ENZYMES

1. NEED A JOB DONE? Call the trusted professionals at ENZYME, Inc. 845-CAT-ALYST ENZYMES Need a shed built? xSHED Need a garage demolished? xRUBBLE Need a toilet replaced? xPOTTY How about fix a leaky roof? xLEAK

2. Need a job done? • How do things “change” in your body? • How are proteins built? • How are starches digested? • What causes these Chemical Reactions? • Enzymes! • Enzymes are catalysts.

3. Enzymes • Enzymes are protein catalysts • Enzymes help all chemical reactions occur • A catalyst gets things going! • (Think GLOBAL! What was the catalyst for WWI?) • Enzymes control the rate of all chemical reactions!

4. Lock and Key • When you go home at night and the door is locked, can it open itself? • Nope. • Can you use your mom’s car key to open it? • No. • You need a key that is just the right shape to fit in that lock. Otherwise, you're stuck in the cold. • And you had best start building that igloo!!!

5. Specificity • Enzymes work in a similar way (locks and keys). • Enzymes complete very specific jobs and do nothing else. • They are very specific “locks” and the compounds they work with are the special keys (they are called “substrates”). • Substrates are the raw materials needed to make a product

6. Different Enzymes • In the same way that there are door keys, car keys, and bike-lock keys, for every different door, car and bike lock… • There are enzymes for every different reaction that has to occur in living things.

7. So? • The TYPE of chemical reactions that occur in cells depends on the TYPE of enzymes present in the cell! • Enzymes are SPECIFIC to the reaction • And, Enzymes can be used over and over and over and … you get the idea! Back to ENZYME, Inc…….

8. Call 888-CAT-ALYST • When you need a job done, you call ENZYME, Inc. • The “operator” decides which contractor to send to complete the job

9. Contractor • The contractor visits the site and finds the raw materials • He begins working on the job assigned (he’s part of the “job” so he’s now the “enzyme substrate complex”) • The raw materials are now a final product • When he’s done… he walks away in search of another job.

10. Here’s the deal…. There are four steps in the process: An enzyme and a substrate are in the same area • Nothing can happen if they never meet each other! Hi, I’m your friend, Enzyme. Nice to meet you, I’m Substrate.

11. The enzyme bonds with the substrate at a special area called the active site. • The active site is a specially shaped area of the enzyme that fits around the substrate. • The active site is the keyhole of the lock.

12. Enzyme-Substrate Complex A “complex” made up of a substrate bound to the activesite of an enzyme The enzyme and substrate temporarily BIND together • LETTER C

13. The enzyme lets go because it’s job is done! • Enzymes are never changed in the reaction. • Only the substrate (raw material) changes. • The substrate is now a product. Which is the Enzyme-Substrate Complex? A, B, or C B A C

14. Can you stop them? ACK! It’s the Evil Enzyme Monster! • What if enzymes just kept going and converted every molecule in the world? • What if they never stopped... like some evil monster??? • Enzyme activity is regulated (and even stopped) by: • Temperature • pH levels

15. Activation Energy • Enzymes function by lowering the activation energy of reactions. Range B is the “activation energy” required to get the reaction “over the hump”…

16. The Rate of Chemical Reactions • The rate (how fast or slow) of chemical reactions is directly controlled by the enzymes present. • And, if enzymes are affected by certain factors, then…the chemical reaction rate is affected as well!

17. Enzyme Activity and Temp/pH • The activity of enzymes is affected by changes in pH and temperature. • Each enzyme works best at a certain pH (left graph) and temperature (right graph), its activity decreases above and below that “optimum” point. What does optimum mean?

18. Why does this happen? • Remember! Enzymes are PROTEINS • Proteins are DENATURED by pH and Temperature extremes • Denaturing means “de”stroying the “natur”al shape (the way the protein is folded) • If the protein unfolds, it loses it shape • If it loses its shape, it loses its ability to function! • Structure and Function go hand in hand!

19. Enzyme Names • Enzymes are named after the substrate they can act upon • Plus, most of them end in “ase”! • For example: • Protease breaks down protein • Lipase breaks down lipids (fat) • Amylase break down starches and other carbohydrates • Amyl is Greek for starch! • What do you think Cellulase breaks down? • Hint: humans lack this enzyme! _______________

20. This is how it works… The enzyme can be reused! The enzyme is a biological catalyst!

21. An Example Substrates Sucrose + H2O Glucose + Fructose What do you think the name of this enzyme is??? Hint: It works on “Sucrose”!!! Products

22. Enzymes and Homeostasis • Homeostasis is the maintenance of a constant internal balance • A “steady state” • In living things, homeostasis depends on enzyme function. • Enzymes can break up harmful substances that might disrupt homeostasis. • And homeostasis maintains conditions necessary for enzymes to function.

23. Summary • Enzymes are proteins (made of amino acids) and can be denatured by temperature and pH. • They are polypeptide chains! • Enzymes are catalysts, substances that change the rate of a chemical reaction. • Enzymes are unchanged by the reaction (which is why they can be reused over and over again)! • Enzymes are named after their substrates. • The name for an enzyme generally ends in “ase”.