Lab 3 - Enzymes

Lab 3 - Enzymes - TODAY Turn in: Experiment topic Exam 1...

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Unformatted text preview: TODAY Turn in: Experiment topic Exam 1 Next Week! Student Presentations ENZYMES lecture Investigation Description Scenario Start Lab 3 Investigation 4 as a class, then split Investigation up and do 1-3 as tables up Today’s Lab Today’s Enzymes Enzymes are PROTEINS! PROTEINS! Structure and Shape of a folding result from: • Hydrophobic amino acids • Hydrogen bonds • Ionic attraction • Environment • pH • Temperature More Enzyme examples More Enzymes in chemical reactions Enzymes How does it work? Substrate Substrate Active Site Enzyme Products Active Site Enzymes in chemical reactions Enzymes How does it work? “LOCK AND KEY” Active Site Substrate Enzyme Enzymes in chemical reactions Enzymes How does it work? e.g. Polysaccharides into e.g. monosaccharides monosaccharides Products Active Site The Enzyme is not The changed! changed! Enzyme Products Enzymes Enzymes Enzymes act as Enzymes CATALYSTS in chemical reactions chemical A catalyst speeds up a speeds chemical reaction BUT chemical isn’t used up during the reaction the Energy costs Energy More Enzyme examples More What else can enzymes do? What DNA repair MSH2 Bring molecules together Transport materials across membranes Hormone control Active Site Acetylcholinesterase Enzyme examples ACETYLCHOLINESTERASE Released by nerve cells React with part of muscle cells React This is how our brain tells our muscles to contract Breaks lactose (milk sugar) into smaller monosaccharides for Breaks digestion digestion Lactose intolerant people lack this enzyme Breaks starch (polysaccharide) into monosaccharides for Breaks digestion digestion We will use this enzyme today LACTASE AMYLASE What effect does temp have on rate of reaction? rate Extreme heat denatures the enzyme!! It becomes inactive Substrate Enzyme Active Site pH is a measure of pH What effect does pH have on rate What of reaction? of hydrogen concentration, therefore, hydrogen bonds bonds Enzyme shape is Enzyme controlled by hydrogen bonds bonds Enzyme shape is Enzyme essential to function essential What effect does pH have on rate of reaction? of H+ + Substrate + H+ H+ H+ H+ H+ H+ Enzyme + ­ H+ What effect does concentration have on rate of reaction? have Substrate Enzyme Enzyme NOT used up in the reaction!! Enzyme Therefore as concentration increases, so Therefore should the rate of reaction! should ENZYMES Summary ENZYMES Group of proteins Each has a unique shape Speed up chemical reactions Regulated by numerous factors Temperature pH Concentration Names end in -ase Investigation 1,2 and 3 Investigation AMYLASE – an enzyme Breaks down starch (substrate) into simple sugars Breaks (products) (products) Amylase- starch (polysaccharide) into glucose Amylase(monosaccharide) (monosaccharide) What effect does concentration (1), temperature (2) What and pH (3) have on the rate at which amylase can rate break down starch (rate of reaction)? break Use iodine to test for the presence of starch What are the positive and negative controls? What are the dependent and independent variables? Senerio Senerio Exxon Valdez oil spill http://www.unu.edu/unupress/unupbooks/uu21le/uu21le0c.jpg Bioremedation Bioremedation “ The process of using living organisms to convert hazardous pollutants into less toxic compounds.” toxic Microorganisms break down organic Microorganisms molecules into carbon dioxide & water molecules They need O, N, P, & C http://www.bugsatwork.com/XYCLONYX/EPA_GUIDES/BIO.PDF Read the Scenario & Discuss Read Question 1:What substance allowed for bioremediation to take place? Question 2: Why was it important to use microorganisms native to the area? Question 3: Why was bioremediation preferred? Question 4: Can you pollute your gas tank @ a gas station with soil treated w/ bioremediation? Read the Scenario & Discuss Read Question 1:What substance allowed for bioremediation to take place????? Answer 1: Enzymes Question 2: Why was it important to use microorganisms native to the area??? Answer 2: Better for maintaining ecosystem balance, evolved for conditions present Question 3: Why was bioremediation preferred?? Answer 3: more efficient & less wasteful & creates less pollutants. Question 4: Can you pollute your gas tank @ a gas station with soil treated w/ bioremediation? Investigation 1 Investigation Assign the 3 different concentrations among Assign your groups your What are the positive and negative controls? Make sure you record exact time including Make seconds when you mix amylase with starch Assign a time keeper to let you know the exact Assign amount of time that has passed amount REMEMBER: Iodine is toxic to the REMEMBER: environment . Dispose in waste container environment Investigation 2 Investigation Effect of temperature on amylase reaction Effect rates rates Each bench will assign a different Each temperature to each group (cold, warm, hot) hot) Keep amylase and starch separate until Keep you begin your reaction (watch time) you Make sure you use color coded Make thermometers to avoid contamination thermometers Investigation 3 Investigation Choose which groups at your bench will Choose do each pH experiment do May want to have one time-keeper for all May reactions? reactions? Make sure you add acids/bases to the Make amylase solution prior to adding starch amylase Why do we add tap water to the neutral Why solution? solution? Begin Investigations Find your bench number on board and do Find investigations in that order investigations Let me know if you have any questions ...
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