美国环境保护概论（二）

1、from your text, Principles of EnvironmentalScience: Inquiry and Applications, 3rd ed. William and Mary Ann Cunningham. (New York: McGraw-Hill, 2006)Chapter Two: Principles of Ecology: Matter, Energy and Life1Chapter Two Key Terms McGraw-Hill Course Glossary Acids Atom Bases Biological community Biom

2、ass Carbon cycle Carnivores Cellular respiration Chemical compounds Conservation of matter Consumers Decomposers Ecology Ecosystem Energy First law of thermodynamics Food web Herbivores Ions Kinetic energy Matter Metabolism Molecules Nitrogen cycle Omnivores Organic compounds pH Photosynthesis Popul

3、ation Potential energy Primary producers Productivity Second law of thermodynamics Species Tropic level2Chapter Two - TopicsPrinciples of Matter & EnergyThe Building Blocks of Earth and LifeSunlight: Energy for LifeEnergy and Matter and the EnvironmentBiochemical Cycles and Life Processes3Part 1: Pr

4、inciples of Matter and EnergyTo understand how ecosystems function, it is important to first know something about how energy and matter behave - in the universe and in living things. It is also important to understand the basic building blocks of life, starting with cells and organisms, and proceedi

5、ng to communities and populations.4EcologyThe scientific study of relationships between organisms and their environmentExamines the life histories, distribution, and behavior of individual species, as well as the structure and function of natural systems at the level of populations, communities, eco

6、systems, and landscapesEncourages us to think holistically about interconnections that make whole systems more than just the sum of their individual partsExamines how and why materials cycle between the living and nonliving parts of our environment5Matter and EnergyMatter and energy are essential co

7、nstituents of both the universe and living organisms.Matter - everything that takes up space and has massEnergy - the capacity to do work6Potential vs. Kinetic EnergyPotential energy - stored energy that is latent but available for useKinetic energy - the energy contained in moving objectFigure 2.1

8、text7Energy QualityLow Quality Energy Diffused, dispersed, or low in temperature Difficult to gather and use for productive purposes Example: heat stored in the oceans High Quality Energy Intense, concentrated, or high in temperature Useful in carrying out work Example: high-voltage electrical energ

9、yMany of our most common energy sources are low-quality and must be concentrated or transformed into high-quality sources before they are useful to us.8Conservation of MatterUnder ordinary circumstances, matter is neither created nor destroyed. It is recycled endlessly. Matter is transformed and com

10、bined in different ways, but it doesnt disappear. Everything goes somewhere.The atoms and molecules in your body have passed through many other organisms, over millions of years.9Properties of EnergyEnergy cannot be recycled. Energy is reused, but it is constantly degraded or lost from the system.Mo

11、st energy used in ecosystems originates as solar energy. Green plants convert some of this energy to chemical energy, which is then converted to heat or kinetic energy by the animal that eats the plant. 10First Law of Thermodynamics Energy cannot be created or destroyed, only changed Second Law of T

12、hermodynamicsWith each successive energy transfer or transformation in a system, less energy is available to do work. Even though the the total amount of energy remains the same, the energys intensity and usefulness deteriorate.The second law recognizes the principle of entropy, the tendency of all

13、natural systems to move towards a state of increasing disorder.Laws of Thermodynamics11The Building Blocks of Earth and LifeThe basic units of matter are called “elements”, which cant be subdivided chemically into smaller units. Elements make up molecules and compounds. It is important to understand

14、 basic chemistry in order to understand the critical role of chemistry in Environmental Science. 12Atoms, Molecules, and CompoundsMost material substances can exist in three interchangeable states: solid, liquid, or gas. Element - substance that cannot be broken down into simpler substances by ordin

15、ary chemical reactionsAtom - the smallest particle that exhibits the characteristics of an elementMolecule - a combination of two or more atomsCompound - a molecule made up of two or more kinds of atoms held together by chemical bonds13Fig. 2.314Periodic Table of the Elements15Just four elements - c

16、arbon, hydrogen, oxygen, and nitrogen - make up over 96% of the mass of most organisms.Elements and Environmental Science16Chemical BondingIonic Bond - Formed when one atom gives up an electron to another atom.Covalent Bond - Formed when two or more atoms share electrons.Energy is needed to break ch

17、emical bonds.Energy is released when bonds are formed.17Fig. 2.418Acids and BasesAcids are compounds that readily release hydrogen ions (H+) in water.Bases are substances that readily take up hydrogen ions (H+) and release hydroxide ions (OH-) in solution.Strength measured by concentration of H+.pH

18、scale0-1419Fig. 2.520Water Molecule21Water: A Unique CompoundSixty to 70 percent of the weight of living organismsMedium in which all of lifes chemical reactions occurGood electrical conductorHighest surface tension of any common, natural liquidLiquid over a wide temperature rangeExpands when it cry

19、stallizes, unlike most substancesHigh heat of vaporizationHigh specific heat22 23Cells: The Fundamental Units of LifeMicroscopic organisms, such as bacteria and protozoa, are composed of single cells.The human body contains several trillion cells of about two hundred distinct types.Enzymes catalysts that speed up the rate of chemical reactions in living systemsMetabolism - all the energy and matter exchanges that occur within a living cell or organism24The wavelengths of visiblelight drive photosynthesis.The Electromagnetic Spectrum25Photosynthe