Cell ENERGY & ENZYMES
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CELL ENERGY & ENZYMES CH. 5.10 - 5.16, CH. 6 & CH. 7 CELLS MUST CREATE AND/OR PROCESS ENERGY USING CHEMICAL REACTIONS. • ENZYMES: are catalyst proteins. • CATALYST: a substance that causes a chemical reaction to speed up. The substance is not changed or used up. WHAT ARE ENZYMES? • Most enzymes are proteins • Act as a catalyst to accelerate reactions • Not permanently changed in the process ENZYMES • Specific for what they catalyze • Are reusable • End in –ase “Lock and Key” HOW DO ENZYMES WORK? Enzymes work by weakening bonds, which lowers the activation energy. http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html ENZYMES Free Energy Free energy of activation Reactants Products Progress of the reaction THE ENZYME–SUBSTRATE COMPLEX The substance (reactant) that an enzyme acts on is the substrate. Substrate Joins Enzyme ACTIVE SITE A restricted region of an enzyme molecule which binds to the substrate. Active Site Substrate Enzyme WHAT AFFECTS ENZYME ACTIVITY? Three factors… 1.Environmental Conditions 2.Cofactors & Coenzymes 3.Enzyme Inhibitors ENVIRONMENTAL CONDITIONS • Extreme temperature are the most dangerous - high temps may denature (unfold) the enzyme • pH (most “like” 6 - 8 pH, near neutral) • Ionic concentration (salt ions) COFACTORS & COENZYMES Inorganic substances (i.e.: zinc, iron) and vitamins are sometimes need for proper enzymatic activity. Example: Iron must be present in the quaternary structure of hemoglobin in order for it to pick up oxygen. 2 TYPES OF ENZYME INHIBITORS 1. Competitive inhibitors: are chemicals that resemble an enzyme’s normal substrate and compete with it for the active site. Substrate Competitive inhibitor Enzyme 2 TYPES OF ENZYME INHIBITORS 2. Non-competitive inhibitors: Inhibitors that do not enter the active site, but bind to another part of the enzyme causing the enzyme to change its shape, which in turn alters the active site. Substrate Enzyme active site altered Noncompetitive Inhibitor ENZYMATCH.COM • Understanding the importance of finding your perfect lock or key! • Enzymatch.com guarantees to speed up your match making experience! PURPOSE OF ENZYMES: • 1. Build small molecules into larger molecules (ex. synthesis of DNA) • 2. Break down large molecules into smaller molecules (ex. digestion of foods) • 3. To reduce the amount of ENERGY needed to perform the chemical reaction. Enzymes A Fun Introduction: https://www.youtube.com/watch?v=X TUm-75-PL4&feature=related ANABOLIC VS. CATABOLIC ANABOLIC REACTIONS CATABOLIC REACTIONS • Use energy to build larger molecules from smaller molecules • Release energy by breaking down larger molecules into smaller molecules • Example: Photosynthesis • Example: Cellular Respiration MEMORY TRICK! •Anabolic reactions •Build molecules •Catabolic reactions •Destroy molecules EXAMPLES OF ENZYMES Enzyme Name Lipase Peptidase Lactase Cellulase Pectinase Polymerase Job EXAMPLES OF ENZYMES Enzyme Name Lipase Peptidase Lactase Cellulase Pectinase Polymerase Job Breaks down lipids (fats) EXAMPLES OF ENZYMES Enzyme Name Job Lipase Breaks down lipids (fats) Peptidase Breaks down peptide ponds that hold amino acids together (proteins) Lactase Cellulase Pectinase Polymerase EXAMPLES OF ENZYMES Enzyme Name Job Lipase Breaks down lipids (fats) Peptidase Breaks down peptide ponds that hold amino acids together (proteins) Lactase Breaks down lactose found in dairy products Cellulase Pectinase Polymerase EXAMPLES OF ENZYMES Enzyme Name Job Lipase Breaks down lipids (fats) Peptidase Breaks down peptide ponds that hold amino acids together (proteins) Lactase Breaks down lactose found in dairy products Cellulase Breaks down cellulose found in cell walls Pectinase Polymerase EXAMPLES OF ENZYMES Enzyme Name Job Lipase Breaks down lipids (fats) Peptidase Breaks down peptide ponds that hold amino acids together (proteins) Lactase Breaks down lactose found in dairy products Cellulase Breaks down cellulose found in cell walls Pectinase Breaks down pectin found in cell walls Polymerase EXAMPLES OF ENZYMES Enzyme Name Job Lipase Breaks down lipids (fats) Peptidase Breaks down peptide ponds that hold amino acids together (proteins) Lactase Breaks down lactose found in dairy products Cellulase Breaks down cellulose found in cell walls Pectinase Breaks down pectin found in cell walls Polymerase Builds DNA and RNA LACTOSE INTOLERANCE Lactose Lactase Enzyme Glucose + Galactose Monosaccharide Disaccharide www.unitedstreaming.com - “Lactose Intolerance” GHScardinal greenwich Monosaccharide Pectin and cellulose are two polysaccharides that cross link with proteins to create the cell membrane. Apple juice companies use Cellulase & Pectinase to break down the cell wall and release juice. APPLE JUICE LAB • In this lab you will be researching which environmental factors will improve or interfere with juice production. • You will investigate the effect temperature. You will expose the enzyme to three levels of temperature. • After the enzyme has been treated, you should determine which condition lead to the greatest juice production. • CATALASE is an enzyme found in living things. Its job is to break down the poison hydrogen peroxide. 2 H 2O 2 • • • • Substrate(s)? Enzyme? Reactant (s)? Product(s)? catalase Hydrogen Peroxide Catalase Hydrogen Peroxide Water and Oxygen 2 H2 O + O 2 PART I: WHICH FOOD ITEM HAS THE MOST CATALASE? 1. Place three small pieces of each item on a plate: chalk, hamburger, liver, spinach & carrot. 2. Pour enough hydrogen peroxide to cover each food type. 3. Note the speeds of the reactions. The faster the reaction, the more vigorously the liquid bubbles. 4. List the food items in order from fastest reacting to slowest reacting. PART I QUESTIONS 1. Which food item contains the most enzyme (catalase)? 2. Which, if any, of the items did not produce a reaction? If a substance produced no reaction, explain why. 3. What two products does hydrogen peroxide change into when it breaks down? 4. Would catalase act on other chemicals other than hydrogen peroxide? Why or why not? CAN CATALASE TAKE THE HEAT? 1. Place three small pieces of raw liver and three small pieces of boiled liver on a plate. 2. Pour enough hydrogen peroxide to cover the plate. 3. Compare the speeds of the reactions. Based on this test, what assumption can you make about the effect of boiling catalase? DENATURATION OF ENZYMES • Objectives - Students will be able to: 1. Identify two variables that denature enzymes. 1. Model denaturation of an enzyme and describe how it affects reaction rates. TEMPERATURE • If temperature is too low, molecules move too slow and may never combine. • As temperature increases, enzymes could unfold permanently • OPTIMAL TEMPERATURE: a specific temperature at which an enzyme’s catalytic activity is at its greatest DO ALL ORGANISMS HAVE THE SAME OPTIMUM TEMPERATURE FOR THEIR ENZYMES? An enzyme found in Wild Alaskan Salmon An enzyme found in Bacteria An enzyme found in Humans THE SAME GOES FOR pH • pH: Each enzyme works within a small pH range. When an enzyme is NOT in its optimal pH environment the active site of the enzyme changes shape. • Acidic pH levels: 0 - 6 • Neutral pH level: 7 • Basic pH levels: 8 - 14 • OPTIMAL pH: a specific pH level at which an enzyme’s catalytic activity is at its greatest. pH SCALE Acidic Neutral Basic DO ALL ENZYMES IN AN ORGANISM HAVE THE SAME OPTIMUM PH? Amylase 7.4 pH Pepsin Trypsin 1 -2 pH 8 pH WHAT HAPPENS WHEN AN ENZYME REACHES PAST IT’S OPTIMAL TEMPERATURE OR pH? DENATURATION (denature): The enzyme’s bonds and structure breaks down causing it to lose its shape. The active site is no longer functional. Denatured proteins will not go back to their original shape!! PENNY-ASE LAB • Model Denaturation of enzymes by completing the Penny-Ase Lab!!! LORENZO’S OIL • 1992 – Based on the true story of Augusto and Michaela Odone, two parents in a relentless search for a cure for their son’s rare and debilitating Adrenoleukodystrophy • Click here to watch the official Lorenzo’s Oil trailer • During the film, please answer the questions provided. REFLECTION • Please take some time to write a reflection: 1. How were you impacted by this film? 2. How would you handle this type of situation? 3. How did this film relate to our enzyme unit? CELL ENERGY Photosynthesis Cell Respiration CELL ENERGY Photosynthesis Cell Respiration OVERVIEW 6 CO2 + 6 H20 C6H12O6 + 6 O2 STRUCTURE OF A LEAF • Photosynthesis: A process that only autotrophs perform. The process converts sunlight energy into chemical energy (glucose). Energy stored in the glucose can be transferred to other organisms when the molecules are consumed as food. • Where does photosynthesis occur in plant cells? CHLOROPLAST ANATOMY OF A CHLOROPLAST IT’S A TWO PART PROCESS! • Process #1: Requires Light (Light Reactions) • Process #2: Does NOT require light (Dark Reactions) Misnomer: Dark reactions don’t require “dark.” They can take place independent of light. LIGHT REACTIONS chloroplasts individual cell Elodea leaf cells, 100 X HOW DOES THE CHLOROPLAST ABSORB SUNLIGHT ENERGY? • Pigments: Light absorbing molecules. Below are the most common pigments found in plants • Chlorophyll a (green) • Chlorophyll b (green) • Carotenoids (yellow, orange, red) Chlorophylls absorb most strongly in the violet-blue region of the visible spectrum and reflect light in the green region of the spectrum. This is why plant parts that contain chlorophyll appear green to the human eye. BECAUSE CHLOROPHYLL ABSORBS EVERYTHING BUT GREEN! GREEN is being reflected back to your eye. CHECK FOR UNDERSTANDING! •Answer the following questions based on Thomas Engelmann’s photosynthesis experiment! THOMAS ENGELMANN’S EXPERIMENT What is a valid conclusion based on this graph? 1. O2 production decreases as the wavelength increases from 550 – 650 nm 2. Respiration rate in bacteria is greatest at 550 nm 3. Photosynthetic rate in the algae is greatest in blue light 4. The algae absorb the greatest amount of O2 in red light THOMAS ENGELMANN’S EXPERIMENT What is a valid conclusion based on this graph? 1. O2 production decreases as the wavelength increases from 550 – 650 nm 2. Respiration rate in bacteria is greatest at 550 nm 3. Photosynthetic rate in the algae is greatest in blue light 4. The algae absorb the greatest amount of O2 in red light THOMAS ENGELMANN’S EXPERIMENT Photosynthetic rate in the algae is greatest in blue light Evidence: 1. 2. 3. Animation of experiment WHY DO LEAVES APPEAR GREEN? These wavelengths are REFLECTED back to our eyes!!! WHY DO LEAVES APPEAR GREEN? In the fall, when Chlorophyll is no longer produced, the accessory pigments now become the dominant pigments, and those colors are reflected back to us too! WHY ARE LEAVES NEVER BLUE? Because chlorophyll absorbs blue light best and never reflects it back to our eyes!!! Reactants (Into the Chloroplast) Word Formula Chemical Formula Water + Carbon Dioxide H2O + CO2 Sunlight Sunlight Products (Out of the Chloroplast) Glucose + Oxygen C6H12O6 + O2 OVERVIEW FIGURE 7.8A Light Photosystem II Stroma Electron transport chain Provides energy for synthesis of ATP by chemiosmosis NADP H Light Photosystem I 1 Primary acceptor Thylakoid membrane Primary acceptor 2 4 P700 P680 Thylakoid space 3 H2O 1 2 5 O2 2 H 6 NADPH BUT THERE ARE TWO PHOTOSYSTEMS! WHAT ARE THE TWO MAIN PRODUCTS OF THE LIGHT REACTIONS (BOTH PHOTOSYSTEMS)? 1.) 2.) These are both sent to the Calvin Cycle (dark reactions/light independent reactions). CALVIN CYCLE ANIMATION • http://highered.mcgrawhill.com/sites/0070960526/student_view0/chapter5/animatio n_quiz_1.html Do NOT worry about the specific molecule names. Pay close attention to how the light reactions interact with the dark reactions. What are the start and end points and “materials” used? MY MOVIE CLIP NOTES • Location? _____________________________________ • What enters the Calvin Cycle? __________________ • What is used from the light reactions? _____________________________________ • What is formed? ________________________ 3 G3P HOW ARE THE TWO PARTS LINKED? By ATP and NADPH PRODUCING GLUCOSE… To synthesize one glucose molecule, the Calvin Cycle uses 6 CO2 molecules, 18 ATP, and 12 NADPH. PHOTOSYNTHESIS OVERVIEW PHOTOSYNTHESIS OVERVIEW G3P PART 1: LIGHT REACTION PART 1: LIGHT REACTION PART 2: CALVIN CYCLE PART 2: CALVIN CYCLE G3P FLOATING LEAF DISK LAB • Objectives: Students will be able to 1) observe photosynthesis happening right before their eyes!!! and 2) determine which level of light intensity will help spinach leaves perform photosynthesis the best. • First, we need our spinach disks to sink. I will demo the process and then let you try your own! PHOTOSYNTHESIS DRAWINGS! Photosynthesis Overview – Page 118 Light Reaction in detail – Page 114 Calvin Cycle in detail – Page 116 Full sheet or Half sheet drawings – IN COLOR CELL ENERGY Photosynthesis Cell Respiration HOW DOES OUR BODY BREAK DOWN THIS BREAD? BREAKS DOWN INTO MICROSCOPIC MOLECULES Loaf of bread Bread crumbs GLUCOSE’S FINAL DESTINATION… CELLULAR RESPIRATION The process of the mitochondria breaking down glucose into useable energy. The energy is released in the form of ATP. GLUCOSE Cellular Respiration ENERGY (ATP) ADENOSINE TRIPHOSPHATE • ATP: (Adenosine triphosphate) a biological molecule that provides chemical energy for cellular activities • Cellular Activities that require ATP: • • • • Active Transport of the cell membrane Making new DNA and new cells Muscle contractions Nerve impulses Glucose ATP ATP FUNCTION ENERGY IS RELEASED WHEN: The bond between the 2nd and 3rd phosphate groups is broken, forming a molecule called ADP (adenosine diphosphate). CELLULAR RESPIRATION Reactants (Into Mitochondria) Word Formula Chemical Formula Products (Out of Mitochondria) Glucose + Oxygen Water + Carbon Dioxide + ATP C6H12O6 + O2 H2O + CO2 + ATP WHAT TYPE OF ORGANISMS PERFORM CELLULAR RESPIRATION? AUTOTROPHS • An organism that can capture sunlight energy and produce glucose (chemical energy). HETEROTROPHS • An organism that obtains chemical energy from the food it eats • AKA: producer • AKA: consumer, herbivore, carnivore, decomposer, omnivore • Examples: plants, algae & some bacteria • Examples: animals, fungi, & most bacteria CELLULAR RESPIRATION DRAWINGS! Cell Respiration Overview – Page 100 Glycolysis – Page 94 Citric Acid / Krebs Cycle – Page 96 ETC (Oxidative Phosphorylation)- Page 98 Fermentation – Page 101 Full sheet or Half sheet drawings – IN COLOR CELL RESPIRATION OVERVIEW CELL RESPIRATION OVERVIEW PART 1: GLYCOLYSIS http://www.mcgrawhill.ca/school/applets/abbio/quiz/ch05/how_glycolysis_works.swf GLYCOLYSIS SUMMARY TRANSITION TO KREBS / CITRIC ACID CYCLE PART 2: KREBS / CITRIC ACID CYCLE http://www.mcgrawhill.ca/school/applets/abbio/quiz/ch05/how_the_krebs_cycle_wor.swf PART 3: OXIDATIVE PHOSPHORYLATION http://www.mcgrawhill.ca/school/applets/abbio/ch05/electrontrans_electron.swf WITHOUT O2: FERMENTATION CELL RESPIRATION REACTIONS CELL RESPIRATION REACTIONS YEAST & CELLULAR RESPIRATION LAB • Objective: • To perform a lab that assesses which food product is most efficient for yeast cellular respiration. YEAST - MAJOR CHARACTERISTICS • • • • Unicellular Fungi Eukaryotic Anaerobic Capable of forming colonies on solid culture media (see pictures on the right). • Occur worldwide • Over 1,500 species Significance of Yeast Food Industry Fermentation of bread, beer, and wine. E.g. Saccharomyces cerevisiae (also called baker’s yeast) used in baking and fermenting of alcoholic beverages. Medical E.g. Candida albicans - common in the human mouth, but can become pathogenic and cause Candidiasis (infection). Biofuel Industry Production of ethanol for car fuel. WHICH FOOD PRODUCT IS MOST EFFICIENT FOR YEAST CELLULAR RESPIRATION?. Carbon Dioxide Types of food: Table sugar Flour Vegetable Oil Yeast, Water and Food WHICH FOOD DO YOU PREDICT WILL WORK BEST? Table Sugar Flour Oil ILLUSTRATE INTERDEPENDENCE • Illustrate the interdependent relationship that occurs between photosynthesis and cellular respiration. INTERDEPENDENCE POSTERS • On the FRONT • On the BACK • Overview of photosynthesis and cell respiration • Detailed reactions for photosynthesis and cell respiration • Connect Reactants and Products of each reaction • Connect all intermediates • Be able to start as light, trace your way through the reactions, and end as ATP! PHOTOSYNTHESIS • Performed by organisms. autotroph • This cellular process occurs in organelle called chloroplast plant . • Converts sunlight energy into chemical energy • It is an anabolic • CO2 and H2O are the • Glucose and O2 are the reaction. reactants products cells, in the CELLULAR RESPIRATION • Performed by organisms. autotroph & heterotroph plant • This cellular process occurs in & animal cells, mitochondria in the organelle called . • Glucose is stored energy for the cell. ATP is usable energy for the cell. • It is a catabolic • CO2 and H2O & ATP are the • Glucose and O2 are the reaction. products reactants CHECK YOUR UNDERSTANDING! • BTB is a chemical that is blue when it is completely surrounded by oxygen. • BTB is a chemical that is yellow when it is completely surrounded by carbon dioxide. • A snail and aquatic plant were placed in a tube with blue BTB, and then placed in a dark room for four hours. This image represents what happed at each hour. • What process is occurring?
