enzymes. pre – key point 1: chemical reactions reactants products reactantsproducts

Enzymes

Pre – Key Point 1: Chemical Reactions

• Reactants Products

REACTANTS PRODUCTS

Key Point #1Enzymes are made of proteins and function

as catalysts, which speed up chemical reactions

Key Point #2

The energy needed to start a chemical reaction is called activation energy

Key Point #3Catalysts are enzymes that speed up

chemical reactions by lowering activation energy

For example…

Key Point #4Enzymes only catalyze specific reactions

due to the shape of the enzymes and the shape of the substrate (reactant) molecules

Active site:

Substrate:

Conformational shift to fit better

Key Point #5Enzymes have an optimum temperature and

pH at which they work best

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

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

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?