1. Enzymes

2. Pre – Key Point 1: Chemical Reactions Reactants  Products REACTANTSPRODUCTS

3. Key Point #1 Enzymes are made of proteins and function as catalysts, which speed up chemical reactions

4. Key Point #2 The energy needed to start a chemical reaction is called activation energy

5. Key Point #3 Catalysts are enzymes that speed up chemical reactions by lowering activation energy

6. For example…

7. Key Point #4 Enzymes only catalyze specific reactions due to the shape of the enzymes and the shape of the substrate (reactant) molecules Active site: Substrate:

8. Conformational shift to fit better

9. Key Point #5 Enzymes have an optimum temperature and pH at which they work best

10. Key Point #6 Denaturation = proteins lose their tertiary structure and can no longer function properly –Temperature too hot –pH too acidic or basic –UV light –Anything that breaks chemical bonds

11. Key Point #7 Enzymes have names that end in “-ase” –Examples: Amylase Lactase – breaks down lactose Sucrase – breaks down sucrose Pectinase – breaks down pectin Helicase – breaks down helixes

12. Exit Ticket 1.What is the purpose of catalysts? 2.How do catalysts do this? 3.What is a substrate? 4.What is the active site? 5.What does denaturation mean? 6.What are 2 ways enzymes can get denatured? 7.What is the optimum temperature and pH for an enzyme in the human body? 8.How do you know an enzyme is an enzyme based on its name?