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Biogeochemical Cycles. Chapter 3 Lesson 4. Introduction. Every organism needs nutrients to build tissues and carry out life functions. Like water, nutrients pass through organisms and the environment. 3 nutrient pathways: move carbon, nitrogen, and phosphorus through the environment.
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Biogeochemical Cycles Chapter 3 Lesson 4
Introduction • Every organism needs nutrients to build tissues and carry out life functions. • Like water, nutrients pass through organisms and the environment. • 3 nutrient pathways: move carbon, nitrogen, and phosphorus through the environment. • Oxygen plays an important role in all 3 Nutrient Cycles.
Carbon Cycle Carbon is a major component of all organic compounds, including carbohydrates, lipids (fats), proteins, and DNA. • During Photosynthesis, plants use the carbon to build carbohydrates. • Organisms die, decomposers break down the bodies, releasing carbon to the environment. • Geologic forces can turn accumulated carbon into carbon-containing rocks or fossil fuels. • When animals break down “food”, carbon dioxide is released into the environment as a by-product.
The Carbon Cycle Photosynthesis and Cellular Respiration form the basis of the carbon cycle.
Photosynthesis • Performed only by plants and plant-like organisms (algae) • Process where CO2, H2O, and sunlight are converted into O2 and glucose (carbohydrate) • Chemical Formula: CO2 + H2O → O2 + C6H12O6 Photosynthesis takes place in the leaf .
Cellular Respiration • Opposite of photosynthesis • Defined as the breakdown of glucose by cells to create energy • Glucose & O2 are broken down into H2O, CO2, and energy • Done by ALL living things • Chemical Formula: C6H12O6 + O2→ CO2 + H2O
So…What’s the Problem? • If it were just photosynthesis and cellular respiration, the cycle would be balanced. • Humans have disrupted the carbon cycle through combustion- burning of fossil fuels. • Excess CO2 has caused global climate change which has caused the melting of polar ice caps, severe storms, and floods.