1. Bellringer
List an example of an acid or base you
are familiar with in everyday life.
What do you know about the pH scale?

2. Agenda
 Collection Time
 Book Project & Macromolecule notes
 Candy Molecules lab
 Quick Experiment: Milk and Vinegar
 Guided Notes: pH & the Effect on Protein
 Compare Acids and Bases
 Review the use of pH scale
 Describe how changes in pH affect proteins

3. Properties of Acids
Sour taste
Corrosive to metals
Burns the Skin

4. Examples of Acids
Acetic Acid in Vinegar
Citric Acid in Oranges and
Lemons
Hydrochloric Acid dissolves
food in your stomach

5. Properties of Bases
Bitter Taste
Feel “Soapy”
Will irritate your skin

6. Examples of Bases
Milk of Magnesia
Bleach
Many Soaps

7. Acid/Base Chemistry
Acids release Hydrogen ions [H+]
when mixed with water.
Bases absorb Hydrogen ions [H+]
when mixed with water.

8. Neutralizations
Since Acids produce [H+] and Bases
absorb [H+], it is possible for acids
and bases to cancel one another.
When acids and bases cancel out it
is called Neutralizing

9. pH Scale
The strength of Acids and Bases
is measured using the pH scale
Scale goes from 0 to 14
 ACIDS = below 7
 NEUTRAL = exactly 7
 BASES = above 7

10. pH and Strength
The further an acid or base is from 7,
the stronger it is.
Examples
 Lemon Juice (2.0) is a stronger acid than Beer
(4.0) because a pH of 2 is farther from 7.
 Ammonia (11.0) is a stronger base than Baking
Soda (8.3) because a pH of 11 is farther from 7.

11. BrainPOP: Acid/Base

12. Protein Folding
Proteins are long chains of amino acids.
These chains bend and fold into a certain
shape that allows them to perform their job.
The shape of the protein is held together by
bonds between amino acids on different parts
of the chain.

14. Protein Structure Video Clip

15. How Acids Denature Proteins
 Acids destroy proteins by “denaturing” them. This
means that the protein gets unwrapped and the
shape is destroyed.
 Acids can unwind proteins because the H+
[Hydrogen ions] interfere with the bonds that hold
the protein together.
 For this reason, it is important for living things to
maintain a consistent pH level in bodily fluid. For
example, human blood must stay at a pH of 7.4

16. H+
H+
H+
H+
H+

17. Explain what caused the milk to curdle. . .

18. Assignments
12 Review Questions
Using pH to identify liquids
Students should complete their
Quarterly Assessment if not finished
yesterday.