1. Biology 12
Biological Molecules

2. Cheat Sheet prefix/suffix
-ology = the study of
Cyto-/cyte = cell
Hydro-/hydrate = water
Lyso- = split
Lysis = break apart
Pod/ped = foot
Thermo = temperature
Phobia/-phobic = fear/hating
-phylic / -philia = loving
Poly = many
Iso = same
Soma - / -some = body
Chrome=colour

3. Atomic Bonding Ionic Bonding Covalent Bonding
Polar Bonds/ Hydrogen Bonds/ H-Bonds

4. Ionic Bonding A metal + non-metal
Metal will give all e- in its outer shell to a non- metal so that both have a full shell

5. Covalent Bonding 2 non-metals will share electrons
Both atoms share the electrons equally (non-polar, hydrophobic)
Because the e- are shared equally by both atoms, the molecule is electrically “neutral”
The shared electrons are attracted equally to both nuclei because they have the same charge
The electrons are not shared equally (polar, hydrophilic)

6. Polar Bonds/ Hydrogen Bonds
Bond between 2 polar molecules
The positive end of one is attracted to the negative end of the other
Ie: the bond that hold the water molecules together

7. Other Notes Polar mixes with Polar Non-Polar mixes w/ Non-Polar
Ie: Water + Sugar
Non-Polar mixes w/ Non-Polar
Gasoline + oil
Polar and Non-Polar do NOT mix
Water and Oil

8. Acid, Bases and Buffer
Polarity can cause some molecules to split apart or DISSOCIATE when mixed with water
Ie: H2O -> H+ + OH-
Note: [ ] Concentration
Ie: [salt] = salt concentration

9. Acid, Bases and Buffer
Acids- any compound that dissociates in water to release H+ ions
Bases – any compounds that dissociates in H2O to release OH- ions
[OH]>[H+]
When [H-] and [OH-] are equal to each other, what is the solution called?

10. Buffer
Compounds that pick up excess H+ or OH- to maintain a constant pH of a solution
Essential to living things
In humans, buffers help us maintain homeostasis
A common buffer that we have is HCO3-

11. 2 min break