1. Some Essential Chemistry
…for all the Biologists who aren’t Chemists 

2. Oxidation & Reduction Reactions (Re-dox)
Involves the movement of ELECTRONS (doesn’t always occur in reactions with oxygen)
LEO the lion says GER
LEO = Lose Electrons Oxidized
GER = Gain Electrons Reduced

3. Example NaCl  Na+ + Cl- Which element has been oxidized? How?
Which element has been reduced? How?
a. Na was oxidized as chlorine received an electron from sodium in the ionic bond of NaCl
b. Cl was reduced as it received an electron from Na

4. Re-dox reactions involving covalent compounds
Oxidation is the loss of HYDROGEN atoms and reduction is the gain of H atoms
1 hydrogen atom contains 1 proton & 1 electron, so…
If a molecule loses an H atom, it has lost an electron
If a molecule gains an H atom, it has gained an electron
These types of re-dox reactions occur a lot
in cellular reactions!

5. Dissociation of Acids & Bases
When we break a molecule apart, we have dissociated it (ex. NaCl  Na+ + Cl-)
When acids dissociate, hydrogen (H+) ions are released
When bases dissociate, hydroxide (OH-) ions are released

6. An Acid… Will form H+ ions in solution Tastes sour
Has a pH less than 7
Ex. HCl, lemon juice, vinegar

7. A Base… Will form OH- ions in solution Tastes bitter
Has a pH of more than 7
Ex. NaOH, ammonia, household cleaners

8. pH
Explain what is meant by the term pH. How can pH be raised or lowered? pH measures the level of acidity or basicity (alkalinity) of a solution. Increasing OH- ions will raise pH (more basic) whereas increasing H+ ions will lower pH (more acidic).

9. Buffers
What is the purpose of a buffer? Buffers are chemical combinations that take up excess H+ or OH- ions in order to keep the pH of a solution CONSTANT. This is important for maintaining pH & homeostasis in living things!!!