1. Enzymes: Special Proteins
SWBAT
Determine the functions of enzymes
Determine enzyme regulation
Determine the effect of temperature, pH, and enzyme/substrate concentration on enzyme activity

2. Properties of Enzymes Properties They are proteins Highly specific
Have active site
Reused/ remains unchanged
LOWERS ACTIVATION ENERGY!!!
Energy required to start a chemical reaction

3. How Enzymes Work Substrate – Attaches to the active site of an enzyme
Active Site – the pocket or groove, that the substrate fits into
Like a lock and key: enzyme/substrate combination allows reaction to occur like the correct key in a lock opens a door

4. Enzyme Action: Steps
Enzyme attaches to its specific substrate and fits snugly within the active (binding) site.
Enzyme and substrate interact
Products are formed and released.

5. Enzymes in Depth
Enzymes are the biological substance (proteins) that act as catalysts and help complex reactions occur everywhere in life

6. Enzymes are recycled and reused many times for the same
type of reaction
(never used up)
Example:
Sucrase converts sucrose  glucose + fructose
Sucrase remains unchanged

7. Factors that affect enzymes
Factors that affect the strength of an enzyme: pH
Temperature
Concentration of enzymes
Concentration of Substrate

8. Temperature Temperature
Each enzyme has an optimum temperature in which it works the best

9. Also a range of temperature in which it will work
When the temperature drops/cools, activity of enzyme decreases/slows down
When temperature increases
Rate of reaction increases
Then decreases
Then stops (Denature)
Most Biological Enzymes work in a temperature of 37°C

10. pH
Most of biological enzymes work in a pH of 7, but there are some exceptions (Pepsin and Trypsin)
Enzymes are affected by pH and have an optimum pH
If the pH goes above or beyond the range, the enzyme becomes denatured

11. Concentration of Substrate and Enzymes
The rate of reaction of the enzyme can be increased by increasing the concentration of the enzyme
After a while the rate of reaction becomes constant
At this point , the rate of the reaction can be increased only by increasing the concentration of the substrate

12. When Enzymes No Longer Work
Environmental factors can change an enzyme. This process is called denaturation.
Denatured enzymes no longer work.
Example of Enzymes in action