BIOL 120 1st Edition Lecture 3Outline of Last Lecture II. Hierarchy of living systems (finished)III. Process of science & scientific methoda. Deductive reasoning, Inductive reasoning, observation, hypothesis, prediction, IV. Cells & Cell Theory a. Cell Theory, CellV. Evolution and Natural Selectiona. Evolution, Phylogenetic tree, Natural selection, fitness, adaptation, selective adaptation VI. Interpreting the tree of life & Taxonomy a. Phylogenetic tree, Taxonomy, phylum, genus, speciesVII. Summary of chapter 1 Outline of Current Lecture II. Basic Atomic Structurea. Matter, Element, Atoms, Protons, Neutrons, Electrons, Molecules, Energy, Chemical Energy, Thermodynamics, Atomic Number, Atomic Mass, Isotope, III. Chemical Bondsa. Valence electrons, Valence, Chemical Reaction, Covalent Bond, Ion, Cation, Anion, Ionic Bond IV. Representing Molecules a. Molecular formulas, Structural formulas, Ball and stick models, Space filling models, CPK coloring modelsCurrent LectureII. Basic Atomic StructureA. chemical reactions are happen 24/7 in our bodies to turn food into energyThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.1. Complex molecules are metabolized to release energy to the bodyB. Matter: anything that occupies space and has mass (solid, liquid, or gas)1. i.e. rocks, metals, airC. Element: a substance that can’t be broken down into another substance by chemical reactions1. 25 elements are essential for life  provide nutrition for bodily functions a. Carbon (proteins), Hydrogen, Oxygen, Nitrogen (DNA) 95% of the elements living matter usesb. Phosphorus (ATP), Sulfur (amino acids), calcium (bone structure), potassium (needed for muscle movement) + few others  last 5%c. The body also requires a few trace elements: needed for enzyme activity (Iron, Iodine, etc.)2. Atomic Numbera. Atomic number: the number of protons in the nucleus i. i.e. Hydrogen has 1 proton  Atomic number is 1b. Atomic mass: the number of protons and neutrons i. isotope: an atom with the same number of protons, but a different number of neutrons (number of electrons are similar in all cases)a). i.e. Carbon has 6 p and 6 n  At. Wt. = 12b). Carbon has 6 p and 8n  At. Wt. = 14D. Atoms1. Composed of:a. Protons: positively charged particlesb. Neutrons: neutral particlesi. Protons and neutrons are found in the nucleusc. Electrons: negatively charged particles i. Electrons surround the nucleus in orbitals E. Molecules1. Molecule: a substance made from two or more atoms of similar or different types (O2, H2O, NaCl)a. form when atoms bond to each other 2. Water is the most important for lifea. It is highly polar forms hydrogen bonds (connects DNA) i. This makes water an extremely efficient solvent (ability to dissolve things)F. Energy1. Energy: is the capacity to do work or supply heat, and can be 1. Stored potential or 2. Active motion a. Chemical energy = potential energy that is stored in chemical bondsi. When ATP breaks down this is what provides the body energy from foodii. If these reactions are spontaneous  lead to lower potential energy and higher entropyiii. If non spontaneous  require an input of energyb. Most important compounds in organisms contain carbon G. Thermodynamics1. First Law: energy cannot be created or destroyed2. Second Law: spontaneous natural processes increase entropy overall H. Atomic Number1. Atomic number: the number of protons in the nucleusa. i.e. Hydrogen has 1 proton  Atomic number is 12. Atomic mass: the number of protons and neutrons a. isotope: an atom with the same number of protons, but a different number of neutrons (number of electrons are similar in all cases)i. i.e. Carbon has 6 p and 6 n  At. Wt. = 12ii. Carbon has 6 p and 8n At. Wt. = 14III. Chemical Bonds 1. Atomic mass and atomic number describe how an element will interact with another element (will it gain, lose, or share an electron to be stable)a. left side of periodic table tends to give up an electron and right side tends to gain oneb. This electron activity is the basis for organization of materials and flow of energy through living world 2. Electron arrangement around the nucleusa. They move in regions called orbitals each orbital can hold up to 2 electrons i. these orbitals are grouped in levels called electron shells a). i.e. Shell 1= 1 orbital  2 electronsShell 2= 4 orbitals  8 electrons – 11 electrons:  2 in shell 1, 8 in shell 2, 1 in shell 3  unbalanced and will gain or lose ii. Valance electrons: electrons in the outermost shell iii. Valance: number of unpaired electrons in an atoma). determines the number of bonds an element can make  carbon has 4 valences therefore it can make 4 bonds3. Chemical reactionA. Chemical reaction: when an atom gives up, shares, or gains one or more electrons with another atom 1. Atoms are most stable when each electron orbital is filledB. Covalent Bond: each atom’s unpaired valence electrons are shared by both nuclei to fill their orbital 1. Known as molecules 2. Electrons are not always shared equally  An atom with high electronegativity will hold the electrons closer giving it a partial negative change and the weaker atom a partial positive charge a) Non polar covalent bond: equal electronegativityb) Polar covalent bond: unequal electronegativityC. Ionic Bond1.Ion: an atom or molecule that carries a charge2. Cation: an atom that loses an electron and becomes positively charged3. Anion: an atom that gains and electron and becomes negatively charged4. Ionic Bond: results from the attraction of a cation and anionIV. Representing MoleculesA. Molecular formulas: indicate the numbers and types of atoms in a molecule1. i.e. H2O, CH4 B. Structural formulas: indicate which atoms are bonded together and whether the bonds are single, double, or triple C. Ball and stick models and space filling models: show 3D geometry D. CPK coloring: a popular color convention for distinguishing atoms of different chemical elements in molecular