1. Basic Chemistry
Department of Biology, WCU

2. Matter
Elements
85% in nature
Most common C, O2, H, N2

3. Elements Composed of atoms Protons, neutrons, electrons physical
chemical
Protons, neutrons, electrons

4. Identifying elements
Number of particles

5. Identifying elements Protons: identify Electrons: chemical properties
3 measures
Atomic number (2He)
Mass number (4He)

6. Identifying elements
3 measures
Isotope
- Atomic weight (H+ = 1.008)

7. Bonding Molecule H + H = H2 Compound = 2H + O = H2O
Compound = molecule x 2

8. Chemical bonding Energy of electrons Electron shells Valence shell
1 = 2 e-s, 2 = 8 e-s, 3 = 18 e-s
Valence shell

9. Chemical bonding 1. Ionic bonds
Electron donor (cation) and acceptor (anion)

10. Chemical bonding 2. Covalent bonds Electron sharing (H+)
Single, double and triple bonds

11. Chemical bonding
2. Covalent bonds
double bonds

12. Covalent bonds
Non-polar: equal sharing
Polar (H2O is a dipole)

13. Covalent bonds
3. Hydrogen bonds
Weak (water beading)

14. Elements in biology Most are C, H, N, O Organic
Inorganic (water, salt, acids)

15. Inorganic compounds Water High heat capacity
High heat of vaporization (sweating)
Solvent
dissociation (digestion)
hydration
Cushioning (cerebral fluid)

16. Acid-base balance Acid Base Releases H + (HCl = H+ + Cl-, digestion)
Takes up H+ (NaOH = Na + + OH- = H2O)

17. Acid-base balance pH Acidity [H+] High pH (alkaline - proton acceptor)
Low pH (acid - proton donor)
Scale
Logarithmic

18. pH scale
Acidic pH 1 = [H+] 100
Basic pH 14 = [H+] 10-14

19. Buffer Release H+ if pH increases, bind H+ if pH decreases
e.g. proteins
Blood pH