Respiration Part 1 Worksheet F23

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Apr 3, 2024

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For today’s lab, you will complete this worksheet using the Vernier LabQuest 3 units and the carbon dioxide probes to compare the rates of cellular respiration among experimental groups. You might wish to investigate whether one organism has a faster rate of metabolism than another, or you might wish to determine whether a certain environmental change slows one organism’s metabolism. The choice of organism and the choice of hypothesis is entirely up to your team! Note that, just like with your CURE report, you are not expected to investigate all possible combinations of variables this week. Instead, you will work together with your team to develop a hypothesis, choose one model organism (or possibly two , depending on your hypothesis), and set up an experiment to test your hypothesis, using the skills you have acquired thus far in BIOL 241 and 243. Next week, you will work with your team to complete many trials of your experiment. By completing many trials, you will increase your confidence that your results are demonstrative of a real phenomenon, and not just random chance. Remember to upload this worksheet to Blackboard before the posted deadline. The feedback your GTA provides will help you refine our experiment next week in lab and run more trials of your experiment. INTRODUCTION Metabolism is the sum of all the chemical reactions in an organism. This includes catabolic chemical reactions that break down molecules for energy and anabolic chemical reactions that are constructive. Typically, the energy released from catabolic reactions is used for anabolic reactions in an organism. Cellular respiration is the metabolic process of converting the chemical energy of organic molecules into ATP, Team Members Present: 1.(lead author) Emma Farr 2.Ryan 3.Klay 4. WEEK 11 LEARNING OUTCOMES By the end of this lab you will be able to • Relate metabolism to photosynthesis and cellular respiration • Compare photosynthesis and cellular respiration • Predict factors that affect cellular respiration rate • Estimate rates of cellular respiration by measuring carbon dioxide production • Recall experimental design vocabulary from BIOL 241 • Recognize standardized variables Group members present: Respiration (Part 1) Week 11, BIOL 243 *Photo from University of Maryland Extension

the energy currency of the cell. In aerobic respiration , which requires oxygen to occur, glucose is oxidized completely according to the following equation: C 6 H 12 O 6 + 6O 2 --> 6H 2 O + 6 CO 2 + energy Recall that photosynthesis is, in some ways, the opposite of cellular respiration. Instead of using glucose and oxygen to make carbon dioxide, water, and energy, photosynthesis uses carbon dioxide, water, and solar energy to make glucose and oxygen! Is cellular respiration an anabolic or catabolic reaction? What about photosynthesis? ( 0.5 pt ) Both cellular respiration and photosynthesis are actually a series of reactions that rely on enzymes at each step. The equation given above for cellular respiration just summarizes the process overall, rather than revealing the specific steps taken by each enzyme along the way. Recall from BIOL 241 that enzymes are proteins that function over a limited range of conditions. Considering what you know about enzymes, what environmental factors might affect the rate of cellular respiration in an organism? ( 0.5 pt ) If an environmental factor was causing an organism’s cellular respiration rate to increase, which would occur (select all that apply)? ( 0.5 pt ) Oxygen consumption would increase Oxygen production would increase Carbon dioxide consumption would increase Carbon dioxide production would increase As you learned in your prelab for today, all sorts of organisms complete cellular respiration to produce the energy they need to survive; however, organisms vary in how much energy they need. Many characteristics of the organism itself affect its energy need: Is the organisms young and growing, or is the organism an adult? Is the organism active or not? Is the organism caring for young or not? Is the organism injured or not? Is the organism an endotherm or an ectotherm? Is the organism large or small? As an organism needs more energy, their basal metabolic rate – and cellular respiration rate – will increase to accommodate that need for more energy (i.e., more ATP). As that need decreases again, their cellular respiration rate will decrease as well. Below are several pairs of organisms that a researcher might like to compare in an experiment to determine which organism of the pair has a higher metabolic rate – or higher energy needs per Cellular respiration is a catabolic reaction involved in breaking down glucose into smaller molecules, such as ATP which gives them energy. Photosynthesis is an anabolic reaction. Cell type, pH, light availibility, CO2 levels, and water content.

gram of mass. Using the knowledge you gained in your prelab, identify which organism in each pair needs more energy (per gram of mass). ( 1 pt ) Pair One: A small endotherm A large endotherm Pair Two: A growing seed A dormant seed Pair Three: A bee resting in its hive A bee working in its hive Pair Four An ectotherm in a cold room An endotherm in a cold room Notice that, for all of the pairs being compared above, some things were standardized . What is the purpose of standardized variables in an experiment? ( 0.5 pt ) We’ll focus on aerobic respiration today in lab, which is the process your model organisms will be completing. A model organism is a species that is studied as a model to understand the biological processes in other species. We briefly list your options for model organism below. Some of the information you may already know, and you can also look up information about these species than what’s provided below, if you need it for your experiment. • Isopods (pill bugs & sowbugs) – These two distinct (but closely related) species are both crustaceans found in Phylum Arthropoda. They are ectothermic animals. Their body sizes vary: some are large, some are small. Isopods also have gills, so they are sensitive to changes in moisture. • Darkling beetles (adults & larvae) – Also called flour beetles, this species is a type of insect found in Phylum Arthropoda. They are ectothermic animals. The larvae (or growing young) are called mealworms. They use a tracheal system to respire, rather than gills. • Peas (dormant & germinating) – These seeds are the same species. The germinating seeds have been soaked in water and are starting to grow roots. The dormant seeds are not growing. Peas are autotrophic plants, but they have not begun photosynthesizing yet. They exchange respiratory gasses across their seed coats. • Pothos (leaves) – A familiar species of plant that you used in BIOL 241. Remember that, as an adult, Pothos plants are undergoing both cellular respiration and photosynthesis, simultaneously. Pothos leaves have stomata on their surfaces, where gas exchange occurs. This is your first open-inquiry lab. Your team will choose the question you want to investigate, based on your prelab work and our review above about all the factors that affect cellular respiration (and metabolic) rates in plants and animals. We encourage you to think like a scientist by determining the question you’d like to pursue first and then selecting a model organism (or organisms) appropriate for investigating that question. Once you’ve determined your question, model organism(s) and specific hypothesis, the prompts in this worksheet will help you set up your experiment. We highly encourage you to seek feedback from your GTA throughout this lab, and BEFORE you begin collecting data! We want you to get great data this week. Great data only Standardized variables are important in an experiment to see how the independent and dependent variables interact with each other and to know no other factors are affecting the results. Something that stays constant between all trials.

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comes from a great experimental set-up. Be sure your GTA signs off on that set-up before you go too far. While creating your CURE assignment in BIOL 241 and BIOL 243, you learned a set of skills that will allow you to formulate and test a hypothesis, chose the appropriate statistic test to analyze your data set, and then effectively report your results in a proper scientific format. The introduction and pre-lab have given you the background information. You have been provided lab tools and model organisms. Now, your team will ask a question, then formulate and test a hypothesis to address your question. Next week, you will run more trials of your experiment, to increase your confidence in your results. MATERIALS • Laptop computer • Vernier LabQuest 3 • Vernier CO 2 gas sensor probes • BioChambers (two sizes available to choose from): o 250 mL o 2000 mL • Parafilm • Rubber stoppers • Experimental materials you may (or may not) choose to use (in the interest of time, don’t use all of them to test multiple hypotheses this week): o Spray bottle of water o Paper towels o Heating pad o Ice bath • Model organisms to choose from (you may only need one or two organisms; in the interest of time, don’t use all of them to test multiple hypotheses this week): o isopods (pillbugs and sowbugs) o darkling beetles ( Tenebrio , also called flour beetles) o darkling beetle larvae (mealworms) o dormant peas o germinating peas o Pothos leaves PART 1: FORMING YOUR HYPOTHESIS As you have learned, the first step of any scientific experiment is a question or a problem to solve. Scientists will use past studies and their own knowledge to form questions and hypotheses. However, intuition, creativity and sometimes serendipity are also important elements of the scientific method. Taking what you know about plant and animal cellular respiration, devise a question that can be answered using the provided study organisms and available lab equipment. Don’t be overcomplicated. Ask one question, only. Be direct and concise. Don’t create a question that asks more than one thing.

Remember from your prelab: for our purposes this week, a good controlled experiment manipulates one variable at a time and standardizes all other variables (if possible) that could impact the results. Write your question below: ( 1 pt ) Once you have chosen a question to pursue, your team should develop a hypothesis. Your hypothesis should directly address the question that you posed. When constructing your hypothesis, keep in mind the feasibility of testing that hypothesis, given the materials available this week in lab. Write your hypothesis below: ( 2 pt ) Once you have constructed your hypothesis and question, have your GTA check your work. Discuss with your GTA how you might improve your question and hypothesis. Make any needed edits above BEFORE you proceed to the next part of this worksheet. ( 0.5 pt ) Question & Hypothesis Check Confirmation (to be completed by GTA ): lewis Now that you’ve had feedback from your GTA regarding your question and hypothesis, let’s use Google Scholar to find two sources and report their full citation. Note: you can use your textbook as a source, if you like! Source 1 full citation, APA format: ( 0.5 pt ) Source 2 full citation, APA format: ( 0.5 pt ) PART 2: DESIGNING YOUR EXPERIMENT The next step is your experimental design. How will you test your hypothesis? Remember all the questions to consider, which we reviewed in your prelab: How many replicates do you need? Do you need a control group (s)? If so, what will it/they be? What is your independent (or experimental) variable ? What variables are you standardizing among your groups? What is your dependent (response) variable ? How will you measure your dependent variable (including units )? What steps can you take to reduce bias or error in your experiment? What graph type How does cellular respiration of germinating peas change with an ice bath? The cellular respiration of germinating peas decreases in response to colder temperatures of an ice bath because they are ectothermic. We hypothesize that germinating peas are ectothermic. Therefore, the cellular respiration of germinating peas decreases in response to an ice bath. Responses of plants to low, nonfreezing temperatures: Proteins ... (n.d.). https://www.annualreviews.org/doi/abs/10.1146/annurev.pp.33.060182.002023 Williams, C. M. (2014, April 10). Cold truths: How winter drives responses of ... - Wiley Online Library. https://onlinelibrary.wiley.com/doi/full/10.1111/brv.12105

would best depict your data? What variable goes on the x-axis? What variable goes on the y-axis? What are your units for these variables? What is the dependent variable for all of the experiments today? What are its units? ( 2 pt ) Based on your hypothesis, what is your independent variable? What materials will you use today (given what’s available) to vary your independent variable between your control and experimental groups – or among experimental groups? ( 2 pt ) Describe your control and experimental groups here. What distinguishes them from each other? What is standardized (or the same) between them? ( 2 pt ) Are your groups paired or not? (Use your prelab for help here.) Based on your answer, prepare your data table in Excel . Label your columns, remembering that our Shiny app website does not like spaces between words! ( 1 pt ) How many replicates of your experiment do you plan to run? (NOTE: It’s okay if you only do one replicate – or trial – this week in lab. You can do the rest in the second week of the lab) ( 1 pt ) Once you have planned your experiment, have your GTA check your work. Discuss with your GTA how you might improve your experimental set-up. Is it feasible with the resources and time you have? Does it test your hypothesis? Is your data table formatted correctly, given the nature of your data (paired or not paired)? Make any needed edits above BEFORE you proceed to the next part of this worksheet. ( 0.5 pt ) Experimental Design Check Confirmation (to be completed by GTA): cousteau PART 3A: DATA COLLECTION - GENERAL PROTOCOL Everyone should begin their experimental set-up here. This is our general protocol, which includes instructions that all lab teams should follow, regardless of their hypothesis. Eventually in this general protocol, you’ll reach a point where you will need to refer to the protocol(s) specific to your team’s hypothesis and choice of model organism(s). Once you reach that point, we’ll let you know where to go next – like a Choose Your Own Adventure story! 1. Make sure the LabQuest 3 is plugged in. Turn on the LabQuest 3 with the blue power button on the top left of the unit. cellular respiration, ppm/second Colder temperatures. Ice, CO2 probe, labquest Our control group is the group with room temperature and no factors are effecting the rates of cellular respiration. Our experimental group is the group using the ice bath and colder temperatures to determine their rates of cellular respiration. Biomass is our standardized variable. Our groups are unpaired. one of each trial for this week.

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2. Depending on which CO 2 sensor probe you have, its cord will either have a clip-in (like a phone jack) or a USB plug to attach to the LabQuest 3. Plug the CO 2 sensor into the appropriate plug on the left side of the Lab Quest 3. The unit should recognize the CO 2 probe and give you a reading. 3. If you are using the large BioChamber, place the CO 2 gas sensor probe into the BioChamber as shown in figure at right (Figure 1). Also, use a strip of parafilm to seal the lid of the chamber to the base. If it is not needed, also snugly plug the empty hole in your BioChamber lid with a rubber stopper (Figure 1). 4. If you are using the 250mL BioChamber, make sure the probe fits snugly into the mouth of the bottle. You may not be able to completely insert the probe, but make sure the holes in the probe are completely inserted (Figure 2). 5. Record the temperature in the room with your thermometer, even if you are not testing for temperature effects. 6. Time to Choose Your Own Adventure! Go to the individual protocols on pages 8-9 (i.e., PART 3B of this lab worksheet) for preparation and placement of your specific model organism(s) into the BioChamber(s). Return here when your specimens are in their chamber(s) . 7. Before taking any data, wait 3 minutes for readings to stabilize on your LabQuest 3. At the end of this waiting period, you should have a reading on your LabQuest 3 of 300-900 PPM of CO 2 . If you’re reading is a little outside of this range, that’s okay. If it’s significantly outside this range, alert your GTA. 8. While you’re waiting, use the thermometer to measure the room temperature. Record the temperature in your data table (on Excel). 9. To start data collection, click the green button on the LabQuest 3. Feel free to leave the collection interval and axis labels on the LabQuest 3 the same as default. But, if you wish to change the default settings, then you can tap the screen to adjust the sampling interval and duration. 10. Each trial should run at least 10 minutes. Figure 1: The large BioChamber (2000 mL) Figure 2: The small BioChamber (250 mL)

11. When your 10-minute data collection is complete, click the red stop button on the LabQuest 3 display. All experiments should use rates of carbon dioxide production as the response variable. The data you need to record from the LabQuest 3 to demonstrate the rate of change in CO 2 over time is the slope of the best-fit line through the data points that you collect. You will determine the rate of CO 2 production by clicking “Analyze” and then “Curve Fit”. The slope of the line (m) represents the rate of change. 12. Once data collection is complete, turn off your LabQuest 3. If you used the light chambers, turn off the lights in your light chamber and carefully unplug your CO 2 probe from the LabQuest 3 unit. If you used parafilm, remove it from your lid and place it in the trash. 13. If you used Pothos, remove the plant leaves from the BioChamber and place them in the trash. 14. DO NOT throw away live animals, including the peas !! Return all other specimen to their appropriate “used” container. 15. Dry your BioChamber with paper towels and dispose of the paper towels in the trash. 16. Record your data in your data sheet on Excel. Be sure to save it! 17. Proceed to Part 4 of this lab worksheet to create your graph! PART 3B: DATA COLLECTION - INDIVIDUAL PROTOCOLS The protocol that you use for data collection will depend upon your question and hypothesis. Below, navigate to the protocols that align with your choice of model organism . Isopods and darkling beetles (our animals, specifically arthropods): 1. If your team decides to use these live animals, then please note: these animals should be treated with the utmost respect and care. For your protection and theirs, always wear gloves when handling live animals.

2. The animals will attempt to escape, be careful not to squash them. If you mistreat the live animals, you will be asked to immediately leave lab . 3. The live specimen will be stressed. Handle them as little as possible. If you are using the same specimen for multiple trials, rest them at least 10 minutes between trials. Do not place any live animal directly on ice or a heating source . 4. Place a 250ml BioChamber on the scale and tare the scale. 5. Obtain enough individuals to weigh about 1 gram (10 pill bugs; 7 darkling beetle adults, 7-10 mealworms depending on size). Place them in the 250 mL respiration chamber. 6. Weigh the specimen and record the weight in your data table. If needed, carefully transfer your specimen to the BioChamber 2000. Otherwise, insert the CO 2 probe as shown in Figure 3. 7. Return to the general protocol from here (Part 3A). Peas and Pothos (our plants, specifically angiosperms): For Peas: 1. Obtain 25 germinating peas and blot them dry between two pieces of paper towel. 2. Weigh the specimen and record the weight in your data table. The weight should be close to 10 grams. 3. Place the germinating peas into the BioChamber (Figure 4). 4. Place the CO 2 gas sensor probe into the BioChamber as shown in figure at right (Figure 4). 5. Return to the general protocol from here (Part 3A). For Pothos leaves: 6. Obtain 3 or 4 pothos leaves from the plants on the front table in your lab room and weigh them. Your leaves should weigh close to 5 grams. 7. If you want to include the effects of photosynthesis , also get the small watering tubes for each leaf. If the leaves are damp, blot them dry between two pieces of paper towel. Use Figure 3: Seven adult darkling beetles in a small BioChamber (250 mL) Figure 4: Ten grams of germinating peas in a small BioChamber (250 mL)

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the sink to fill the small watering tubes with tap water (this won’t take long, given the small size of the tubes). Cut the stem of each leaf at an angle, and place each cut stem in a tube. 8. Spray the bottom of your BioChamber with water. Be sure the CO 2 probe is out of the way; it cannot get wet. 9. Line the bottom of the BioChamber with damp paper towels. 10. Carefully place the leaves into your BioChamber, with the darker green surface facing upwards. Try to lay the leaves as flat as possible in the chamber, overlapping as little as possible. 11. If you wish to exclude the effects of photosynthesis , then at this point, carefully cover the BioChamber with the plastic pots provided to keep the environment inside your BioChamber dark (away from light). 12. Place the CO 2 gas sensor probe into the BioChamber as shown in Figure 1. 13. Return to the general protocol from (Part 3A). PART 4: GRAPH YOUR DATA Use Excel to make a bar or box-and-whisker plot of the data you’ve collected so far, as you’ve learned to do in BIOL 241. For help, refer to the video from BIOL 241 on how to make a box-and- whisker plot. Bar graphs are made by a similar procedure. If you’ve only run one trial of your experiment during lab this week, that’s just fine! Go ahead and format a graph and caption displaying the data from your single trial. That way, your GTA can provide feedback on your plans for how your graph will ultimately look once you have data from all your trials completed. Label your axes appropriately. Use the CURE report rubric as a guide. Then, upload an image of your graph below. ( 2 pts )

Compose a caption for this figure below. Use your CURE report rubric for guidance. ( 2 pt ) KEEP YOUR EXCEL FILE WITH ALL THE DATA FROM THE TRIALS YOU COMPLETED TODAY. You’ll need it next week in lab, as you will conduct more trials next week and add your data to this Excel and graph. PART 5: DATA ANALYSIS No need to run the statistical test this week! You’ll need all your data trials completed before you’re ready for that step. You can run it during the second week of this lab, once you’re done collecting data on all your trials. As a head start, feel free to visit our new statistics website for you lab here: https://abolins.shinyapps.io/biostats3/ You’ll notice that now you select whether your data are “paired” or “unpaired” on the website, when you run your statistic tests: And once again: DO NOT THROW AWAY LIVE SPECIMENS, including peas!! Save them on the back lab bench for future teams to use. As a general rule, always leave the lab as you found it for the next section. Figure 1: Cellular Respiration Rates (ppm) of Germinating Peas and How Temperature has an Effect on These Rates

Respiration Part 1 Worksheet F23

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