1. 1 Principles of Environmental Science Inquiry and Applications Third Edition Cunningham Chapter 2 Lecture Outlines* *See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. 2 Principles of Ecology: Matter, Energy, and Life Chapter 2

3. 3 Outline: Principles of Matter and Energy Building Blocks of Life Chemical Bonds Acids and Bases Water Photosynthesis Food Webs Ecological Pyramids Biogeochemical Cycles

4. 4 PRINCIPLES OF MATTER AND ENERGY Matter - Has mass and takes up space.  Three phases - Solid - Liquid - Gas Law of Conservation of Matter  Under normal conditions, matter cannot be created or destroyed. - There is no away.

5. 5 Energy Energy - The capacity to do work.  Kinetic Energy - Energy contained in moving objects.  Potential Energy - Stored, latent energy available for use. Heat - Energy that can be transferred between objects of different temperature.  Specific Heat - Amount of heat required to warm one gram one degree C.

6. 6 Thermodynamics First Law - Energy is conserved.  Under normal conditions, it is neither created nor destroyed, but can be transferred or transformed. Second Law - With each successive energy transfer or transformation, less energy is available to do work.  Entropy (disorder) increases.

7. 7 BUILDING BLOCKS OF LIFE Atom - Smallest particle that exhibits the characteristics of an element.  Protons - Positively charged.  Electrons - Negatively charged.  Neutrons - Neutral. Ions - Charged atoms.  Cations - Positive charge.  Anion - Negative charge.

8. 8 Carbon-12 Atom

9. 9 BUILDING BLOCKS OF LIFE CONT’D Isotope - Atoms of a single element that differ in atomic mass.  Radioactive isotopes spontaneously decay or shed subatomic particles. - Half Life  Neutrons  Alpha, Beta, Gamma particles  Positrons

10. 10 BUILDING BLOCKS OF LIFE CONT’D Molecule  Group of atoms that can exist as an individual unit and that has unique properties. Compound  A molecule containing different kinds of atoms.

11. 11 Common Molecules

12. 12 Chemical Bonding Ionic Bond - Formed when an atom loses or gains one or more electrons. Covalent Bond - Formed when two or more atoms share electrons.  Energy is needed to break chemical bonds.  Energy is released when bonds are formed.

13. 13 Chemical Reactions Reactions start with reactants and produce products.  Oxidation - A molecule or atom loses an electron.  Reduction - A molecule or atom gains an electron.

14. 14 Acids and Bases Acids 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 scale - 0-14

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16. 16 Organic Compounds and Cells Organic compounds are molecules, often large and complex, built of carbon atoms. Enzymes facilitate chemical reactions in cells.  Metabolism refers to the multitude of enzymatic reactions performed by an organism.

17. 17 Qualities of Water Weight of living organisms 60-70% water. Universal solvent  Dissolved salt solutions conduct electricity. Cohesive, producing capillary action. Exist as liquid over a wide temperature range. Expands when crystallizes. High heat of vaporization. High specific heat.

18. 18 SUNLIGHT Sun is a fiery ball of exploding hydrogen gas. Radiant energy classified by wavelengths.  Intense energy has short wavelengths.  Lower energy has longer wavelengths.

19. 19 SUNLIGHT CONT’D Solar energy that reaches the earth’s surface is in, or near, the visible light wavelengths.  Drive photosynthesis. More than half of the incoming sunlight may be reflected or absorbed by atmospheric clouds, dust, or gases.  Short wavelengths are filtered out by gases in the upper atmosphere.

20. 20 Photosynthesis and Respiration Photosynthesis 6H 2 O + 6CO 2 + sun  C 6 H 12 O 6 (sugar) + 6O 2 Cellular Respiration C 6 H 12 O 6 +6O 2  6H 2 O + 6CO 2 + energy

21. 21 Energy Exchange

22. 22 Energy and Matter in the Environment Species - All organisms genetically similar enough to breed and produce live, fertile offspring in nature. Population - All members of a species that live in the same area at the same time. Biological Community - All populations living and interacting in an area. Ecosystem - A biological community and its physical environment.  Open vs. Closed

23. 23 Food Webs and Trophic Levels Productivity refers to the amount of biomass produced in a given are during a given time.  Primary Producers - Photosynthesize.  Consumers - Eat other organisms. Food Webs are series of interconnected food chains in an ecosystem.  Trophic Level refers to an individual’s feeding position in an ecosystem.

24. 24 Ecological Food Chain

25. 25 Trophic Levels Organisms can also be identified by the kinds of food they consume:  Herbivores - Eat plants.  Carnivores - Eat animals.  Omnivores - Eat plants and animals.  Detritivores - Eat detritus.  Decomposers - Breakdown complex organic matter into simpler compounds.

26. 26 Trophic Levels

27. 27 Ecological Pyramids Most ecosystems have huge number of primary producers supporting a smaller number of herbivores, supporting a smaller number of secondary consumers.  Second law of thermodynamics. - Ecosystems not 100% efficient.  10% Rule

28. 28 Ecological Pyramids

29. 29 BIOGEOCHEMICAL CYCLES Hydrological Cycle  Most of earth’s water is stored in the oceans, but solar energy continually evaporates this water, and winds distribute water vapor around the globe.

30. 30 Hydrologic Cycle

31. 31 Carbon Cycle Carbon serves a dual purpose for organisms:  Structural component of organic molecules.  Chemical bonds provide metabolic energy.

32. 32 Carbon Cycle

33. 33 Nitrogen Cycle Nitrogen makes up about 78% of the air, but plants cannot use N 2, the stable diatomic molecule in air.  Plants acquire nitrogen through nitrogen cycle. - Nitrogen-fixing bacteria.

34. 34 Nitrogen Cycle

35. 35 Phosphorus Cycle Abundant phosphorus stimulates plant and algal productivity.  Major component of water pollution. - Reduced levels of dissolved oxygen.

36. 36 Phosphorus Cycle

37. 37 Sulfur Cycle Sulfur compounds are important determinants of the acidity of water.  Particulates may also act as critical regulators of global climate. Sulfur cycle is complicated by a large number of possible oxidation states.

38. 38 Sulfur Cycle

39. 39 Summary: Matter and Energy Building Blocks of Life Chemical Bonds Acids and Bases Water Photosynthesis Food Webs Ecological Pyramids Biogeochemical Cycles

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