Cycling of Matter Flashcards
What is environmental sustainability dependent on?
Environmental sustainability depends on the dynamic equilibrium of ecosystems, where the cycling of matter and flow of energy between Earth’s spheres maintain balance.
What are biogeochemical cycles?
The movement of matter on Earth through closed loops, including cycles like water, nitrogen, and carbon.
What are the steps in the water cycle?
Evaporation: Liquid to gas (more in summer).
Condensation: Gas to liquid (cloud formation).
Precipitation: Water returns to the surface (rain, snow).
Transpiration: Water evaporates from plant leaves.
Run-off: Water moves from land into lakes and oceans.
What are human impacts on the water cycle?
Activities like deforestation, urbanization, and pollution alter the natural flow of water.
What is the role of carbon in life?
Carbon is the basic building block of life and exists in the atmosphere, oceans, organisms, rocks, and fossil fuels.
What are carbon sinks?
Carbon sinks hold CO₂, including the bodies of plants and animals and dissolved CO₂ in oceans.
What is the difference between photosynthesis and cellular respiration?
Photosynthesis (in plants):
Light energy + CO₂ + H₂O → Glucose + O₂
Cellular Respiration (in all living things):
Glucose + O₂ → CO₂ + H₂O + Energy
How do human activities impact the carbon cycle?
Burning fossil fuels releases stored CO₂ into the atmosphere.
Deforestation reduces photosynthesis, leaving more CO₂ in the air.
What are the key roles of nitrogen?
Essential for DNA and other molecules in the body.
78% of the atmosphere is nitrogen, but humans can’t use atmospheric nitrogen directly.
What are the processes in the nitrogen cycle?
Nitrogen Fixation: Bacteria convert N₂ into usable nitrates.
Assimilation: Plants use nitrates.
Denitrification: Bacteria convert nitrate back into nitrogen gas.
What is eutrophication, and how does it occur?
Fertilizer runoff increases nitrogen in lakes, causing algae overgrowth.
Algae block sunlight, killing underwater plants.
Decomposition reduces oxygen, creating dead zones.
What is the impact of human use of fertilizers on the nitrogen and carbon cycles?
Fertilizers add nutrients to soil but also lead to eutrophication and affect natural nutrient cycling.
