1. Enzymes

2. What Are Enzymes? Most enzymes are Proteins
Act as Catalyst to accelerates a reaction
Not permanently changed in the process

3. Enzymes Are specific for what they will catalyze Are Reusable
End in –ase
-Sucrase
-Lactase
-Maltase

4. Salivary Amylase Demo
Starch
Glucose

5. How do enzymes Work?
Enzymes lower activation energy

6. A catalyst lowers activation energy.
Catalysts are substances that speed up chemical reactions.
decrease activation energy
increase reaction rate

7. Enzymes Without Enzyme With Enzyme Free Energy
Progress of the reaction
Reactants
Products
Free energy of activation

8. What Affects Enzyme Activity?
Environmental Conditions
- increased temperature,
-salt concentration,
-pH

9. Toothpickase Activity
Directions: Time how long it takes you to break 10 toothpicks without looking. Then, ice your hands for a few minutes. Try breaking the 10 toothpicks again while timing yourself.
Temperature
Time to break 10 toothpicks (seconds)
Room temperature toothpickase
Cold toothpickase
How does temperature affect the time in which toothpicks are broken by toothpickase?

12. Acids, Bases and pH H2O  H+ + OH-
One water molecule in 550 million naturally dissociates into a Hydrogen Ion (H+) and a Hydroxide Ion (OH-)
Hydrogen Ion Hydroxide Ion
Acid Base
H2O  H+ + OH-

13. The pH Scale Indicates the concentration of H+ ions Ranges from 0 – 14
pH of 7 is neutral
pH 0 up to 7 is acid … H+
pH above 7 – 14 is basic … OH-
Each pH unit represents a factor of 10X change in concentration
pH 3 is 10 x 10 x 10 (1,000) stronger than a pH of 6

14. high OH- concentration
The pH Scale
low OH- concentration
high OH- concentration

15. Acids
Strong Acids have a pH of 0-3
Produce lots of H+ ions

16. Bases Strong Bases have a pH of 11 to 14
Contain lots of OH- ions and fewer H+ ions