1. Chemical Reactions and Energy

2. What is Energy? Energy is the ability to move or change matter
Kinds of Energy
Light
Heat
Chemical
Mechanical
Electrical

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

4. How do enzymes Work?
Enzymes work by weakening bonds which lowers activation energy

5. Induced Fit
A change in the configuration of an enzyme’s active site (H+ and ionic bonds are involved).
Induced by the substrate.
Enzyme
Active Site
substrate
induced fit

6. Energy in Chemical Reactions

8. Activation Energy

9. Figure 6.13 Enzymes lower the barrier of activation energy

10. What Affects Enzyme Activity?
Three factors:
1. Environmental Conditions
2. Cofactors and Coenzymes
3. Enzyme Inhibitors

11. 1. Environmental Conditions
1. Extreme Temperature are the most dangerous
- high temps may denature (unfold) the enzyme.
2. pH (most like pH near neutral)
3. Ionic concentration (salt ions)

12. Factors affecting Enzyme Activity
Temperature

13. pH
Just as each enzyme has an optimal temperature, it also has a pH at which it is most active.
The optimal pH values for most enzymes fall in the range of pH 6-8, but there are exceptions.