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Enzyme Lab Experiments Problem: How can we demonstrate how enzymes work? What happens if we alter the environment of an enzyme? Materials: G;lucose Test StripsTest TubesPipettesRaw HamburgLettucePotato Raw LiverChalkBeakersDairy Lactose TabletWaterSugar Solo Cups Hot PlateKnifeGlovesSkim MilkGlow SticksPeroxide Hypothesis: 1. If we change the environment via temperature the glow stick will Its intensity will change 2. If hydrogen peroxide is added to a certain food liver then It would bubble 3. If a lactaid enzyme to milk the It would separate Procedure (A): 1. Collect three glow sticks. 2.
Boil water in 400 mL beaker add 1st glowstick for 30 minutes. 3. Place second glowstick in freezer for 30 minutes 4. Leave third glow stick at room temperature for 30 minutes 5. Observe and record findings. Data Collected (A): Place a glow stick in each environment below. Using a scale 1-3 1 being normal intensity 3 being brightest intensity BeakerObservation Freezer1 Boiling Water3 Room Temperature (control)2 Procedure (B): 1. Collect sample of raw liver, potato, raw hamburg, lettuce and chalk. 2. Place each sample in individual test tube in rack. 3. Observe samples prior to adding peroxide. 4.
Add 1 mL of peroxide to each test tube 5. Observe and record findings Data Collected (B): Reaction after hydrogen peroxide is added. Using a scale of 0-5 0 Being no bubbles 5 being the most bubbles Test tubeObservation before adding hydrogen peroxideObservation after adding hydrogen peroxide # 1 liverDark brown in color (expired meat)5 # 2 potatoInner slice with some skin2 # 3 raw hamburgNormal in color4 # 4 lettuceFresh green lettuce1 # 5 chalk Yellow colored chalk0 Procedure (C): Preparation: 1. Enzyme Solution: Add one lactase tablet to 200 ml of water. Stir until the tablet is dissolved. . Skim Milk: This solution contains lactose. 3. Sucrose Solution:Add 5 grams of sugar to 100 ml of water. Stir until the sugar is dissolved. 4. Denatured enzyme Solution: 1. Place 20 ml of enzyme solution into a test tube. 2. Add 200 ml of water to a 400 ml beaker. 3. Place the test tube in the beaker. Make sure it does not spill out. 4. Place the beaker and the test tube on a hot plate. 5. Boil the water for 30 minutes. 6. Let the solution cool to room temperature. Procedure (C-1) 1. Collect 6 mL of skim milk, place 2mL in each test tube (3 test tubes of skim milk). . Collect 4mL of sucrose solution, place 2mL in each test tube (2 test tubes total). 3. Observe and record initial observations. 4. Add 1mL of enzyme solution to a skim milk test tube; add 1mL of water to 2nd skim milk test tube, ad 1mL denatured enzyme solution to 3rd skim milk test tube. 5. Add 1mL of enzyme solution to 1st test tube of sucrose solution; add 1mL of water to 2nd test tube of sucrose solution. 6. Insert Glucose test strip in wch test tube (5 total). Wait 2 minutes. 7. Observe and record whether or not glucose is present and how much.
Test tubeInitial ObservationGlucose Test strip: Is glucose present 1. 2 ml of skim milk and 1ml of the enzyme solutionBubbles3000 Glucose 2. 2 ml of skim milk and 1 ml of waterNo bubbles 2 layers300 Glucose 3. 2 ml of skim milk and 1 ml of denatured solutionBubbles and layers 0 Glucose 4. 2 ml of sucrose solution and 1 ml of enzyme solutionClear liquidYellow in color zero glucose 5. 2 ml of sucrose solution and 1 ml of waterClear liquid Yellow in color no glucose What happens when the enzyme is denatured? The Enzyme does not work. Result Questions: 1. In which beaker did the glow stick glow the most?
Why do you think that is? The beaker that contained hot water. The heat from the water will speed up the chemical rate of reaction taking place, and therefore will glow brighter; the cold one will have its rate of reaction slowed, and thus be dimmer. 2. What did the glow stick show about enzymes and different environments? How does changing the temperature affect the rate of an enzyme-controlled experiment? The increasing temperature increases molecular motion and may increase the number of times an enzyme contacts and combines with a substrate molecule.
Temperature may also influence the shape of the enzyme molecule, making it fit better with the substrate. 3. What effect may change in PH have on an enzyme activity? The three-dimensional structure of a protein leaves certain side chains exposed. These side chains may attract ions from the environment. Under the right conditions, a group of positively charged hydrogen ions may accumulate on certain parts of an enzyme. A change in pH disrupts an enzyme’s shape and structure. When the pH changes an enzyme’s structure, the enzyme can’t do its job. Changes in pH break the delicate bonds that maintain an enzyme’s shape.
An enzyme will unravel, or denature, and become useless in a different pH. Stomach enzymes work in a super acidic environment of pH 2. A little way down the digestive tract, intestine enzymes need a pH of 8. 4. Why did the hamburger and liver react differently with hydrogen peroxide? They have natural catalase enzymes which were broken down with the presence of hydrogen peroxide. 5. What is the job of the lactase enzyme? Lactase is an enzyme which breaks down lactose, a sugar found in milk and other dairy products. 6. In which test tubes was the glucose present? Why?
In test tube #1 the enzyme broke down the lactose . Lactose is a disaccharide of glucose and galactose. The lactose tablet contained lactase which hydrolyzed the lactose into constituent galactose and glucose. Glucose is naturally occurring in skim milk thus in test tube # 2 found in a much smaller amount than test tube #1. 7. What happened when the enzyme was denatured or altered by heat? Did it work the same? Was glucose present? There was no glucose present. It did not work at all. Summary: What the class learn today about the jobs of enzymes? What questions does the class still have?