ENZYMES VACHS BIOLOGY

DO NOW What type of reactions involve the breaking of chemical bonds? Which type of reactions involve the making of chemical bonds? What is activation energy? What are the differences between physical reactions and chemical reactions? What factors can change the activation energy of a reaction?

1. What is HAPPENING HERE?

2. ENZYMES: NATURE’S CATALYSTS

What is a CATALYST? 3. Catalyst: a substance that speeds up the rate of a chemical reaction. 4. Catalysts lower a reaction’s activation energy.

ENZYMES AN ENZYME IS CALLED “NATURE’S CATALYST.” … SO WHAT DO WE THINK ENZYMES DO?

ENZYMES 5. Enzyme: proteins that speed up chemical reactions that take place in cells. - THEY LOWER THE ACTIVATION ENERGY OF A REACTION!!!

6. ENZYME: LACTASE FUNCTION: Speeds up the breakdown of milk. Connections: What does it mean to be “lactose intolerant”?

ENZYME: LACTASE Without lactase, you can’t digest milk! Without lactase, it would take 78 MILLION YEARS TO DIGEST MILK!!!!!!!!

7. ENZYME: ALCOHOL DEHYDROGENASE Predictions: What do you think this enzyme might do?

ENZYME: ALCOHOL DEHYDROGENASE FUNCTION: Alcohol dehydrogenase helps break down alcohol. People who do not produce alcohol dehydrogenase experience “Alcohol Flush,” also known as an “Asian Flush.”

8. ENZYMES … OR enzymes help put things together FASTER Enzymes either help break things down FASTER OR enzymes help put things together FASTER

ENZYMES LACTOSE -------> GLUCOSE + GALACTOSE COLD CALLS: 9. ENZYMES DON’T GET USED UP IN CHEMICAL REACTIONS! THEY ARE NOT PRODUCTS OR REACTANTS!!! LACTASE LACTOSE -------> GLUCOSE + GALACTOSE COLD CALLS: 11. What is/are the reactant(s) in this reaction? 12. What is/are the product(s) in this reaction? 13. What enzyme is CATALYZING this reaction?

How do ENZYMES WORK? 14. Each enzyme only works for ONE specific reaction - This is often called the lock and key model (Why?)

How do ENZYMES WORK? 15. Enzymes work by lowering the activation energy (energy required for a chemical reaction to happen).

ENZYMES VIDEO http://www.youtube.com/watch?v=MjdIqDoDIYA&feature=relmfu

What is a Substrate? 16. A substrate is the reactant (starting molecule) of an enzyme-catalyzed reaction. 17. It fits into the active site of an enzyme.

LOCK AND KEY? Which one is the lock? Which one is the key?

ENZYMES ANIMATION http://www.lpscience.fatcow.com/jwanamaker/animations/Enzyme%20activity.html

18. Summary Movement/Voices: “Restaurant,” sitting still Instructions: Write a summary of the enzyme process, including the following vocabulary: catalyst, enzyme, substrate, active site, “lock and key,” chemical reaction, reactants, and products. Success: Write in complete sentences, use all the vocabulary, and finish in 5 minutes!

Temperature Our bodies work best at a certain temperature… How do you feel when you have a fever?? How do you feel when you’re really cold?

Enzymes Our bodies (and the enzymes we need) work best at a certain temperature and pH! 19. Factors that affect enzymes: Temperature pH Substrate concentration (amount of available substrate)

Denature Looking at the prefix “de” and the word “nature,” what predictions do we have for what this word means? Think of “de-humidifying….”

Denature 20. When an enzyme is placed in extreme pH or temperature, it “denatures,” meaning it changes to shape. 21. When it changes shape, what happens to the lock and key fit? Will the enzyme be able to function?

Toothpickase Activity Voices/Movement: “Restaurant,” pick one partner to collect your materials! Instructions: Watch and listen as I describe the instructions on the board. They are also written on your lab sheets! Success: Listen and read so you understand the instructions! Then work with your partner to finish your lab activity and answer all your questions in the time allowed!