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)

BodyDiameterDistance SUN12 inches Mercury0.04 in41 feet Venus0.10 in77 feet Earth0.11 in107 feet Mars0.06 in163 feet Asteriod belt………………………………………. Jupiter1.23 in559 feet Saturn1.00 in1025 feet Uranus0.40 in2062 feet Neptune0.39 in3232 feet Pluto0.02 in4248 feet

Lecture I: The Living Planet II. The Earth and its Neighbors A. Size and Temps -153 – 20 o C-88 – 58 o C462 o C

EarthVenusMars CO %96%95% N2N2 77%3.5%2.7% H2OH2O1%0.01%0.007% Ar0.93%0.007%1.6% O2O2 21%trace Lecture I: The Living Planet II. The Earth and Its Neighbors A. Size and Temps B. Atmospheric Composition

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 10 7 m in circumference 1.Individual: Smallest Mammal - Pygmy Shrew: 2 inches (5 x m) Largest Animal Ever - Blue Whale: 100 feet (3 x 10 1 m) Human - 6 ft... 2 x 10 0 m 2. Organs: variable 3. Cells: Liver Cell: 2 x m (2/100ths of a mm) E. coli Bacterium: 2 x (1/10th of a liver cell) Virus: 2.5 x (1/100th of a bacterium) 4. Organelles:Ribosome: 1.8 x m Mitochondrion: 2.5 x m (about bacteria sized) 5. Molecules: Hemoglobin (average protein): 6.8 x m (1/1000th of a bact.) Phospholipid: 3.5 x m Amino Acid: 5.0 x m 6. Atoms: Carbon: 1 x 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) 7.Nucleus: 2 x m. 5 orders of magnitude smaller than the width of the atom!!!

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 10 9 yrs (4.5 billion) 2. History of Life on Earth: 3.5 x 10 9 years 3. Oldest Eukaryotic Cells: 1.8 x 10 9 years 4. Oldest Multicellular Animals: 6.1 x 10 8 years 5. Oldest Vertebrates: 5.0 x 10 8 (500 million) 6. Oldest Land Vertebrates: 3.6 x Age of Dinosaurs - Mesozoic: million 8. Oldest Primates: 2.5 x 10 7 (25 million) 9. Oldest Hominids: 4.0 x 10 6 (4 million – 1/1000 th of earth history) 10. Oldest Homo sapiens: 2.0 x 10 5 (200,000) 11. Oldest Art: 3.0 x 10 4 (30,000; 1/100,000th of Life's History) 12. Oldest Agriculture: 1.0 x 10 4 (10,000) 13. Oldest Organism: Bristlecone pines: 5 x 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 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 O

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.The Earth and Its Neighbors II.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” 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+ Chlorine (Cl): 17P, 17e- 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 can give up an H+, so same net effect as above… 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

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 ) 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 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 pH =

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-Si 3 O 8 Na-Al-Si 3 O 8 Ca-Al-Si 2 O 8 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 Carbonic acid Bicarbonate ion Carbonate ion Calcium Carbonate (limestone)

Abiogenic Limestone Formation Carbonic acid Bicarbonate ion Carbonate ion Calcium Carbonate (limestone) EarthVenusMars CO %96%95%

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 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” Coccolithophore (single celled marine algae)

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

4 um (4/1000’s of a mm; 250,000 per meter) 400 m 100,000,000 deep, but they are crushed, so it’s actually more…

4 um (4/1000’s of a mm; 250,000 per meter) 400 m 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 Energy of photon e- Transferred to an electron

Overview: A. Step Two: storing that chemical energy in the bonds of molecules e- ATP ADP +P Light Dependent Reaction Electron becomes trapped in a chemical bond (phosphate bond) between PO 4 and ADP

Overview: A. Step Two: storing that chemical energy in the bonds of molecules e- ATP ADP +P Where do the electrons come from? Light Dependent Reaction

Overview: A. Step Two: storing that chemical energy in the bonds of molecules e- ATP ADP +P Where do the electrons come from? Photosynthetic organisms split WATER: to harvest electrons 2 (H-O-H) 2O + 4H + + 4e- O2O2 Light Dependent Reaction

Overview: A. Step Two: storing that chemical energy in the bonds of molecules e- ATP ADP +P Where do the electrons come from? Photosynthetic organisms split WATER: 2 (H-O-H) 2O + 4H + + 4e- O2O2 Light Dependent Reaction 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.

Overview: A. Step Two: storing that chemical energy in the bonds of molecules e- ATP ADP +P Where do the electrons come from? Photosynthetic organisms split WATER: 2 (H-O-H) 2O + 4H + + 4e- O2O2 6 CO 2 C 6 (glucose) Light Independent Reaction Light Dependent Reaction

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 EarthVenusMars CO %96%95% N2N2 77%3.5%2.7% H2OH2O1%0.01%0.007% Ar0.93%0.007%1.6% O2O2 21%trace Little things (photosynthetic bacteria), big effects…

Where did all the CO 2 go? The atmosphere is no longer a major “reservoir” for carbon on our planet.

Where did all the CO 2 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 CO 2 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 CO 2 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

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. How do we know that oxygen wasn’t always present in the Earth’s atmosphere? Maybe Earth is just different from Venus and Mars…

The Carboniferous “Pulse”

1.Terrestrial plants were radiating, sucking up CO 2 and producing O 2. 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 O 2, 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.