4.3 Carbon Cycling Flashcards
Describe process of oxidation of methane
Methane is oxidized to carbon dioxide and water in the atmosphere
Describe process of methanogenesis
Methane is produced from organic matter in anaerobic conditions by methanogenic archaeans and some diffuses into the atmosphere
Describe process of absorption of carbon dioxide
Carbon dioxide diffuses from the atmosphere or water into autotrophs
Describe process of cellular respiration (opposite of photosynthesis)
Carbon dioxide is produced by respiration and diffuses out of organisms into water or the atmosphere
Describe process of carbon dioxide in solution.
In aquatic habitats carbon dioxide is present as a dissolved gas and hydrogen carbonate ions. (Carbon dioxide is soluble in water)
Describe the process of carbon fixation (photosynthesis)
Autotrophs (plants) carbon dioxide from atmosphere and convert it into carbohydrates (sugars), lipids and all the other carbon compounds.
What is fossilized organic matter?
Partially decomposed organic matter from past geological eras was converted into oil and gad in porous rocks or coal.
What forms of fossilized carbon are there?
Peat, Coal, Oil and Natural gas, Limestone
How is peat formed?
Peat forms when organic matter is not fully decomposed because of anaerobic conditions in waterlogged soils. Saprotrophs cannot thrive in these conditions, leaving dead organic matter not fully decomposed.
How is coal formed
Partially decomposed organic matter from past geological eras was converted into coal. Coal is formed when deposits of peat are buried under other sediments. The peat is compressed and heated gradually turning into coal.
How is oil and natural gas formed?
Partially decomposed organic matter from past geological eras was converted into oil and gas in porous rocks. This is formed in the mud at the bottom of seas and lakes. Conditions are usually anaerobic and so decomposition is often incomplete. As more mud or other sediments are deposited the partially decomposed matter is compressed and heated. Chemical changes occur which produce liquid carbon compounds or gases (also known as crude oil and natural gas)
How is Limestone formed?
Animals such as reef-building corals and molluscs have hard parts that are composed of calcium carbonate and can become fossilized in limestone. In tropical seas calcium carbonate is also deposited by precipitation in the water. This results in limestone rock where the deposited hard parts are often visible as fossils
What is a combustion reaction?
Carbon dioxide is produced by the combustion of biomass and fossilized organic matter. When organis matter is heated to its ignition tempertature in the presence of oxygen it will set light and burn.
Construct a diagram of the carbon cycle
plants/producers fix carbon (dioxide)/use carbon (dioxide) in photosynthesis; sugars/carbon compounds (produced) in plants/producers from photosynthesis; (carbon compounds in) plants/producers eaten by animals/primary consumers/herbivores; (carbon compounds in) primary consumers eaten by secondary consumers/ passed along food chain; carbon compounds/sugars/organic molecules digested and absorbed by consumers; carbon dioxide released by cell respiration (in plants/animals/ consumers); plants/animals die and are decomposed by (saprotrophic) bacteria/fungi; carbon dioxide released by cell respiration in bacteria/fungi/ decomposers; enzymes released to digest/hydrolyse carbon compounds in organic matter; forest fires/combustion releases carbon dioxide; humans burn fossil fuels adding carbon dioxide to the atmosphere;
What is the precautionary principle?
• Some human-induced change can be very large (perhaps catastrophic) • Those responsible for the change must prove it will cause no harm before proceeding • Appropriate (environmental/medical etc.) example e.g. companies must immediately reduce emissions of greenhouse gases even though proof of human impact on global warming is still debated • Is reverse of historical practice
