Richard T. Wright Environmental Sciencekadima/ENVIRONMENTAL SCIENCE/ch03_lecture... · 2007. 9. 18. · Ecosystems: How They Work • Matter, energy, and life • Energy flow in ecosystems
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• Glucose• Proteins• Starch• Fats• Nucleic acids• All of the above
The BIG SIX:Needed by all living things in large quantities
Organic Molecules
Matter and Energy
• Matter: anything that occupies space and has mass.– Cannot be created or destroyed.– Can be changed from one form into another.– Can be recycled.– Can be measured where gravity is present.
Matter and Energy
• Energy: anything that has the ability to move matter, has no mass and does not occupy space.– Cannot be created or destroyed.– Can be changed from one form to another.– Cannot be recycled.– Can be measured.
Forms of Energy
• Kinetic– Energy in its
active form• Potential
– Potential that systems have to release kinetic energy
Energy Conversions
Laws of Thermodynamics
First Law: (CHANGE) Energy is neither created nor destroyed but may be converted from one form to another. NO FREE LUNCHES!
Second Law: (LOSS) In any energy conversion, you will end up with less usable energy thanyou started with. YOU CAN’T BREAK EVEN!
So how do we survive?
Example of the Laws of Conservation of Matterand Thermodynamics
Global WarmingGlobal Warming
Acid RainAcid Rain SmogSmog
Burning Coal = CO2 + SO + H2O + Ash +(CxHxSxOx) Light + Noise + Heat
Where from?
Entropy: Energy Changes in Organisms• Systems will go
spontaneously in one direction only which is toward increasing entropy.
• Entropy measures the degree of disorder of a system
Entropy underlies the second law of thermodynamics / the most of usable energy.
Entropy
First Principle of Ecosystem Sustainability
• Ecosystems use sunlight as their source of energy.
– Ecosystems need a constant input of energy
– Why?
How Ecosystems Use Sunlight As Their Source of Energy