1. Lecture #1 ~ Date__________ zChapter 1: Themes in the Study of Life zChapter 2: Chemical Context of Life zChapter 3: Water and the Fitness of the Environment

2. Themes of AP Biology Evolution: Organisms, molecules, and the Earth change over time and this is the fundamental idea behind all studies of biology. Science as a Process : Inquiry and ongoing need for better explanations are the root of all scientific studies. Energy Transfer: Energy provided by the sun cycles through molecules and organisms. Continuity and Change: Life and life processes have the ability to be consistent and stay the same and to change over time to adapt. Relationship of Structure to Function: The structure of a molecule, part, or organism is integral to the functioning of that aspect of life. Regulation: Organisms have the ability to adapt to changes in the environment. Interdependence in Nature: Abiotic factors and other organism exert constant influence on an organism. Science, Technology, and Society: We use technology to study life and we use the study of life to improve technology and society.

3. Other concepts in Biology zEmergent Properties: smaller parts work together and while they often retain their original properties, there are also new properties based on their synergy. zThe Cell~ all organism’s basic structure zHeritable Information~ DNA zReproduction: Organisms reproduce to continue their species through time. This can be asexual or sexual in nature. zNatural Selection: As populations evolve sometimes the cause is due to differential reproductive success which leads to changes in the population to be genetically more like the successful organisms.

4. Chemical Context of Life zMatter (space & mass) zElements and compounds zThe atom (element) zThe molecule (compound) zAtomic number (# of protons); mass number (protons + neutrons): defines what element a substance is. zIsotopes (different # of neutrons); radioactive isotopes (nuclear decay) zEnergy (ability to do work); energy levels (electron states of potential energy) Includes Chemical energy stored in bonds.

5. Radioactive isotopes uses zhttp://www.chem.duke.edu /~jds/cruise_chem/nuclear /uses.htmlhttp://www.chem.duke.edu /~jds/cruise_chem/nuclear /uses.html zhttp://www.ausetute.com.a u/nuclesum.htmlhttp://www.ausetute.com.a u/nuclesum.html zCAT scan vs. PET scan

6. Chemical Bonding zCovalent zDouble covalent zNonpolar covalent zPolar covalent zIonic zHydrogen zDispersion forces

7. Covalent Bonding zSharing pair of valence electrons zNumber of electrons required to complete an atom’s valence shell determines how many bonds will form zEx: Hydrogen & oxygen bonding in water; methane

8. Polar/nonpolar covalent bonds zElectronegativity attraction for electrons zNonpolar covalent electrons shared equally Ex: diatomic H and O Ex: C and H in fats/lipids zPolar covalent one atom more electronegative than the other (small charges) Ex: water

9. Ionic bonding zHigh electronegativity difference strips valence electrons away from another atom zElectron transfer creates ions (charged atoms) zCation (positive ion); anion (negative ion) zEx: Salts (sodium chloride)

10. Hydrogen bonds zHydrogen atom covalently bonded to another atom with a different electronegativity. zThe Hydrogen atom has a slight positive charge as the electron is spending more time with the other atom. zThe positively charged hydrogen atom of one water is attracted to the negatively charged atom on the other molecule.

11. Hydrogen Bonds continued zWeak (1/100 of a covalent bond) zTemporary zPlentiful zCommon in water

12. Dispersion forces zWeak interactions between molecules or parts of molecules that are brought about by localized change fluctuations. zDue to the fact that electrons are constantly in motion and at any given instant, ever-changing “hot spots” of negative or positive charge may develop. zVery weak and temporary

13. Acid/Base & pH zDissociation of water into a hydrogen ion and a hydroxide ion zAcid: increases the hydrogen concentration of a solution zBase: reduces the hydrogen ion concentration of a solution zpH: “power of hydrogen” zBuffers: substances that minimize H+ and OH- concentrations (accepts or donates H+ ions)

14. pH scale: pH = -log 10 [H + ] Table 2.2 pH Scale The hydrogen ion and hydroxyl ion concentrations are given in moles per liter at 25°C. pH[H+][OH-] 0(10 0 )1.00.00000000000001(10 -14 ) 1 (10 -1 ) 0.10.0000000000001(10 -13 ) 2 (10 -2 ) 0.010.000000000001(10 -12 ) 3 (10 -3 ) 0.0010.00000000001(10 -11 ) 4 (10 -4 ) 0.00010.0000000001(10 -10 ) 5 (10 -5 ) 0.000010.000000001(10 -9 ) 6 (10 -6 ) 0.0000010.00000001(10 -8 ) 7 (10 -7 ) 0.0000001 (10 -7 ) 8 (10 -8 ) 0.000000010.000001(10 -6 ) 9 (10 -9 ) 0.0000000010.00001(10 -5 ) 10 (10 -10 ) 0.00000000010.0001(10 -4 ) 11(10 -11 )0.000000000010.001(10 -3 ) 12 (10 -12 ) 0.0000000000010.01(10 -2 ) 13(10 -13 )0.00000000000010.1(10 -1 ) 14(10 -14 )0.000000000000011.0(10 0 ) pH = -log 10 [H + ]

15. Buffering: Bicarbonate Ion zBicarbonate Ion, HCO 3 - is the most common form in blood and ocean. zIt can absorb or release an H+ based on environment. This allows the system to buffered from pH change

16. Acid Precipitation zCarbon dioxide + water makes carbonic acid (pH = 5.6), so “clean” rain water has a pH of 5.6 as carbon dixoide is plentiful. zNOx and SOx are released in exhausts from cars and coal plants. They make sulfuric acid and nitric acid as they blow away which are much stronger acids. zAcid snow and fog become more concentrated as the water evaporates leaving behind a more concentrated acid.

17. Water zPolar~ opposite ends, opposite charges zCohesion~ H+ bonds holding molecules together zAdhesion~ H+ bonds holding molecules to another substance zSurface tension~ measurement of the difficulty to break or stretch the surface of a liquid zSpecific heat~ amount of heat absorbed or lost to change temperature by 1oC zHeat of vaporization~ quantity of heat required to convert 1g from liquid to gas states zDensity……….

18. Density zLess dense as solid than liquid zDue to hydrogen bonding zCrystalline lattice keeps molecules at a distance