1. Enzymes

2. What Are Enzymes? Most enzymes are Proteins
Act as a biological Catalyst to speeds up 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. Real Life Enzyme Example
Pepsin is an enzyme in the stomach
Protein is the substrate
Amino acids are the products

5. How do Enzymes Work?
Enzymes work by weakening bonds which lowers activation energy- the energy to get a reaction going

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

7. Enzyme-Substrate Complex
The substance (reactant) that an enzyme acts on is the substrate
Forms an enzyme –substrate complex
Enzyme
Joins
Substrate

8. Active Site
Active site is the restricted region of an enzyme molecule which binds to the substrate.
Active Site
Enzyme
Substrate

9. Induced Fit
Induced fit is a change in the shape of an enzyme’s active site
Induced by the substrate
Enzymes and substrate fit together like a “handshake”. Each slightly changing to make the fit better once they come into contact with each other

10. Induced Fit
Inducted fit is 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

11. Summary of How Enzymes Work
The substrate and the enzyme bond together.
A reaction occurs that changes the substrate into something new ( a product).
The enzyme is NOT changed and recycles to react again with a new substrate molecule.

12. Enzymes are sensitive to their environment
DENATURING ENZYMES – when enzymes lose their structure so they don’t work
prNotice the process is often reversible when favorable conditions are re-established.

13. What Affects Enzyme Activity?
1.Extreme Temperature (hot & cold) are the most dangerous
- extreme temps may denature (unfold) the enzyme. Example: high fever
2. pH level (most enzymes like pH near neutral)

15. Summary:
Enzymes are proteins that act as catalysts.
Catalysts are molecules that speed up reactions without being changed or used up.
Enzymes have an active site where the substrate binds to form the product.
Enzymes can be denatured by changes in the environment.
Enzymes work by lowering the activation energy of the reaction.