Modeling Enzyme Activity

(15 pts) Introduction: Today, you are going to model enzyme activity. One partner will be the enzyme; you will be using the thumb, forefinger and middle finger on one hand to break toothpicks in half with your eyes closed. The other partner will be the timer and toothpick counter; you will be recording the data. Procedure: 1. Divide your flat toothpicks 4 even piles. Don’t bother counting them. Just eyeball it. 2. Activity 1: Spread out the first pile of toothpicks in front of you. I will time you for 30 seconds and you will see how many toothpicks you can break WITHOUT LOOKING AT THE TOOTHPICKS. Enzymes don’t have eyeballs after all. Put any leftover toothpicks to the side. Record your data 3. Activity 2: Spread out the second pile of toothpicks in front of both of you. Here is where your buddy comes in. Both of you will be breaking toothpicks for this activity. I will time you for 30 seconds to see how many toothpicks you both can break combined. Put any leftover toothpicks aside. Record your data 4. Activity 3: Spread out the third pile of toothpicks in front of you. Mix in an equal amount of round toothpicks into your pile. You must only break the flat toothpicks and in order to determine whether the toothpick is round or flat, you MUST pick it up. I will time you for 30 seconds to see how many flat toothpicks you can break. Put any leftover toothpicks aside. Record your data. 5. Activity 4: Spread out the last pile of toothpicks on the table in front of you. Tape the thumb of your dominant hand to your pointer knuckle. (you should not be able to move your thumb). I will time you for 30 seconds and you will see how many toothpicks you can break….no cheating!!! Put any leftover toothpicks aside. Record your data. Activity Number of Toothpicks Broken 1 2 3 4 Analysis Questions: Type your answers into the blue boxes below 1. During these activities, what represented the substrate, the enzyme, the reactants and the products? (So you should have 4 separate answers: one for substrate, one for enzyme, one for reactants and one for products) (2 pts) 2. Calculate the rates of reaction for each activity. Rate of reaction is the total number of toothpicks broken divided by the total time. Answers should be in decimal form with appropriate units. Please show your work (6 pts) Activity 1: Activity 2: Activity 3: Activity 4: 3. Write the activities in order of fastest reaction rate to slowest. (1 pt) 4. Identify which activity represents a reaction with noncompetitive inhibitors. Describe the results of introducing a noncompetitive inhibitor to the reaction and its reaction rate. (2 pts) 5. Identify which activity represents a reaction with competitive inhibitors. Describe the results of introducing a competitive inhibitor to the reaction and its reaction rate. (2 pts) 6. Identify the activity that represents increasing the concentration of the enzyme. Describe the results of increasing the enzyme concentration and its reaction rate. (2 pts) Background Info: Photosynthesis happens in plant leaves and it is broken down into two parts called the light dependent reactions and the Calvin Cycle. The reaction for photosynthesis is: 6 CO2 + 6 H2O → C6H12O6 + 6 O2 During this lab you will be seeing how the type of water that a leaf is in can affect the rate of photosynthesis. In order to do this, we’ll hole punch some spinach leaves (the little pieces are called chads), sink them, and time how long it takes for them to float. Then you will calculate ET50, which is the estimated time it takes 50% of the leaf chads to float. Question: Will leaf chads in sodium bicarbonate water or distilled water photosynthesize faster? Hypothesis: Data Table: Time (min) Water With Sodium Bicarbonate Distilled Water Total # floating Total # floating 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Water With Sodium Bicarbonate ET50= ________________ Distilled Water ET50 = ________________ Enzyme Virtual Lab (20 pts) Intro: In the toothpickase activity, you learned about the effects of introducing an inhibitor (both competitive and non) as well as changing the enzyme concentration on the rate of an enzyme-catalyzed reaction. In this investigation, you will determine the effects of substrate concentration and pH on the rate of an enzyme-catalyzed reaction. Background: Amylase is an enzyme that catalyses the hydrolysis of starch into the sugar maltose. It is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion. Foods that contain large amounts of starch, like bread, may acquire a slightly sweet taste as they are chewed because amylase degrades that starch into sugar (maltose). Pre-Activity Questions: Identify the enzyme: ______________________________ Identify the substrate: ____________________________ Identify the product: _____________________________ Procedure: In the simulation, the program is going to measure the amount of product produced after the reaction has progressed for one minute, allowing you to compare rates of reaction by looking at the amount of end product. The simulation allows you to change two variables: pH level and amount of available substrate. Use the arrows under the test tubes to raise or lower the pH. You will actually have to click on the little piece of paper with the substrate and drag it over to the tube. Data from the simulation can be viewed by clicking on the computer monitor icon toward the left side in the simulation. This simulation does require FLASH player enabled. Let your teacher know if you need help enabling FLASH player. Enzyme Virtual Lab Simulation Run the simulation and collect data for each of the variables and complete the table below. Data Collection: Amount of Substrate pH 3 pH 5 pH 7 pH 9 pH 11 0.5 g 1.0 g 2.0 g 4.0 g 8.0 g Post Activity Analysis Questions: 1. Identify the independent and dependent variables. (HINT: there are 2 independent variables but only one dependent variable) (2 pts) 2. Create a line graph for this data. (HINT: each pH level should be its own line. Make sure to clearly label or color code your lines. Also, think about what your units should be on BOTH AXES) (6 pts) 3. Think about the relationship between the substrate and the product. a. What happens when you increase the amount of substrate? (2 pts) b. Predict what would happen if you used 20.0 g of substrate and explain your reasoning behind the prediction. (2 pts) 4. You tested 5 different pH levels in this simulation. a. What is the optimum pH level for this enzyme? How do you know? (2 pts) b. Make a prediction about what you think the reaction rate would look like at a pH of 2. (1 pt) 5. Enzymes found in the human body function most efficiently at the temperature of a typical cell, which is 37 degrees Celsius. Increases or decreases in temperature can significantly lower the reaction rate. a. What does this suggest about the importance of temperature-regulating mechanisms in organisms? (1 pt) b. What is going on with the enzyme itself to cause this decrease in reaction rate? (1 pt) 6. Imagine that you were able to add inhibitors to your test tubes in the simulation. a. Predict how much maltose would be formed if a competitive inhibitor was introduced at a pH of 9 with 2 grams of substrate and provide a reasoning for this prediction. (1 pt) b. Predict how much maltose would be formed if a noncompetitive inhibitor was introduced at a pH of 9 with 2 grams of substrate and provide a reasoning for this prediction. (1 pt) Photosynthesis Quiz (20 pts) Name: _________________________________ Using the above diagram, name the structure each letter is indicating: X: _________________________ Y: _________________________ Z: _________________________ The name for the whole thing seen in the box is _________________________ Circle the letter that corresponds with the correct answer. Each question only has one correct answer. 1. What does a cell need in order to complete the light dependent reactions? I. Carbon dioxide II. Light III. Oxygen IV. Water a. I only b. II only c. III only d. II and IV e. I, II, and IV 2. What are the inputs for the Calvin cycle? I. Carbon dioxide II. ATP III. Oxygen a. I only b. III only c. II and IV d. I, II, and V e. I and II IV. Water V. half of a glucose 3. Which of the following things is not involved in the production of NADPH? a. NADP reductase c. half of a glucose b. Electron transport chain d. Photosystem I 4. The primary function of the Phase 1 of the Calvin Cycle is a. To generate NADPH b. To “fix” carbon by taking it from a gas state to a solid state c. To fill the electron “hole” of the chlorophyll a’s d. To assist ATP synthase. 5. Which of the following is not a product of the light dependent reactions? a. Carbon dioxide b. Oxygen c. NADPH d. ATP 6. Which of the following is mismatched with its location? a. b. c. d. e. Light reactions-thylakoid membrane Electron transport chain-thylakoid membrane Calvin Cycle-stroma Splitting of water-thylakoid space ATP synthesis-double membrane surrounding chloroplast 7. A photosystem is made of I. Pigments II. Integral Proteins a. b. c. d. e. III. ATP Synthase IV. Electron transport chain I and II I and III III and IV I, II, and III I, II, III and IV 8. The Calvin Cycle produces a. Carbon dioxide, ATP and NADP+ b. Oxygen, ADP, NADPH c. Glucose, ATP and water d. A 3 carbon sugar, ADP and NADP+ 9. Why is the hydrogen concentration gradient across the thylakoid membrane important for photosynthesis? a. Without it ATP wouldn’t be made b. Without it the electrons wouldn’t move properly c. Without it water wouldn’t split apart to produce oxygen d. Without it NADPH wouldn’t be made 10. How are the light dependent reactions and the Calvin Cycle interdependent? (2 pts) 11. On the line below, write the balanced chemical equation for photosynthesis. (2 pts) ________________________________________________________________________________________ 12. To synthesize one glucose molecule, the Calvin Cycle uses ______________ molecule(s) of CO2. (1 pt) 13. Why did the spinach chads float in the bicarbonate water? Why didn’t they float in the distilled water (be specific!) (2 pts) Virtual Photosynthesis Disc Lab Make sure you have printed off the lab handout from PSL watched the pre-lab procedure video, do that now. 3 Read through the background info on your lab handout Before you start the lab, write out your hypothesis. Make sure it is in if/then/because format. Take a look at the data table. 4 Explanation of the data table: You will be keeping a running tally of how many leaf chads are floating every minute. So if after one minute none are floating you will write a zero down. If between minutes 1 and 2 three chads rise to the surface, then you would put a three in for minute 2. If no more chads rose over the next 5 minutes, then you would fill in minutes 3-7 with a 3. Keep in mind you will be keeping track of 2 beakers!! (only one column of the data table shown here for demonstration purposes) 5 Watch the Video to See the Lab and Collect Your Data 6 Once you have your ET 50s, go to the class spreadsheet below and enter it in https://docs.google.com/spreadshe ets/d/1Jc6q2XW1NFXDDLd33cWt NP54BLztvrlbTJTtB7L5jY/edit#gid=0 7 That’s it for today. We’ll continue with the lab all together in class tomorrow. …
Purchase answer to see full attachment