My AP Biology Thoughts  Unit 1 Episode #36Segment 1: Introduction To The Carbon Cycle

Carbon cycle Def 

• The way nature reuses carbon atoms
• The process in which carbon travels from the atmosphere into organisms and the Earth and back into the atmosphere

Background info about cycle

Carbon in constant state of movement from place to place and stored in reservoirs - moves between these reservoirs through photosynthesis, burning fossil fuels, respiration, etc.

• Cycle = cyclic - if you start at one reservoir, you will get back to that same reservoir
• Earth = closed system - amount of carbon on the planet never changes
• Nature keeps carbon levels balanced - amount of carbon released from reservoirs equal to amount obtained by same reservoirs

Steps

• Carbon moves from atmosphere to plants - carbon first came from frequent volcanic activity and asteroid impacts - carbon attached to oxygen in CO2
• For photosynthesis, CO2 is pulled from the air by plants to help in the process of producing food in the form of glucose which the plants consumes
• Carbon moves from plants to animals through food chains - animals eat these plants that have this carbon that the plants got from atmosphere
• Carbon moves plants and animals to soil - bodies, wood, leaves decay - carbon released as production from decomposition reaction go into ground - buried sometimes and turned in fossil fuels in millions of years
• Fossil fuels burned as human energy resources, carbon is then moved to the atmosphere as carbon dioxide - every year, 5.5 billion tons of carbon is released by burning fossil fuels and around 60% of this amount stays in the atmosphere while remainder becomes dissolved in seawater
• Carbon can get to atmosphere by respiration - release carbon dioxide as animals exhale - producers use energy from sunlight to make bonds between carbon atoms; animals break these bonds to release the energy they contain - turns carbon compounds into single carbon units - released into atmosphere as carbon dioxide
• Carbon could be released back into the atmosphere - volcanoes erupt, fires blaze, solid waste
• Carbon moves from the atmosphere to bodies of water - bodies of water absorb carbon from the atmosphere - dissolved into water
• Oceans release CO2 - carbon dioxide from atmosphere comes into contact with ocean water - reacts with water molecules to form carbonic acid
• When carbonic acid > carbon dioxide amount in the atmosphere, some carbonic acid may be released into the atmosphere as carbon dioxide

Segment 2: Getting Into Specifics: The Carbon Cycle

• Geosphere
• Geological component of the carbon cycle - operates slowly 
• Important determinant of amount of carbon in the atmosphere 
• Of the carbon stored in geosphere, 80% of it is limestone and its derivatives which...