Slide 1Matter Is Made Of Atoms, Molecules, And CompoundsChemical FormulasElectrical Charge Is An Important Chemical CharacteristicChemical Bonds Hold Molecules TogetherChemical Bonds Hold Molecules TogetherElements Of LifeElements and LifeThe ElementsThe Elements and LifeOrganic Compounds Have A Carbon BackboneCells Are The Fundamental Units Of LifeEnergyThermodynamics Regulates Energy TransfersFrom Species To EcosystemsWaterworldSometimes It Looks More Like ThisReasons to be a ”Water chauvinist".Material Cycles And Life ProcessesMaterial Cycles on the EarthReasons to be a "Carbon chauvinist".Carbon in the EarthCarbon in the BiosphereCarbon CyclesThe Carbonate-Silicate CycleThe Paradox of NitrogenSulfur in the EarthFrom Earth to EnvironmentAcid RainAcid RainPhosphorus in the EarthPhosphorus on LandPhosphorus in WaterDistinctive Aspects of the P CycleChapter 3 Matter, Energy, And LifeMatter Is Made Of Atoms, Molecules, And Compounds •Atom: simplest building block of chemicals•Element: a material composed of identical atoms•Compound: a combination of atoms in a fixed arrangement and proportion•Molecule: The simplest chemical unit of a compound (O2, H2O, CH4, C6H12O6 etc.)–Many materials (NaCl) don’t have moleculesChemical Formulas•Most Elements have symbols that are common sense: H (Hydrogen), Si (Silicon), etc.•Some, known in ancient times, have symbols from Latin: Fe (Ferrum = Iron), Au (Aurum = Gold), Na (Natrium = lye, for Sodium)•C6H12O6 = Glucose = 6 Carbon, 12 Hydrogen, 6 Oxygen•SiO2 = Quartz = 2 Oxygen for each SiliconElectrical Charge Is An Important Chemical Characteristic •Atoms contain three kinds of particles:–Protons (+) in the nucleus. Number of protons determines what an element is–Neutrons (0) in the nucleus. Bind the nucleus together–Electrons (-) orbiting the nucleus•Group together into shells•This is what interacts with other atoms•Atoms can gain or lose electrons and become electrically charged (Ions)Chemical Bonds Hold Molecules Together •Ionic: Ions of opposite charge attract each other. Example: NaCl, most minerals•Covalent: Atoms share electrons with neighbors. Example: Most carbon chemicals•Metallic: Electrons wander freely between atoms. Positive atoms held together by negative electron “glue”•Hydrogen: H and O in water molecules attracted to neighborsChemical Bonds Hold Molecules Together •Ionic bonding holds most rocks and minerals together•Covalent bonding holds living things together•Metallic bonding holds industrial civilization together•Hydrogen bonding gives water its solvent and heat-storing capacityElements Of Life •C, H, O, N, P, S are principal elements of life•Some elements like C can share more than one electron with a neighbor (multiple bonding)•Some elements like Fe and S can gain or lose electrons in more than one way•These versatile atoms can be used for–Energy storage–Information storage–Triggering chemical reactionsElements and Life•Some very abundant elements have no biological uses (Al, Si, Ti)•Some elements are essential in low amounts but toxic at greater levels (Cu, Se)–Everything is toxic at excessive levels•Some elements are toxic and have no biological functions (Lead, Mercury)The ElementsThe Elements and LifeOrganic Compounds Have A Carbon Backbone •Organic compounds contain carbon as their basic structural core–Chains (Petroleum)–Rings (Benzene, Toluene)•Simple carbon-bearing chemicals aren’t considered Organic–CH4: Methane–CO2: Carbon Dioxide–CaCO3: Calcite, the Main Constituent of LimestoneCells Are The Fundamental Units Of Life •Cell Membrane: Contains contents and processes, excludes foreign objects (mostly)•Nucleus: Where DNA resides–Simplest organisms lack nucleus•Mitochondria–Not to be confused with Midichlorians (MTFBWY)–Produce Energy for Cell–Have their own DNA–Probably originated as independent organismsEnergy•Energy Occurs In Different Types And Qualities •Thermodynamics Regulates Energy Transfers •Energy For Life –Extremophiles Live In Severe Conditions –Green Plants Get Energy From The Sun –Photosynthesis Captures Energy While Respiration Releases That EnergyThermodynamics Regulates Energy Transfers •First Law: Energy is Not Created or Destroyed–Can Change Form–Matter and Energy can be converted•Second Law: Entropy increases–Entropy is often likened to disorder but is not entirely the same–Entropy can decrease at expense of surroundingsFrom Species To Ecosystems •Organisms Occur In Populations, Communities, And Ecosystems •Food Chains, Food Webs, And Trophic Levels Link Species •Ecological Pyramids Describe Trophic LevelsWaterworldSometimes It Looks More Like ThisReasons to be a ”Water chauvinist".•Stays liquid over a wide range of temperatures. •Polar or asymmetrical molecule. Attracts ions easily - Good transporter of nutrients•Does not dissolve organic molecules (so we do not dissolve in our own cell fluids)Material Cycles And Life Processes•Sources: supply elements for life and physical processes–Example: Burning vegetation releases CO2•Sinks: remove materials from environment–Example: Plants remove CO2 from the air–Limestone removes CO2 from the air•Residence Time: How long an average atom or molecule remains in a system–Example: Water molecule in air, 10 daysMaterial Cycles on the Earth•The Hydrologic Cycle Moves Water Around The Earth –Oceans – Atmosphere – Land - Ocean•Nutrient Cycles–Ultimate Source: Rocks–Released by Weathering–Taken up by Biosphere–Transported by Water or Atmosphere–Sinks: Atmosphere, Deep Oceans, RocksReasons to be a "Carbon chauvinist".•Can bond to four neighboring atoms•Can bond to other carbon atoms, sharing one, two, or three electrons•These properties make it possible to form a vast array of organic molecules•No other element has these propertiesCarbon in the Earth•Volcanoes emit carbon dioxide•Carbonate rocks lock up carbon dioxide•Ancient biomass locked up carbon as coal, petroleum, natural gasCarbon in the BiospherePlants use sunlight, H2O, CO2 to create organic molecules:•6 H2O + 6 CO2 + energy  C6H12O6 (glucose) + 6O2 (toxic waste)Animals run the reactions in reverse:•C6H12O6 (glucose) + 6O2  6 H2O + 6 CO2 + energy•Also use organic molecules directly (vitamins)Carbon Cycles•Plant – Animal Cycle•Decay returns CO2 to atmosphere•Marine organisms fix CO2 in