2. Enzymes …are proteins produced by living cells that act as biological catalysts - agents that speed up metabolic reactions by lowering energy barrier, but are themselves unchanged by the reaction.

3. What is an enzyme? 1. Enzymes are from what macromolecule? 2. What’s the basis of their chemical structure? 3. What process in your body might require enzymes? Give some examples 4. Are enzymes specific or general in their action? 5. Describe the “Lock & Key” analogy - both structurally & functionally as it relates to enzymes and substrates 6. Write an anabolic reaction using an enzyme. 7. Write an Catabolic reaction using an enzyme. 8. Explain the visual below. 9. How do enzymes work? And what do they do?

4. What is an enzyme? 1. Enzymes are from what macromolecule? 2. What’s the basis of their chemical structure? 3. What process in your body might require enzymes? Give some examples 4. Are enzymes specific or general in their action? 5. Describe the “Lock & Key” analogy - both structurally & functionally as it relates to enzymes and substrates 6. Write an anabolic reaction using an enzyme. 7. Write an Catabolic reaction using an enzyme. 8. Explain the visual below. 9. How do enzymes work? And what do they do? Protein Amine (H 2 N) Carboxyl group (-COOH) A specific substrate binds to the specific active site on the enzyme causing a reaction that… Lowers the activitation energy and Speeds up reactions to synthesize or break apart molecules Digestion - amylase, lipase, protease, peptidase, nucleas, lactase, sucrase,… specific The enzyme acts like the lock because the active site on it is very specific - only a certain substrate or key will fit it. A + B ---enzyme---> AB (also endergonic) AB ---enzyme---> A + B (also exergonic) This is a catabolic reaction where the bound substrate (AB) inserts inself (like a key) into the active site of the enzyme (like a lock), where by separating the molecule into A + B. Now the enzyme is free to react with another substrate Enzyme Active Site Substrate Enzyme-Substrate Complex

5. Structure and Function Enzymes act like a lock and key They have very specific active sites that bind to very specific sites on the substrate Lock & Key Model: Enzymes are referred to as “substrate specific” This is critical because it regulates what molecule it will speed up…unlike heating something, or mixing something - that changes everything it comes into contact with. Induced-Fit Model: Active site changes shape slightly to accommodate the substrate If the overall enzyme structure is changed (denatured) then it will probably not function the same. “Form dictates function.” ABAB

6. Check for Understanding Enzymes are what kind of macromolecule? What do enzymes act like? (What is the model called?) Which part is the enzyme? Which part is the substrate? What part of the enzyme forms a bond to the substrate? What is this model referred to as? What is it called when only a specific enzyme bonds to a specific substrate? What is the advantage of the Lock & Key Model? What is it called (what model) when the Active Site changes shape slightly to accommodate the substrate? What are two things enzymes do to reactions? What happens if the overall structure of enzymes are denatured (changed)? Label the parts below: Enzyme Active Site Substrate Enzyme-Substrate Complex Products

7. Catalyzed vs Uncatalyzed Reactions Energy Reaction Reactants 2H 2 O 2 Products 2H 2 O + O 2 Uncatalyzed Rxn Catalyzed Rxn Energy saved Activation Energy for catalyzed rxn Energy lost Exergonic Activation Energy for uncatalyzedrxn Draw & Label the following Graph 1. Title 2. X axis - Reaction 3. Y axis - Energy 4. Line A 5. Line B 6. XY 7. X + Y 8. A 9. B 10. C 11. D 12. E 13. F Word Bank: Activation Energy for catalyzed reactionEnergy lost (exergonic) Activation Energy for uncatalyzed reactionProducts (2H 2 O + O 2 ) Catalyzed reaction Reactants (2H 2 O 2 ) Catalyzed vs UnCatalyzed Reactions Uncatalyzed reaction

8. Activation Energy Free energy of Activation E A is the energy absorbed by reactants enabling them to break bonds, allowing a rxn to proceed. E A is critical to life because it regulates rxn’s, preventing spontaneous decomposition. G = the quantity of free energy. ∆G = G final state - G starting state Exergonic - releases energy ∆G < 0 Endergonic - requires energy ∆G > 0

9. KMnO 4 reacts with H 2 O 2 and turns colorless 21 molecules of H 2 O 2 2 molecules of H 2 O And 1 molecule of O 2 Will the beaker to the left require a lot of KMnO 4 drops or a little before seeing a persistent pink/brown? Why? Substrate H 2 O 2 Enzyme: Catalase Enzyme Substrate Complex H2O2H2O2 Enzyme: Catalase H2OH2O O2O2 What does this beaker show? How much KMnO 4 is needed before the persistent color? More or less drops than the 1 st beaker? What does this beaker show? How many drops of KMnO 4 is needed before the persistent color? Products What does this beaker show?

10. Relate & Apply Beano - made from a safe food-grade mold with Alpha-D-Galactosidase An enzyme that acts on foods with high alpha-linked sugars For example: cabbage, beans, cauliflower, brocoli,… Prevents gas - flatulence and/or bloat by converting raffinose, stachyose, and verbascose into their digestible sugar components: glucose, galactose, sucrose, and fructose. Detergent Enzymes act to break bonds holding stains on fabric Inhibitors How do you keep guacamole longer? How do you prevent apples from browning? Digestive Tract

11. What is catalase? Catalase is an enzyme produced in all animal cells and is used by those cells to rapidly break down (decompose) hydrogen peroxide into less reactive gaseous oxygen and water molecules. Hydrogen peroxide is a harmful by-product of many normal metabolic processes. To prevent damage, it must be quickly converted into other substances (O 2 and H 2 O). Catalase works at an optimum temperature of 37 ˚C, which is approximately the temperature of the human body (98.6˚F). Why do we refrigerate the lab catalase then? All known animals use catalase in every organ, with particularly high concentrations occurring in the liver. Catalase in industry: Food industry for removing hydrogen peroxide from milk prior to cheese production. Another use is in food wrappers, where it prevents food from oxidizing (apples at Subway). Textile industry, removing hydrogen peroxide from fabrics to make sure the material is peroxide-free. A minor use is in contact lens hygiene - a few lens-cleaning products disinfect the lens using a hydrogen peroxide solution; then a catalase is used to decompose the hydrogen peroxide before the lens is used again. Aesthetics industry (dermatology) - several mask treatments combine the enzyme with hydrogen peroxide on the face with the intent of increasing cellular oxygenation in the upper layers of the epidermis.

12. Where else do we have enzymes? Digestive Enzymes: Salivary enzymes (under tongue, back end of tongue, inner ridge of mandible) Salivary amylase (break down starches to simple sugars) Lingual lipase (preliminary break down of lipids) - can continue to function to a pH of 2 - 4 in the stomach Gastric Enzymes (stomach - 2 to 3 liters of gastric acid a day - HCl, KCl, NaCl) Peptidase (pepsin) - main digestive enzyme of the stomach - proteins Gastric amylase - continues some carbohydrate digestion Gastric lipase - butter fat digestion Pancreatic enzymes (triggered when protein and fats are present in the duodenum) Alkaline - helps to reduce the stomach acid as the food moves into the small intestine Peptidase - proteins Nucleases - nucleic acids (DNAase, RNAase) Pancreatic amylase - any remaining carbohydrates (starch, cellulose, glycogen) Bile (from the liver) - fat digestion Small Intestines enzymes Sucrase - breaks down sucrose into glucose and fructose Maltase - breaks down maltose into glucose Isomaltase - breaks down maltose and isomaltose Lactase - breaks down lactose into glucose and galactose Intestinal lipase - breaks down fatty acids Exopeptidases - breaks the peptide bonds of proteins

13. Digestive System and related Enzymes Salivary Enzymes Stomach Enzymes Pancreatic Enzymes Liver Enzyme Small Intestines Enzymes (duodenum) Salivary amylase Lingual lipase Pepsin Gastric amylase Gastric lipase Pepsidase Pancreatic amylase Nucleases Bile Sucrase Maltase Iosmaltase Exopepsidase Intestinal lipase

14. Looking at the red, uncatalyzed pathway, is this an exothermic or endothermic rxn? Looking at the blue, catalyzed pathway, is this an exothermic or endothermic rxn? How do you know? What are you looking at to determine that? Catalyzed vs Uncatalyzed Reactions Read over this graph

15. What effects a catalyst? Inhibitors can denature enzymes or block enzyme activity: ~ Temperature (in Biology - what’s optimal?) ~ pH (in Biology - what’s optimal?) ~ Time ~ Chemical Inhibitors (poisons & drugs)