Sunday, June 19, 2011
4.9 describe the stages in the carbon cycle, including respiration, photosynthesis, decomposition & combustion
"The element carbon is present in all living organisms. It's recycled through various processes, which are described in the carbon cycle."
Most chemicals in organisms contain carbon. When they die, the carbon is recycled, so future organisms can can use it.
1. The movement of carbon between land, ocean, & atmosphere is through the processes of photosynthesis and respiration. Carbon enters the atmosphere as carbon dioxide from respiration &
C6H12O6 + 6O2 6CO2 + 6 H2O + energy
Glucose+oxygen= carbon dioxide + water+ energy
energy (sunlight) + 6CO2 + H2O C6H12O6 + 6O2
Carbon dioxide + water (+ sunlight) --> glucose + oxygen
2. Carbon dioxide is absorbed by producers to make carbohydrates (sugars) in photosynthesis.
3. Animals feed on the plant passing the carbon compounds along the food chain. Most of the carbon they consume is exhaled as carbon dioxide formed during respiration. The animals & plants eventually then die.
4. The dead organisms are eaten by decomposers & the carbon in their bodies is returned to the atmosphere as carbon dioxide.
5. Sometimes decomposition is blocked. The plant and animal material may then be available as fossil fuel in the future for combustion. Fossil fuels ( oils+coals) ----> CO2
Monday, June 13, 2011
Burning Fossil Fuels causes air pollution. They release gases such as carbon monoxide, carbon dioxide, sulfur dioxide & nitrogen oxides. We burn fossil fuels in cars, power stations & factories to produce energy. These gases cause problems such as acid rain & global warming.
Saturday, June 11, 2011
Understand how an increase in greenhouse gases results in an enhanced greenhouse effect & that this may lead to global warming & it's consequences.
The enhanced green house effect is whereby the greenhouse gases (carbon dioxide, methane, & CFC'S) are being released into the atmosphere at a far greater rate than would happen through natural processes and thus their concentrations are increasing ---> Climate Change/Global Warming (increase in average temps)
Consequences: Change in the worlds Biomes.
Example: Polar Regions (Arctic+Antarctica): melting of ice caps ---> raised sea levels --> change in winds + ocean currents. + Plants will die, & animal migrating patterns will change.