1. Chemical Basis of Life Chapter 2

2. Chemistry Matter is made up of separate chemical components –Chemistry = Interactions between atoms/molecules

3. Sub-cellular concepts Matter Atoms Elements Natural elements –About 25 essential for life –H,O,N,C = 96% of human body –Trace elements

4. Atomic Structure 3 Basic subatomic particles. –Proton –Electron –Neutrons Atomic Number Atomic Mass

5. Periodic Table of Elements

6. Isotopes different forms of same element. Same number of Protons, but different mass Radioactive Isotopes

7. Electrons (e - ) Arranged in shells Valence Hydrogen (H) Atomic number = 1 Electron Carbon (C) Atomic number = 6 Nitrogen (N) Atomic number = 7 Oxygen (O) Atomic number = 8 Outermost electron shell (can hold 8 electrons) First electron shell (can hold 2 electrons) Reactivity

8. Chemical Bonding – Ionic Bonds Form between Ions of opposite charge NaCl –One atom gives up e - (cation). –One atom recieves e - (anion). –Results in filled outer shells for both.

9. Chemical Bonding – Ionic Bonds

10. Ionic Bond Animation

11. Chemical Bonding: Covalent Bonds Result from electron sharing. –1 or more pairs of outer shell electrons. –Number of possible bonds = number needed to fill outer shell.

12. Covalent Bond Animation

13. Water Polar molecule –Electronegativity –Polar covalent bonds

14. Chemical Bonding – Hydrogen Bonds Attraction between the (+) and (-) ends of a molecule Weak bonds Hydrogen = positive end Oxygen = negative end

15. Hydrogen Bonding Animation

16. Unique Properties of Water Cohesion Adhesion Resistant to temperature change

17. Molecular Structure Structural formula Ball and stick

18. More Definitions Solutions –Solvent –Solute Aqueous solution = Water is the solvent –Water = Universal solvent –Results from the Polarity

19. pH (potential of Hydrogen) H 2 O dissociates into H + and OH - (hydroxide) ions –Acids –Bases pH scale

20. pH Scale

21. Chemical Reactions Processes producing chemical changes in matter –Reactants –Products Matter cannot be created or destroyed Energy flow 2 H 2 O2O2 2 H 2 O

22. Types of Chemical Reactions Oxidation-Reduction (redox) –Ex. C 6 H 12 O 6 + 6O 2  6CO 2 + 6 H 2 O + ATP