4.3 Carbon Cycle.pdf

4.3 Carbon Cycle IB Biology HL 1-2 Carbon ● Carbon is the backbone of all of the organic macromolecules ○ Carbohydrates (sugars) ○ Lipids (fats) ○ Amino acids (proteins) ○ Nucleic acids (genetic material) Where is Carbon Found? Carbon can be found throughout different environments on earth ● ●...

4.3 Carbon Cycle IB Biology HL 1-2 Carbon ● Carbon is the backbone of all of the organic macromolecules ○ Carbohydrates (sugars) ○ Lipids (fats) ○ Amino acids (proteins) ○ Nucleic acids (genetic material) Where is Carbon Found? Carbon can be found throughout different environments on earth ● ● ● ● Hydrosphere: water Biosphere: all places where life is found Geosphere: all places where rocks are found Atmosphere: air The Role of Autotrophs in the Carbon Cycle What do we mean when we say carbon cycles? ● ● What are some examples of autotrophs? ○ ○ What role do autotrophs play in the carbon cycle? ○ Autotrophs absorb inorganic carbon dioxide from the atmosphere and convert it into organic carbon based compounds to be eaten by consumers (photosynthesis) Carbon in Aquatic Ecosystems What happens when carbon dioxide from the air diffuses (dissolves) into water? ● Carbon dioxide is soluble in water ● Carbon dioxide is absorbed by aquatic autotrophs to produce carbon compounds (usually via photosynthesis) It also forms carbonic acid and lowers the pH of the aquatic environment ● Can you think of a consequence of rising atmospheric carbon dioxide levels? Cycling of Carbon Dioxide Why do producers need carbon dioxide? ● ● Terrestrial producers obtain carbon dioxide by absorbing it from the air Aquatic producers obtain carbon dioxide by absorbing it from the water Draw a Diagram of the Carbon Cycle Drawing a diagram of the carbon cycle ● ● What processes absorb carbon dioxide from the atmosphere? What processes release carbon dioxide into the atmosphere? Methane in the Carbon Cycle Carbon dioxide is the most common type of carbon compound released into the atmosphere, but it isn’t the only one. ● ● Methane, CH4, also finds its way into the atmosphere pretty frequently Methane is produced by specialized microbes that are common in ○ Wetlands (swamps/mires) ○ Mud shores of lakes ○ Digestive tracts of mammals and termites ○ landfill The Oxidation of Methane ● ● ● ● Combustion during cellular respiration: ○ C6H12O6 + 6O2→ 6CO2+ 6H2O Methane is the main component in natural gas When natural gas is burned, the following reaction takes place: ○ CH4 + 2O2 → CO2 + 2H2O So when methane is burned, large amounts of carbon dioxide are released into the atmosphere Peat as a Fossil Fuel Peat: a type of waterlogged soil that contains large amounts of partially decomposed organic matter How Does Peat Form? Formation of Peat 1. Dead organisms are covered in water 2. The weight of the water forces the air out, creating an anaerobic environment 3. Microorganisms that would normally decompose the dead material die off 4. Energy rich compounds are compressed and preserved Over time - heat and pressure cause the organic matter to transform into energy dense hydrocarbons (coal/oil) Peat as a Fossil Fuel ● Peat is used as a fossil fuel through burning ● Burning peat yields a lot of energy, but… ● To harvest peat you have to disrupt sensitive wetland environments ● Burning peat releases carbon dioxide into the environment Oil and Gas as Fossil Fuels (Nonrenewable) ● ● Oil, coal, natural gas, and other fossil fuels are energy rich and provide lots of usable energy, but… ○ Mining them is disruptive to sensitive habitats ○ Burning them releases carbon dioxide and other contaminants into the air Not renewable: they take millions of years to form and we burn them at a much faster rate than they are forming. Carbon Dioxide is Produced When Fossil Fuels are Used ● ● ● When biomass (wood, trash, leaves, etc.) is burned, carbon dioxide gets released into the atmosphere ○ fossil fuels vs. biofuels - carbon dioxide production is still a problem Biofuels - vegetables oils as fuel instead of traditional oil, coal, gas. Advantages: 1. You don’t have to disrupt sensitive habitats to mine them 2. The carbon dioxide they are releasing was just absorbed days ago by the plant (not millions of years ago like fossil fuels), making the cycle of time shorter Limestone ● ● Limestone is another very common carbon compound on earth. Limestone is inorganic, the majority is made of calcium carbonate (CaCO3) ○ Calcium carbonate is the main component of shells of marine organisms Production of limestone 1. Marine organisms absorb CO2 from their environments 2. Carbon dioxide is transformed into Calcium carbonate, which is used to make their shells 3. The animals die 4. Their shells accumulate on the ocean floor 5. Non-porous sedimentary rock layers form on top of the shells 6. Heat and pressure turn the shells into limestone over millions of years Limestone ● ● ● The formation of limestone is an important step in biosequestration Biosequestration: the process of removing carbon dioxide from the environment and locking it up in a substance for an extended period of time ○ Lot’s of research going on with this to combat climate change! When limestone is mined and then crushed up for concrete, it can release carbon dioxide back into the air, which disrupts the biosequestration of the atmospheric carbon. Atmospheric Carbon Dioxide Mauna Loa Observatory: ● Big Island, Hawaii ● Volcanic mountain ● NOAA research location These graphs are really important!!! Make sure you fully understand them!!! Carbon Cycle Diagram ● Draw a diagram to represent the carbon cycle that includes the following: ○ Combustion of fossil fuels ○ Carbon in dead organic matter ○ Egestion (release of organic material through waste) ○ Feeding ○ Photosynthesis ○ Storage of carbon in fossil fuels ○ Co2 in atmosphere ○ Cellular respiration in producer, consumers, saprotrophs, and detritivores ○ Feeding of organic material Methane Production & Oxidation (Methanogenesis) ● Methane is produced from organic matter in anaerobic conditions (as waste product ○ ○ ● A type of greenhouse gas Anaerobic - no oxygen present How does methanogenesis work? 1. Bacteria can convert organic matter into a mixture of organic acids, alcohol, hydrogen, and carbon dioxide 2. Bacteria use the organic acids and alcohol to produce acetate, carbon dioxide, and hydrogen 3. Archaeans use CO2, hydrogen, and acetate to produce methane Peat forms when organic matter is not fully decomposed! Combustion ● Combustion ○ ○ ○ ○ ○ Oxidation of organic matter once reaching ignition temperature in the presence of oxygen Releases CO2 into the atmosphere Ex. burning of coal, oil, and natural gases Combustion release CO2 stored in fossilized organic matter back into the atmosphere Cause of unbalanced environment! Limestone ● ● Molluscs & hard corals use calcium carbonate to create their solid structures/skeletons ○ Soft body decomposes upon death ○ Solid structures (calcium carbonate) will dissolve under acidic conditions ○ Limestone results from precipitation in neutral or alkaline condition Changes in pH in aquatic condition can negatively affect survival of aquatic organisms Carbon Cycle Diagram ● Draw a diagram to represent the carbon cycle that includes the following: ○ Combustion of fossil fuels ○ Carbon in dead organic matter ○ Egestion (release of organic material through waste) ○ Feeding ○ Photosynthesis ○ Storage of carbon in fossil fuels ○ Co2 in atmosphere ○ Cellular respiration in producer, consumers, saprotrophs, and detritivores ○ Feeding of organic material