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Lecture I: The Living Planet I. Formation of the Solar System The Earth, from 6 billion kilometers, taken by the Voyager 1 space probe on Feb 14, 1990, as it leaves our solar system. Planets “Dwarf” planets (smaller than the Moon) Body Diameter SUN 12 inches Distance Mercury 0.04 in 41 feet Venus 0.10 in 77 feet Earth 0.11 in 107 feet Mars 0.06 in 163 feet Asteriod belt………………………………………. Jupiter 1.23 in 559 feet Saturn 1.00 in 1025 feet Uranus 0.40 in 2062 feet Neptune 0.39 in 3232 feet Pluto 4248 feet 0.02 in Lecture I: The Living Planet II. The Earth and its Neighbors A. Size and Temps -153 – 20oC -88 – 58oC 462oC Lecture I: The Living Planet II. The Earth and Its Neighbors A. Size and Temps B. Atmospheric Composition CO2 N2 H2O Ar O2 Earth 0.035% 77% 1% 0.93% 21% Venus 96% 3.5% 0.01% 0.007% trace Mars 95% 2.7% 0.007% 1.6% trace Lecture I: The Living Planet II. The Earth and Its Neighbors III. Why The Differences? A. The Effects of Liquid Water About 4.4 bya, the period of heavy asteroid bombardment ended, and water could collect at the surface without being vaporized by meteorite impacts. Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure Chemistry basics: 1. Atoms and subatomic particles 2. Molecules and covalent bonds 3. Polar covalent bonds Spatial Scales: Earth is ~4 x 107 m in circumference Smallest Mammal - Pygmy Shrew: 2 inches (5 x 10-2 m) Largest Animal Ever - Blue Whale: 100 feet (3 x 101 m) Human - 6 ft... 2 x 100 m 1. Individual: 2. 3. Organs: variable Cells: Liver Cell: 2 x 10-5 m (2/100ths of a mm) E. coli Bacterium: 2 x 10-6 (1/10th of a liver cell) Virus: 2.5 x 10-8 (1/100th of a bacterium) Organelles: Ribosome: 1.8 x 10-8 m Mitochondrion: 2.5 x 10-6 m (about bacteria sized) Molecules: Hemoglobin (average protein): 6.8 x 10-9 m (1/1000th of a bact.) Phospholipid: 3.5 x 10-9 m Amino Acid: 5.0 x 10-10 m Atoms: Carbon: 1 x 10-10 m (1/10,000,000,000 m - a ten billionth of a meter) (a ten millionth of a millimeter) (a ten thousandth the length of a liver cell) Nucleus: 2 x 10-15 m. 5 orders of magnitude smaller than the width of the atom!!! 4. 5. 6. 7. So, the nucleus is only 1/50,000th the width of the atom. Atoms are mostly space… matter is mostly space… In fact, a cubic centimeter of nuclear matter (no space) would weigh 230 million tons (Physics by J. Orear, 1979) Analogy: If a basketball 1 ft. in diameter represents the nucleus of an atom, the edge of the electron cloud would be about 5 miles away in either direction; the atom would be 10 miles wide (~ 50,000 ft.)… that’s a lot of empty space. Analogy: You and the Earth are separated by 7 orders of linear magnitude. A millimeter (about the size of a bold-faced period) and a carbon atom are separated by 7 orders of linear magnitude. So, to a carbon atom, the period is it's Earth.... mind blowing... B. Temporal Scales: 1. Age of Earth: 4.5 x 109 yrs (4.5 billion) 2. History of Life on Earth: 3.5 x 109 years 3. Oldest Eukaryotic Cells: 1.8 x 109 years 4. Oldest Multicellular Animals: 6.1 x 108 years 5. Oldest Vertebrates: 5.0 x 108 (500 million) 6. Oldest Land Vertebrates: 3.6 x 108 7. Age of Dinosaurs - Mesozoic: 240-65 million 8. Oldest Primates: 2.5 x 107 (25 million) 9. Oldest Hominids: 4.0 x 106 (4 million – 1/1000th of earth history) 10. Oldest Homo sapiens: 2.0 x 105 (200,000) 11. Oldest Art: 3.0 x 104 (30,000; 1/100,000th of Life's History) 12. Oldest Agriculture: 1.0 x 104 (10,000) 13. Oldest Organism: Bristlecone pines: 5 x 103 14. Human cell: brain/muscle 70 yrs Red Blood Cell - weeks Skin cell – days 15. Supply of ATP in cell - 2 seconds 16. Rates of chemical reactions - milliseconds (3.1 x 10-10 ms/year). The history of life, spanning billions of years, is dependent on reactions that occur at a temporal scale separated by 19 orders of temporal magnitude. Atoms and Bonds I. Atoms A. Matter 1. Elements are different forms of matter which have different chemical and physical properties, and can not be broken down further by chemical reactions. 2. The smallest unit of an element that retains the properties of that element is an atom. 3. Atoms are composed of protons and neutrons in the nucleus, orbited by electrons: Proton: in nucleus; mass = 1, charge = +1 - Defines Element Neutron: in nucleus; mass = 1, charge = 0 Electron: orbits nucleus; mass ~ 0, charge = -1 Atoms and Bonds I. Atoms A. Matter B. Properties of Atoms 1. Subatomic Particles Proton: in nucleus; mass = 1, charge = +1 - Defines Element Neutron: in nucleus; mass = 1, charge = 0 Electron: orbits nucleus; mass ~ 0, charge = -1 Orbit at quantum distances (shells) Shells 1, 2, and 3 have 1, 4, and 4 orbits (2 electrons each) Shells hold 2, 8, 8 electrons = distance related to energy Neon (Bohr model) Atoms and Bonds I. Atoms A. Matter B. Properties of Atoms 1. Subatomic Particles 2. Mass = protons + neutrons 8 O 15.99 Atoms and Bonds I. Atoms A. Matter B. Properties of Atoms 1. Subatomic Particles 2. Mass = protons + neutrons 3. Charge = (# protons) - (# electrons)... If charge = 0, then you have an ...ION Atoms and Bonds I. Atoms A. Matter B. Properties of Atoms 4. Isotopes - Atoms and Bonds I. Atoms A. Matter B. Properties of Atoms 4. Isotopes - 'extra' neutrons... heavier Some are stable Some are not... they 'decay' - lose the neutron These 'radioisotopes' emit energy (radiation) Atoms and Bonds I. Atoms A. Matter B. Properties of Atoms 4. Isotopes - 'extra' neutrons... heavier Some are stable Some are not... they 'decay' - lose the neutron These 'radioisotopes' emit energy (radiation) This process is not affected by environmental conditions and is constant; so if we know the amount of parent and daughter isotope, and we know the decay rate, we can calculate the time it has taken for this much daughter isotope to be produced. Atoms and Bonds I. Atoms A. Matter B. Properties of Atoms 4. Isotopes - 'extra' neutrons... heavier Gamma decay - neutron emits energy as a photon - no change in neutron number, mass, or element. Alpha decay - loss of an alpha particle (2 protons and 2 neutrons) from the nucleus. This changes the mass and element. (Uranium with 92 protons decays to Thorium with 90 protons) Beta decay - a neutron changes to a proton, and an electron is emitted. This changes only the element (determined by the number of protons), but not the mass. (C14 decays, neutron changes to proton, and N14 is produced) Lecture I: The Living Planet I. II. The Earth and Its Neighbors Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure 2. Water is called the “universal solvent” - ions and polar compounds dissolve in water Charged regions of a glucose molecule Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure 2. Water is known as the “universal solvent” Chlorine (Cl): 17P, 17eChemistry basics: 1. Atoms and subatomic particles 2. Molecules and covalent bonds 3. Polar covalent bonds 4. Ionic bonds and compounds - transfer creates atoms with unequal number of protons and electrons. These are “ions” Cl-, Na+ Sodium (Na): 11P, 11e Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure 2. Water is called the “universal solvent” - ions and polar compounds dissolve in water Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure 2. Water is called the “universal solvent” - ions and polar compounds dissolve in water - Rocks are composed of ionic compounds (minerals) - So many rocks dissolve Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure 2. Water is called the “universal solvent” 3. Water dissociates Hydronium: Oxygen: 8 protons, 2e first shell, 8 second 3 H: 3 protons Total: 11 protons, 10 electrons = +1 charge (will readily give up H+ ion Hydronium can give up an H+, so same net effect as above… Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure 2. Water is called the “universal solvent” 3. Water dissociates Chemistry basics: 1. Atoms and subatomic particles 2. Molecules and covalent bonds 3. Polar covalent bonds 4. Ionic bonds and compounds - transfer creates atoms with unequal number of protons and electrons. These are “ions” Cl-, Na+ 5. pH, acids, and bases In pure water, 1 in 10,000,000 (1 x 10-7) molecules will be dissociated at any one time The “power” (in terms of exponent) of Hydrogen… you can think of it as percent or proportion of H+. pH scale is negative exponent… so water = 7.0 Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water 17+ 1+ 1. Water’s molecular structure 2. Water is called the “universal solvent” 3. Water dissociates Chemistry basics: 1. Atoms and subatomic particles 2. Molecules and covalent bonds 3. Polar covalent bonds 4. Ionic bonds and compounds - transfer creates atoms with unequal number of protons and electrons. These are “ions” Cl-, Na+ 5. pH, acids, and bases HCl (Hydrochloric acid) dissociates much more readily in solution. 1 in 100 molecules are dissociated = 1 x 10-2 pH = 2.0 Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure 2. Water is called the “universal solvent” 3. Water dissociates Chemistry basics: 1. Atoms and subatomic particles 2. Molecules and covalent bonds 3. Polar covalent bonds 4. Ionic bonds and compounds - transfer creates atoms with unequal number of protons and electrons. These are “ions” Cl-, Na+ 5. pH, acids, and bases CATION DISPLACEMENT Feldspar Minerals (60%) K-Al-Si3O8 Na-Al-Si3O8 Ca-Al-Si2O8 In presence of water, H+ replaces K+, Na+, and CA+2 Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure 2. Water is called the “universal solvent” 3. Water dissociates 4. Carbon dioxide reacts with water to form carbonic acid Abiogenic Limestone Formation Bicarbonate ion Carbonic acid Carbonate ion Calcium Carbonate (limestone) Abiogenic Limestone Formation Earth CO2 0.035% Venus 96% Mars Bicarbonate ion 95% Carbonic acid Carbonate ion Calcium Carbonate (limestone) Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water B. Tectonic Activity and Subduction Limestone Lecture I: The Living Planet Coccolithophore (single celled marine algae) III. Why The Differences? A. The Effects of Liquid Water B. Tectonic Activity and Subduction C. The Effects of LIFE 1. Biogenic Limestone Formation “Coquina” Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water B. Tectonic Activity and Subduction C. The Effects of LIFE 1. Biogenic Limestone Formation SHELLS Settled out 400 m 4 um (4/1000’s of a mm; 250,000 per meter) 100,000,000 deep, but they are crushed, so it’s actually more… 400 m 4 um (4/1000’s of a mm; 250,000 per meter) 100,000,000 deep, but they are crushed, so it’s actually more… Little things, big effects… Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water B. Tectonic Activity and Subduction C. The Effects of LIFE 1. Biogenic Limestone Formation 2. Photosynthesis Photosynthetic bacteria Overview: A. Step One: Transferring radiant energy to chemical energy eEnergy of photon Transferred to an electron e- Overview: A. Step Two: storing that chemical energy in the bonds of molecules eATP e- ADP +P Light Dependent Reaction Electron becomes trapped in a chemical bond (phosphate bond) between PO4 and ADP Overview: A. Step Two: storing that chemical energy in the bonds of molecules eATP eLight Dependent Reaction Where do the electrons come from? ADP +P Overview: A. Step Two: storing that chemical energy in the bonds of molecules eATP ADP +P eLight Dependent Reaction Where do the electrons come from? Photosynthetic organisms split WATER: to harvest electrons 2 (H-O-H) 2O + 4H+ + 4eO2 Overview: A. Step Two: storing that chemical energy in the bonds of molecules eATP ADP +P e- BUT… P~P bonds are weak. To “store” this energy, stronger, more stable bonds need to be made. ATP bonds are broken and C-C bonds are made. Light Dependent Reaction Where do the electrons come from? Photosynthetic organisms split WATER: 2 (H-O-H) 2O + 4H+ + 4eO2 Overview: A. Step Two: storing that chemical energy in the bonds of molecules e- C6 (glucose) ATP ADP +P eLight Dependent Reaction 6 CO2 Light Independent Reaction Where do the electrons come from? Photosynthetic organisms split WATER: 2 (H-O-H) 2O + 4H+ + 4eO2 Lecture I: The Living Planet III. Why The Differences? A. The Effects of Liquid Water B. Tectonic Activity and Subduction C. The Effects of LIFE 1. Biogenic Limestone Formation 2. Photosynthesis Little things (photosynthetic bacteria), big effects… CO2 N2 H2O Ar O2 Earth Venus Mars 0.035% 77% 1% 0.93% 96% 3.5% 0.01% 0.007% 95% 2.7% 0.007% 1.6% trace trace 21% Where did all the CO2 go? The atmosphere is no longer a major “reservoir” for carbon on our planet. Where did all the CO2 go? The atmosphere is no longer a major “reservoir” for carbon on our planet. Most has been transferred to the lithosphere by limestone formation Where did all the CO2 go? The atmosphere is no longer a major “reservoir” for carbon on our planet. Most has been transferred to the lithosphere by limestone formation And there is nearly as much carbon In living terrestrial biomass as in the atmosphere Where did all the CO2 go? The atmosphere is no longer a major “reservoir” for carbon on our planet. Most has been transferred to the lithosphere by limestone formation And there is nearly as much carbon In living terrestrial biomass as in the atmosphere More in the entire biosphere, including decomposing material in soils and marine life How do we know that oxygen wasn’t always present in the Earth’s atmosphere? Maybe Earth is just different from Venus and Mars… Banded iron formations are first seen 2.5 billion years ago, showing that oxygen must have been present in the ocean to precipitate iron out of solution as iron oxides in sedimentary strata. There absence in older strata means that oxygen was not present in appreciable amounts. The Carboniferous “Pulse” 1. Terrestrial plants were radiating, sucking up CO2 and producing O2. 2. Huge expanses of swamp forests dominated the equatorial zone. Photosynthetic rates were high, but the trees were preserved under sediments when they died and fell…. Creating our coal deposits. Photosynthesis produced lots of O2, but with less decay, it stayed in the air instead of being breathed in and used by decomposing bacteria. The K-T Extinction affected atmospheric oxygen levels as plants went extinct and terrestrial photosynthetic activity declined. And today? The Earth is a living planet… it breathes… 21% = 210,000,000 ppm, So a decline of 70 ppm is not dramatic.