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Matter, Energy, and Life

Matter, Energy, and Life. Chapter 3. BASICS. Matter - Everything that has mass and takes up space. Solid - Liquid - Gas Elements - Substances that cannot be broken down into simpler forms by ordinary chemical reactions. Periodic Table. Basics.

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Matter, Energy, and Life

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  1. Matter, Energy, and Life Chapter 3 Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  2. BASICS • Matter - Everything that has mass and takes up space. • Solid - Liquid - Gas • Elements - Substances that cannot be broken down into simpler forms by ordinary chemical reactions. • Periodic Table Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  3. Basics • Atoms - Smallest particles exhibiting characteristics of the element. • Protons - Neutrons - Electrons • Atomic Number: # Protons • Isotope - Forms of an element differing in atomic mass. (Different # of neutrons) Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  4. Basics • Molecule: Two or more atoms joined together. • Compound: Two or more different types of atoms joined together. • Chemical Bond - Forces (chemical energy) holding atoms together in molecules. • Covalent - Sharing of electrons • Ionic - Cations and Anions • Hydrogen - Unequal attraction of shared electrons: Water Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  5. Molecules and Compounds Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  6. Ions, Acids, and Bases • Ions - Atoms that contain more or fewer electrons than protons. • Acids - Substances that release Hydrogen ions. • Bases - Substances that readily bond with Hydrogen ions. • pH Scale: 0-14 • < 7 Acidic • > 7 Basic Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

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  8. Organic Compounds • Organic Compounds - Material making up biomolecules. Formed by rings and chains of Carbon. • Four major categories: • Lipids • Carbohydrates • Proteins • Nucleic Acids Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  9. Cells • Cells - Minute compartments in a living organism which carry out process of life. • Surrounded by lipid membrane controlling flow of materials in and out of cell. • Interior sub-divided into organelles and sub-atomic particles. • Enzymes - Class of proteins - molecular catalysts regulating chemical reactions. • Metabolism - Multitude of enzymatic reactions performed by an organism. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  10. ENERGY • Energy - Ability to do work. • Kinetic - Energy in moving objects. • Potential - Stored energy. • Chemical - Stored in food or fossil fuels. • Power - Rate of doing work. • Heat - Total kinetic energy in a substance not associated with bulk motion. • Temperature - Measure of speed of motion of atoms in a molecule. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  11. Thermodynamics • Energy must be supplied from an external source to keep biological processes running. • Energy flows in a one-way path through living systems and into a temperature sink. • First Law of Thermodynamics - Energy is neither created nor destroyed. • Second Law of Thermodynamics - With each successive energy transfer, less energy is available to perform work. • Entropy Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  12. ENERGY FOR LIFE • Ultimately, most organisms depend on the sun for energy needed to carry out life processes. • Solar energy is essential for (2) reasons: • Warmth • Photosynthesis • Radiant energy transformed into useful, high-quality chemical energy in the bonds of organic molecules. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  13. Energy For Life • Of all solar radiation reaching the earth’s surface, about 10% is Ultraviolet, 45% is Visible, and 45% is Infrared. • Most of energy is absorbed by land or water, or reflected back into space. • Only about 1-2% of the sunlight falling on plants is captured for photosynthesis. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  14. Electromagnetic Spectrum Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  15. Photosynthesis • Occurs in membranous organelles of green plant cells called chloroplasts. • 6H20+6CO2 + solar energy = C6H12O6+6O2 • Water and carbon dioxide in the presence of sunlight yields glucose (sugar) and oxygen. • Glucose serves as primary fuel for all metabolic processes in plant cells. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  16. Respiration • Photosynthesis captures energy, while cellular respiration releases energy. • Cellular respiration splits carbon and hydrogen atoms from the sugar molecule and recombine them with oxygen to re-create carbon dioxide and water. • C6H12O6 + 6O2 = 6H2O +6CO2 + energy Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

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  18. SPECIES TO ECOSYSTEMS • Population - All members of a species living in a given area at the same time. • Community - All of the populations of organisms living and interacting in a particular area. • Ecosystem - Biological community and its physical environment. • Somewhat user-defined • Open or closed boundaries Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  19. Food Chains • Photosynthesis is described as Primary Productivity because it is the basis for almost all other growth in an ecosystem. • Manufacture of biomass by organisms eating plants is termed Secondary Productivity. • Food Chain - Linked feeding series. • Food Web - Most consumers have multiple food sources. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

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  21. Trophic Levels • Trophic Level - Expression of an organism’s feeding status in an ecosystem. • Producers (plants) • Consumers • Primary, Secondary, Tertiary • Most terrestrial food chains relatively short. • Aquatic food chains tend to be longer. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

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  23. Trophic Levels • Organisms can also be identified by the type of food they consume: • Herbivores (Plants) {Deer} • Carnivores (Meat) {Wolves} • Omnivores (Plants/Meat) {Bears} • Scavengers (Carcasses) {Crows} • Detritivores (Debris) {Ants} • Decomposers (All) {Bacteria} Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  24. Ecological Pyramids • Due to Second Law of Thermodynamics, food chains often form an inverted pyramid. • Metabolism • Predator efficiency < 100% • 10% Rule (Energy / Biomass) • 100 kg clover • 10 kg rabbits • 1 kg foxes Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  25. MATERIAL CYCLES • Carbon Cycle • Begins with intake of CO2 during photosynthesis. Carbon atoms are incorporated into glucose and then: • Remain in plant material until death. • Eaten by predator • Respiration • Excretion • Incorporation • Death (Decomposers) Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  26. Carbon Cycle Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  27. Nitrogen Cycle • Plants uptake inorganic nitrogen from the environment and build protein molecules which are later eaten by consumers. • Nitrogen-fixing bacteria change nitrogen to a less mobile, more useful form by combining it with hydrogen to make ammonia - used to build amino acids. • Members of bean family (legumes) have nitrogen-fixing bacteria living in their root tissue. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  28. Nitrogen Cycle • Nitrogen re-enters the environment: • Death of organisms • Excrement and urinary wastes • Nitrogen re-enters atmosphere when denitrifying bacteria break down nitrates into N2 and nitrous oxide (N2O)gases. • Humans have profoundly altered nitrogen cycle via use of synthetic fertilizers, nitrogen-fixing crops, and burning fossil fuels. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  29. Nitrogen Cycle Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  30. Phosphorous Cycle • Phosphorous compounds are leached from rocks and minerals and usually transported in aqueous form. • Taken in and incorporated by producers. • Passed on to consumers. • Returned to environment by decomposition. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  31. Phosphorous Cycle Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

  32. Sulfur Cycle • Most sulfur tied up in underground rocks and minerals. Inorganic sulfur released into air by weathering and volcanic eruptions. • Cycle is complicated by large number of oxidation states the element can assume. • Human activities release large amounts of sulfur, primarily by burning fossil fuels. • Important determinant in rainfall acidity. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

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