolism.  Metabolism is the complex of physical and chemical processes occurring within a living cell or organism that are necessary for the maintenance of life. In metabolism some substances are broken down to yield energy for vital processes while other substances, necessary for life, are synthesized requiring energy.  Recall the first law of thermodynamics:  Energy cannot be created or destroyed (it can only change forms).  Two important reactions are the basis of energy capture and conversion in the biosphere, photosynthesis and cell respiration! PHOTOSYNTHESIS  Plants and other photosynthetic organisms (some bacteria and protists) capture energy from sunlight and use it to make sugars-glucose (organic molecules), which they can then use in their cells.  Plants use sunlight, water, and CO 2 (carbon dioxide) to produce sugars (glucose) and O2 (oxygen gas)  PHOTOSYNTHESIS EQUATION Sunlight energy + 6H2O + 6CO2  C6H12O6 + 6O2 CELLULAR RESPIRATION (AEROBIC – USES O2)  Glucose is one product of photosynthesis  Organisms take in sugars (glucose) made by photosynthetic organisms and break it down to release energy (energy is released when bonds of glucose are broken); producers make their own sugars (glucose) during photosynthesis and break it down to release energy  Respiration uses sugars (glucose) and O 2 (oxygen gas) to produce water, CO2 (carbon dioxide), and cellular energy (called ATP)  CELL RESPIRATION EQUATION (AEROBIC) C6H12O6 + 6O2  6H2O + 6CO2 + ATP (energy) CARBON CYCLE  Photosynthesis and Respiration are basis for the biological carbon cycle (inverses of one another)  Photosynthesis takes in CO2 and H2O and releases O2 to the atmosphere and makes sugars (glucose= C6H12O6) in the plant  Respiration takes in O2 and sugars (glucose= C6H12O6) and releases CO2 and H2O to the atmosphere (All organisms use some form of respiration)  These both occur in terrestrial (land) and aquatic (water) ecosystems CARBON CYCLE  Decomposition by bacteria returns carbon compounds to the soil from dead organisms  Erosion and volcanic activity release CO2 to the atmosphere and oceans  Sedimentary rock contains large amounts of carbon compounds which can be released when rock is broken down  Human activity increases CO2 levels in the atmosphere  Burning of fossil fuels increases CO in the 2 atmosphere  Deforestation increases CO (since plants would 2 normally take in the CO2)  CO production by respiration and CO use by 2 2 photosynthesis would be balanced if not for human activity DIAGRAM