BIO 111: Foundations of Biology Lecture 1: Water world

BIO111: Foundations of Biology Lecture 1: Water World

Lecture I: Water World 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 left our solar system.

~ 4.6 bya

Planets

“Dwarf” planets (smaller than the Moon)

Body Diameter Distance SUN 12 inches 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 0.02 in 4248 feet

Lecture I: Water World II. The Earth and its Neighbors A. Size and Temps -153 to 20oC -88 to 58oC 462oC

Earth Venus Mars CO2 0.035% 96% 95% N2 77% 3.5% 2.7% H2O 1% 0.01% Lecture I: Water World II. The Earth and Its Neighbors A. Size and Temps B. Atmospheric Composition Earth Venus Mars CO2 0.035% 96% 95% N2 77% 3.5% 2.7% H2O 1% 0.01% 0.007% Ar 0.93% 1.6% O2 21% trace

Lecture I: Water World 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: Water World III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure ATOMS: - nucleus: protons: charge = +1, mass = 1 neutrons: charge = 0, mass = 1 - shells/orbitals: electrons: charge = -1, mass = ~0

YOU AND ME ALL KNOWN MATTER IS MADE OF THESE INGREDIENTS: GALAXIES PLANETS OCEANS MOUNTAINS AIR PUPPIES VIRUSES YOUR FRIENDS YOU AND ME

An element’s “ATOMIC NUMBER” = # Of PROTONS III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure An element’s “ATOMIC NUMBER” = # Of PROTONS ATOMS: - nucleus: protons: charge = +1, mass = 1 neutrons: charge = 0, mass = 1 - shells/orbitals: electrons: charge = -1, mass = ~0 ELEMENTS: differ in # of protons

III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure ATOMS: - nucleus: protons: charge = +1, mass = 1 neutrons: charge = 0, mass = ~1 - shells/orbitals: electrons: charge = -1, mass = ~0 ELEMENTS: differ in # of protons ISOTOPES: differ in number of neutrons (and mass)

III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure ATOMS: - nucleus: protons: charge = +1, mass = 1 neutrons: charge = 0, mass = 1 - shells/orbitals: electrons: charge = -1, mass = ~0 ELEMENTS: differ in # of protons ISOTOPES: differ in number of neutrons (and mass) IONS: differ in number of electrons (and charge) 11 P 11 N 11 e- 11 P 11 N 10 e- Charge = 0 Charge = +1

H2, O2, CO2, H2O, C6H12O6, proteins, DNA, etc… III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure BONDS: Interactions between atoms, forming molecules: H2, O2, CO2, H2O, C6H12O6, proteins, DNA, etc… CEMENT DNA

H2 Oxygen (Gas) = O2 O2, CO2, H2O, C6H12O6, proteins, DNA, etc… III. Why The Differences? A. The Effects of Liquid Water 1. Water’s molecular structure BONDS: Interactions between atoms, forming molecules: O2, CO2, H2O, C6H12O6, proteins, DNA, etc… - Covalent Bond: share electrons to fill outermost shell 2, 8, 8 (‘octet rule’) shared equally = non-polar 2e 8 protons 8 protons 2e H2

WATER = H2O O2, CO2, H2O, C6H12O6, proteins, DNA, etc… BONDS: Interactions between atoms, forming molecules: O2, CO2, H2O, C6H12O6, proteins, DNA, etc… - Covalent Bond: share electrons to fill outermost shell 2, 8, 8 (‘octet rule’) shared equally = non-polar shared unequally = polar (partial charges) WATER = H2O The eight oxygen protons exert a stronger attractive force on the shared electrons than the single proton in each hydrogen atom – ‘pulling’ the cloud of electronegativity off the hydrogen protons, revealing ‘a part’ of their positive charge, and giving the oxygen atom a partial negative charge. Water is a ‘polar’ molecule… with charged ‘poles’.

O2, CO2, H2O, C6H12O6, proteins, DNA, etc… BONDS: Interactions between atoms, forming molecules: O2, CO2, H2O, C6H12O6, proteins, DNA, etc… - Covalent Bond: share electrons to fill outermost shell - Ionic Bond: attraction between ions A salt crystal: IONIC BONDS between sodium and chloride ions

O2, CO2, H2O, C6H12O6, proteins, DNA, etc… BONDS: Interactions between atoms, forming molecules: O2, CO2, H2O, C6H12O6, proteins, DNA, etc… - Covalent Bond: share electrons to fill outermost shell - Ionic Bond: attraction between ions - Hydrogen Bonds: Weak attraction of partial charges

HYDROGEN BONDS IN THE THREE STATES OF WATER

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: Water World 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: Water World 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 into IONS 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…

pH scale is negative exponent… so water = 7.0 Lecture I: Water World 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 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

HCl (Hydrochloric acid) dissociates much more readily in solution. Lecture I: Water World 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 17+ 1+ HCl (Hydrochloric acid) dissociates much more readily in solution. 1 in 100 molecules are dissociated = 1 x 10-2 pH = 2.0

In presence of water, H+ replaces K+, Na+, and CA+2 CATION DISPLACEMENT H+ K+ K-Al-Si3O8 H-Al-Si3O8 Na-Al-Si3O8 Ca-Al-Si2O8 In presence of water, H+ replaces K+, Na+, and CA+2 These ions – “salts” – go into solution and are carried to the sea… Lecture I: Water World 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. Weathers rock, putting ions into solution 60% of Earth’s Crust: Feldspar Minerals

Lecture I: Water World 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. Weathers rock, putting ions in solution 5. Carbon dioxide reacts with water to form carbonic acid

Abiogenic Limestone Formation Bicarbonate ion Carbonic acid Carbonate ion From ‘weathering’ of feldspars Calcium Carbonate (limestone)

Earth Venus Mars CO2 0.035% 96% 95% Abiogenic Limestone Formation Bicarbonate ion Carbonic acid Carbonate ion Calcium Carbonate (limestone)

Limestone CaCO3 Lecture I: Water World III. Why The Differences? A. The Effects of Liquid Water B. Tectonic Activity and Subduction Limestone CaCO3

Where did all the Carbon Dioxide go? 1) Lithosphere Limestone and Dolomite

Lecture I: Water World III. Why The Differences? A. The Effects of Liquid Water B. Tectonic Activity and Subduction C. ???

Topical Review: - The age, formation, and current structure of the solar system - Atomic structure, the elements, and the periodic table - How atoms interact, through bonding, to form molecules and compounds - the structure and properties of water - how water is responsible for making Earth’s atmosphere different from that of Venus and Mars - two philosophical approaches used in science: the comparative method and reductionism