1. Enzyme s Chapter 2.5

2. Enzymes are catalysts for chemical reactions in living things

3. Why Are Enzymes So Important? Why are we devoting one whole lecture topic to a protein molecule? Nearly all chemical reactions in biological cells need enzymes to make the reaction occur fast enough to support life. Image: Jumping rope, Meagan E. KleinJumping rope From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

4. Enzymes allow chemical reactions to occur under tightly controlled conditions. Enzymes are catalysts in living things. Enzymes are needed for almost all processes. Most enzymes are proteins

6. What do enzymes do? Enzymes act as _________ in cellular reactions. Q: What does a catalyst do? Images: Activation energy graph, WikiActivation energy graph From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

7. …are REUSABLE. They are not consumed (used up) in the reactions they catalyze. Enzymes… From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

8. How do enzymes work? Enzymes catalyze reactions by weakening chemical bonds, which ________ activation energy. Image: Activation energy graph, WikiActivation energy graph From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

9. Meet the Enzyme : ___ _______ Important metabolic enzyme that harnesses energy for biological cells to use. Involved in synthesis of adenosine triphosphate (ATP), from:ATP - adenosine diphosphate (ADP) - a phosphate group and - energy from H+ ion gradient ATP is the most commonly used "energy currency" of cells. Reaction: ( ATP synthase) ADP + Pi -------  ATP substratesubstrate product Images: ATP synthase diagram, Tim VickersATP synthase diagram From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

10. How do you stop an enzyme? Irreversible egg protein denaturation caused by high temperature (while cooking it). __denature it! Alteration of a protein shape through some form of external stressprotein Example, by applying heat or changing pH.pH Denatured protein can’t carry out its cellular function. From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

11. Factors That Influence Enzyme Activity Temperature pH Cofactors & Coenzymes Inhibitors Image: Animation of Enzyme, WikiAnimation of Enzyme From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

12. What enzymes do I have around the house? detergents textiles (fabric) wine beer vinegar cheeses corn and wheat syrups leather biodegradable plastic starch into sugar yeast

13. Where are they found? Enzymes are found in many cleaning and spot removal and odor removal products. Enzymes are found in all living foods such as fruits and vegetables as they keep ripening. Enzymes are found in those agents that cause food spoilage, Enzymes are found in many food reactions such as yogurt, cheeses, saurkraut, pickles, fermentations of beer and wine, etc, Meat tenderizer is an enzyme milk products for lactose intolerant individuals is treated with lactase, an enzyme

14. Digestive enzymes are enzymes that break down food into usable material. The major different types of digestive enzymes are: amylase – breaks down carbohydrates, starches, and sugars which are prevalent in potatoes, fruits, vegetables, and many snack foods lactase – breaks down lactose (milk sugars) diastase – digests vegetable starch sucrase – digests complex sugars and starches maltase – digests disaccharides to monosaccharides (malt sugars) invertase – breaks down sucrose (table sugar) glucoamylase – breaks down starch to glucose alpha-glactosidase – facilitates digestion of beans, legumes, seeds, roots, soy products, and underground stems protease – breaks down proteins found in meats, nuts, eggs, and cheese pepsin – breaks down proteins into peptides

15. Enzymes… Have names that usually end in -_____.-Sucrase-Lactase-Maltase Image: Animation of Enzyme, WikiAnimation of Enzyme From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

16. Go to: http://redirectyourcarbs.com/carb- redirect-method/?sid=a1

17. Factors Affecting Enzyme Activity Temperature - Enzymes are proteins that function optimally at certain temperatures. They are inactivated or denatured by temperatures above 50 °C to 60 °C. Enzymes are not inactivated by freezing, but either work slowly or do not work at all. pH - Enzymes are sensitive to changes in acidity. For example, the high acidity of stomach juice is needed for the enzyme pepsin to function, whereas an enzyme called trypsin in the small intestine requires alkaline surroundings. Concentration of Enzyme - If pH and temperature are kept constant, the rate of reaction is proportional to the amount of enzyme present. The more enzyme there is, the more reactions that occur. Co-Enzymes - Some vitamins and minerals (e.g. copper, zinc, iron) in small quantities work with enzymes to speed up reactions. Enzyme Inhibitors - A pesticide called DDT stops the action of enzymes in insects, thereby killing them.

18. How acidic is your body? http://scienceforkids.kidipede.com/biology/cells/enzyme.htm

19. A catalyst lowers activation energy. Catalysts are substances that speed up chemical reactions. decrease activation energy increase reaction rate

20. Disruptions in homeostasis can prevent enzymes from functioning. –Enzymes function best in a small range of conditions. –Changes in temperature and pH can break hydrogen bonds. –An enzyme’s function depends on its structure.

21. are specific for what they will catalyze. fit with substrate like a lock and key____. Enzymes… From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

22. An enzyme’s structure allows only certain reactants to bind to the enzyme. –substrates –active site substrates (reactants) enzyme Substrates bind to an enzyme at certain places called active sites.

23. The lock-and-key model helps illustrate how enzymes function. –substrates brought together –bonds in substrates weakened Substrates bind to an enzyme at certain places called active sites. The enzyme brings substrates together and weakens their bonds. The catalyzed reaction forms a product that is released from the enzyme.

24. When an enzyme is interacting with it’s substrate, during the chemical reaction, together they are referred to as the … Image: Enzyme –substrate complex, UC DavisEnzyme –substrate complex From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

25. The more cans (substrate), the more $ (product). The more recycling machines (enzymes), the faster the cans turn into $. Enzymes are like tiny machines within living things. From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com $ $ $ $ $ $ $

26. Cofactors & Coenzymes substances (zinc, iron, copper, vitamins) Non-protein substances (zinc, iron, copper, vitamins) are sometimes need for proper enzymatic activity. Coenzyme vs Cofactor: What’s the difference? _________ more general term. Includes inorganic and organic molecules.organic molecules _________ type of cofactor, But specifically organic molecules. Image: Enzyme with Cofactor, Wiki. Ribbon-diagram showing carbonic anhydrase II. The grey sphere is the zinc cofactor in the active site.Enzyme with Cofactor From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

27. Meet the Enzyme : Catecholase Catecholase is present in most _Fruits_____ and __Vegetables________. It is the enzyme that facilitates the ________ of cut or bruised fruits and vegetables by catalyzing the following reaction: (______________) _________ + _____ -----------------  _____________ colorless substrate brown product Image: Bananas T. Port From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

28. Meet the Enzyme : Catecholase Lemon juice and other acids are used to preserve color in fruit, particularly apples, by lowering the ____ and removing the copper (cofactor) necessary for the enzyme to function. Reaction: catecholase catechol + O 2 ----------  polyphenol colorless substrate brown product Images: Apples, T. Port; Lemons, André Karwath; Enzyme with Cofactor, Wiki; pH scale, Edward Stevens, WikiLemonsEnzyme with CofactorpH scale From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

29. Meet the Enzyme : Bromelain Pineapple contains enzyme bromelain, which can digest protein Jell-O ® is made of gelatin, a processed version of a structural protein called _________ found in many animals, including humans. Collagen = big, fibrous molecule makes skin, bones, and tendons both strong and elastic. Gelatin you eat in Jell-O ® comes from the collagen in cow or pig bones, hooves, and connective tissues. (Yummie!) Examine 2 containers: a. In one, canned pineapple was used to make Jell-O ®. b. The other, fresh pineapple was used. Q: Why is one Jell-O solid and the other liquid? Image: Pineapple, Whaldener EndoPineapple From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

30. Meet the Enzyme : Bromelain (bromelain) collagen protein + H 2 0 --------------  amino acids substrate products Bromelain is a ______ enzyme that facilitates hydrolysis of protein. enzyme Remember, hydrolysis cuts molecule by adding water…the reverse of the hydration synthesis pictured to the left. FYI: Bromelain is used as a meat tenderizer. Breaks down the collagen in meat. So what do you think could happen to your tongue when you eat fresh pineapple? From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

31. Assignment At the end of most lectures, I will give you some type of in- class assignment or homework to evaluate your understanding of today’s topic. This assignment will always be open-book. Today you may be completing an experiment on the topic of Enzymes. See the ScienceProfOnline Virtual Cell Biology Classroom: Enzymes Lecture for a printable Word.doc of this assignment.ScienceProfOnline Image: Accumulation of polyphenol in apple, T. Port From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com