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Cellular Respiration Lab Report Name Date Cellular Respiration Lab Report Directions: Complete each lab procedure in the order it is presented. Be sure to document your investigation by thoroughly completing each activity, such as filling in the tables, uploading any necessary photos or drawings, and answering each question. This lab will take place over two days. On the first day, you will germinate the pea seeds and explore the Rate of Respiration OLABS Activity. On the second day, you will assemble the respirometers and use them to measure the gas exchange from the germinated peas. Materials You will need the following materials to complete this lab: • absorbent cotton • dried pea seeds • eye protection goggles • eyedropper • glass beads (Plastic can be used if no glass beads are available.) • ice • KAH lye solution • latex or nitrile gloves • nonabsorbent cotton • paper towels • plastic bin or container • plastic syringes (4) • plastic ziplock bag Safety Note KAH lye is caustic, and will burn unprotected skin. Always wear gloves and goggles when handling it. © 2018 Pearson Online & Blended Learning K–12 USA. All rights reserved. © 2018 Pearson Online & Blended Learning K–12 USA. All rights reserved. 2 Day 1: Germinating Peas The seeds will take 2–3 days to germinate, so this step must be done immediately: 1. Gather your pea seeds, ziplock bag, and paper towels. 2. Soak a paper towel in warm water, then wring it out until it is damp but not dripping. 3. Empty half your pea seeds onto the paper towel (the other half will go into a respirometer ungerminated). 4. Fold the paper towel over the peas, then fold in the sides to create a pocket so the peas stay in place. 5. Slide the paper towel pocket into the bag and seal it. 6. Place the bag in a warm, out-of-the-way spot. Label the bag if necessary. Rate of Respiration OLABS Activity Use the link on the slide to access the Rate of Respiration OLABS Activity. Complete the activity. Be aware that the lab you will perform uses different materials and processes than the alternative online OLABS Activity. Now that you are familiar with one method use to measure the rate of cellular respiration, watch the AP Biology Lab 5 - Cellular Respiration video. Write down any notes in your notebook about the process of building and using a respirometer. Write Your Hypothesis The first step in any scientific inquiry is creating a hypothesis. Read over the following Respirometer activity. What results are you expecting to find? Use this space to write a hypothesis for the results you expect to see from this lab investigation. © 2018 Pearson Online & Blended Learning K–12 USA. All rights reserved. 3 Day 2: Building and Using Respirometers Building the Respirometer Once the pea seeds have germinated, follow these steps to build a set of four respirometers: 1. Use the link in the slide to access the Rate of Respiration OLABS activity and the AP Biology Lab 5 - Cellular Respiration Video. You do not need to do the activity again, but give it a quick review to refresh your memory. 2. Put on your gloves and goggles, and tie back any long hair. 3. Gather the plastic syringes, absorbent and non-absorbent cotton, and lye solution. 4. Take four pieces of absorbent cotton, soak them in the lye solution, and place one in each of the four plastic syringes. Be sure to keep your gloves and goggles securely in place during this step. 5. Take four pieces of nonabsorbent cotton and place one on top of the piece of lye-soaked cotton in each syringe. Make sure the nonabsorbent cotton is large enough to completely cover the lye-soaked cotton. Testing Gas Exchange Now you will use your respirometers to perform a cellular respiration experiment. 1. Gather the 4 respirometers, the germinated and ungerminated peas, the glass beads, a container for the water bath, and a cup of ice. 2. Place 25 germinated peas in the first syringe. 3. Place 25 germinated peas in the second syringe, then put this respirometer into the cup of ice. 4. Place 25 ungerminated peas in the third syringe. Use beads to make up any difference in volume between this respirometer and the first one. 5. Fill the fourth syringe with enough beads to match the volume of the other 3 syringes. This is your control. 6. Label the syringes (1–4) with a marker and masking tape. 7. Fill the container with 25-degree (Celsius) water. Place the respirometer with the germinated peas, the respirometer with the non-germinated peas, and the control respirometer into the water. Lower the respirometers in at an angle, let them rest at an angle for a few minutes to equalize, then lower them the rest of the way into the water. © 2018 Pearson Online & Blended Learning K–12 USA. All rights reserved. 4 8. Take an initial reading of the respirometers by measuring how far the fluid has moved into the syringe (in millimeters), and record the data on the table below. 9. Take an initial reading from the respirometer that is on ice. Record that data as well. 10.Take additional readings from all four respirometers after 5, 10, 15, 20, and 25 minutes. Respirometer Readings Germinated Peas (Room Temperature) Germinated Peas (Ice) Ungerminated Peas Beads (Control) Initial Reading 5 min. 10 min. 15 min. 20 min. 25 min. Cleaning Up Once you have recorded your data, clean up the area. Be sure to keep your gloves and goggles on until you have disposed of the lye-soaked cotton and anything it might have touched, and empty out the water and ice. Time © 2018 Pearson Online & Blended Learning K–12 USA. All rights reserved. 5 Lab Review 1) Look at the hypothesis you wrote on day 1 of this lab investigation. Does your data support this hypothesis? If not, how do the results alter your hypothesis? 2) Using the data from your table, create a graph that illustrates how the volume of gas produced in each respirometer changed over time. You can draw your graph in the space below, or upload a separate image. 3) Write your answers to the following questions. a. Could this same respirometer system be used to measure the rate of respiration in small invertebrates, such as insects or earthworms? © 2018 Pearson Online & Blended Learning K–12 USA. All rights reserved. 6 b. This investigation measured the respiration of ungerminated seeds and newly-germinated seeds. Based on this data, what would be the respiration in seeds at later stages of germination? c. This investigation focused on the respiration rate of a single type of seed, which stores its energy in sugar. However, other plants have seeds that store energy in oil. Some examples are sunflower seeds, sesame seeds, and nuts. What different respiration rates would you hypothesize from these seeds? d. Does temperature or germination time play a more important role in determining the respiration rate? Support your answer with data from your table, and explain why this is the case. e. How do your observations from this activity relate to the process of cellular respiration? Refer to reactants and products of the reaction in your response. Cellular Respiration Lab Report Materials Safety Note Day 1: Germinating Peas Cell Respiration Lab Bench Activity Write Your Hypothesis Day 2: Building and Using Respirometers Building the Respirometer Testing Gas Exchange Respirometer Readings Cleaning Up Lab Review Name: Date: Ungerminated PeasInitial Reading: Germinated Peas (Room Temperature) Initial Reading: Germinated Peas (Ice) Initial Reading: Beads (Control) Initial Reading: Germinated Peas (Room Temperature) 5 min: Germinated Peas (Ice) 5 min: Ungerminated Peas 5 min: Beads (Control) 5 min: Germinated Peas (Room Temperature) 10 min: Germinated Peas (Ice) 10 min: Ungerminated Peas 10 min: Beads (Control) 10 min: Germinated Peas (Room Temperature) 15 min: Germinated Peas (Ice) 15 min: Ungerminated Peas 15 min: Beads (Control) 15 min: Germinated Peas (Room Temperature) 20 min: Germinated Peas (Ice) 20 min: Ungerminated Peas 20 min: Beads (Control) 20 min: Germinated Peas (Room Temperature) 25 min: Germinated Peas (Ice) 25 min: Ungerminated Peas 25 min: Beads (Control) 25 min: Hypothesis Answer Space: Lab Review Answer Space: Button10: Question Space 3: Question Space b: Question Space c: Question Space d: Question Space e: