Enzymes: The Biological Catalysts of Life

1. Enzymes The protein catalyst of life

2. Enzyme Vocabulary • Enzymes end in –ase • Maltase binds to maltose • Lactase binds to lactose • Lipase breaks down fat • Amylase is found in saliva • Catalyst: • Substance that affects the rate of a chemical reaction WITHOUT BEING ALTERED • Because it is not altered, can do same thing over, and, over, and, over, and over……. • Enzymes are ORGANIC OR BIOLOGICAL CATALYSTS

3. Enzymes are little Energizer Bunnies!

4. Enzyme Vocabulary con’t…. • Substrate: • The substance upon which the enzyme reacts • Active site: • Site where enzyme binds to substrate • Denature: • When enzyme’s shape is altered due to: • high temp • Wrong (pH) acids or bases

5. You Tube clip: How enzymes work • http://www.youtube.com/watch?v=Pvgpk75us18&feature=related

6. Importance of Enzyme Shape • Enzymes have specific shapes • This means enzymes are specific to their substrate • They will only attach to substrate that “fits” their shape • If shape of enzyme is denatured, will it be able to bind to its substrate? • NO! • Two things can cause denaturing: • Temperature • pH

7. Enzyme-Substrate Complex • Formed when enzyme binds to substrate • Very specific • Lock and Key Model: • Enzyme-substrate complex often compared to a lock and key • Active site on enzyme can only “FIT” or bind to a specific substrate • Example: Amylase will bind to starch, but not cellulose which is also made of just glucose DEMO

8. Enzyme-substrate Complex

9. The Enzyme Jingle!SUNG TO “JINGLE BELLS”! Shape, Shape, Shape Shape, Shape, Shape Enzymes have a shape If active site is denatured It won’t bind su-ubstra-ate Shape, shape, shape Shape, shape, shape Enzymes have a shape Wrong pH or temperature Will affect its shape

10. What affects Enzyme Reaction Rates? • Remember, enzymes speed up reactions • What can affect the rate at which enzymes perform? • It’s shape! • Denaturing affects rate • The amount of enzyme and substrate!

11. Enzyme shape and reaction rate: Temperature • Enzymes have a specific temperature range at which they work best • EX. Human enzymes work best at 37°C • Temps not in the optimal range will cause enzymes to denature • Shape is altered, so reaction rates are SLOWED or stopped altogether • Reaction rates will DROP dramatically depending on how much denaturing of enzyme DEMO

12. Temperature vs. Reaction Rate

13. Enzyme shape and reaction rate: pH • Enzymes have a specific pH range at which they work best • EX. Most enzymes work best at pH 7 • Where in the body would enzymes be optimal at a low (acidic) pH? Why? • In stomach. This is because stomach acid has a low pH • pH not in the optimal range will cause enzymes to denature • Shape is altered, so reaction rates are SLOWED or stopped altogether • Reaction rates will DROP dramatically depending on how much denaturing of enzyme

14. pH vs. Reaction Rate

15. Enzyme amount and reaction rate • Enzyme rate also depends on the amount enzyme and substrate • Little enzyme, lots o’ substrate: • Slower rates • How can we speed up the rate? • Add more enzyme until max. rate achieved.

16. Substrate Concentration vs. Reaction Rate

17. CAPTAIN ENZYME! He is a biological superhero, roaming our bodies for health and justice. • Create a quote that captain enzyme would say using the vocab we have learned this week. • Make sure you are using the terms properly! • Grade will be based on: • Use of vocab • Creativity • Superhero Impersonation