Science Biology Unit 05 Exemplar Lesson 01: Energy Conversions

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1 Science Unit: 05 Lesson: 01 Suggested Duration: 8 days Science Unit 05 Exemplar Lesson 01: Energy Conversions This lesson is one approach to teaching the State Standards associated with this unit. Districts are encouraged to customize this lesson by supplementing with district-approved resources, materials, and activities to best meet the needs of learners. The duration for this lesson is only a recommendation, and districts may modify the time frame to meet students needs. To better understand how your district may be implementing CSCOPE lessons, please contact your child s teacher. (For your convenience, please find linked the TEA Commissioner s List of State Board of Education Approved Instructional Resources and Midcycle State Adopted Instructional Materials.) Lesson Synopsis In this lesson, students will investigate, compare, and contrast the processes of photosynthesis and cellular respiration. TEKS The Texas Essential Knowledge and Skills (TEKS) listed below are the standards adopted by the State Board of Education, which are required by Texas law. Any standard that has a strike-through (e.g. sample phrase) indicates that portion of the standard is taught in a previous or subsequent unit. The TEKS are available on the Texas Education Agency website at B.4 Science concepts. The student knows that cells are the basic structures of all living things with specialized parts that perform specific functions and that viruses are different from cells. The student is expected to: B.4B Investigate and explain cellular processes, including homeostasis, energy conversions, transport of molecules, and synthesis of new molecules. Readiness Standard B.9 Science concepts. The student knows the significance of various molecules involved in metabolic processes and energy conversions that occur in living organisms. The student is expected to: B.9B Compare the reactants and products of photosynthesis and cellular respiration in terms of energy and matter. Scientific Process TEKS Supporting Standard B.1 Scientific processes. The student, for at least 40% of instructional time, conducts laboratory and field investigations using safe, environmentally appropriate, and ethical practices. The student is expected to: B.1A Demonstrate safe practices during laboratory and field investigations. B.1B Demonstrate an understanding of the use and conservation of resources and the proper disposal or recycling of materials. B.2 Scientific processes. The student uses scientific methods and equipment during laboratory and field investigations. The student is expected to: B.2E B.2F Plan and implement descriptive, comparative, and experimental investigations, including asking questions, formulating testable hypotheses, and selecting equipment and technology. Collect and organize qualitative and quantitative data and make measurements with accuracy and precision using tools such as calculators, spreadsheet software, data-collecting probes, computers, standard laboratory glassware, microscopes, various prepared slides, stereoscopes, metric rulers, electronic balances, gel electrophoresis apparatuses, micropipettors, hand lenses, Celsius thermometers, hot plates, lab notebooks or journals, timing devices, cameras, Petri dishes, lab incubators, dissection equipment, meter sticks, and models, diagrams, or samples of biological specimens or structures. B.2G Analyze, evaluate, make inferences, and predict trends from data. B.2H Communicate valid conclusions supported by the data through methods such as lab reports, labeled drawings, graphic organizers, journals, summaries, oral reports, and technology-based reports. B.3 Scientific processes. The student uses critical thinking, scientific reasoning, and problem solving to make informed decisions within and outside the classroom. The student is expected to: B.3E Evaluate models according to their limitations in representing biological objects or events. GETTING READY FOR INSTRUCTION Performance Indicators Last Updated 04/29/2013 page 1 of 40

2 High School Science Unit 05 PI 01 Compare and contrast photosynthesis and respiration by constructing an illustration comparing the energy and matter flow in both processes. Write a summary describing the illustration including a balanced chemical equation for both processes. Standard(s): B.2H, B.4B, B.9B ELPS ELPS.c.1C, ELPS.c.4K, ELPS.c.5G Key Understandings Some organisms are capable of converting light energy into chemical energy (glucose) through photosynthesis. Science Unit: 05 Lesson: 01 Suggested Duration: 8 days What organisms carry out photosynthesis? What is the process of photosynthesis? What are the products and reactants for photosynthesis? Organisms extract energy from glucose to produce ATP. What is the process that cells use to extract energy from glucose to produce ATP? What are the products and reactants of cellular respiration? Vocabulary of Instruction photosynthesis cellular respiration chloroplasts chlorophyll aerobic respiration anaerobic respiration Calvin cycle glycolysis Krebs cycle ATP (Adenosine Triphosphate) Materials aprons (1 per student) balloon (small, 6 7 size, 1 per group) Bromothymol blue solution (12 15 drops per group of 2 students) Bromthymol blue indicator solution (10 drops per group) calculators (1 per student) cellophane (colored, at least 1 roll each of various colors, per teacher) clock or stop watch (1 per group) dropper (1 per group of 2 students) dry rapid rise yeast (4 g per group) electronic scale (4 5 per class to share) Elodea plant (3 sprigs per group of 2 students) Elodea sprigs (3 per group) foil (large piece, 1 per group of 2 students) glue or tape (per group) graduated cylinder (25 ml, 1 per group of 2 students) labeling pencil (1 per group of 2 students) light source (window or lamp, 1 2 locations per class) light sources (various wattage bulbs, lamps, sunlight, amount varies based on student selection of experiment, see Advance Preparation) markers, crayons, and/or colored pencils (per group) marking pencil (1 per group) masking tape (long piece, 1 per group) ph probe and software (1 per lab group) poster board (large, 1 per student) ruler (metric, 1 per group) safety goggles (1 per student) sodium bicarbonate solutions (0.5%, 1%, 1.5%, 2%, see Advance Preparation, various amounts) sodium bicarbonate (baking soda, at least one small box per class, for solutions) water (per class, for solutions) stopwatch or clock with a second hand (1 per group) straws sugar (8 g per lab group) tape measure (metric, 1 per group) temperature probe or thermometer (2 3 per class, with software) test tube racks test tube stoppers (3 per group of 2 students) test tubes (large, 1 per group) test tubes (small, 2 per group) water Attachments All attachments associated with this lesson are referenced in the body of the lesson. Due to considerations for grading or student assessment, Last Updated 04/29/2013 page 2 of 40

3 Science Unit: 05 Lesson: 01 Suggested Duration: 8 days attachments that are connected with Performance Indicators or serve as answer keys are available in the district site and are not accessible on the public website. Teacher Resource: Photosynthesis Vocabulary Card Sort Cards (see Advance Preparation, 1 class set an Handout: Observing Photosynthesis in Elodea (1 per student) Teacher Resource: Observing Photosynthesis in Elodea KEY Handout: Photosynthesis Research and Notes (1 per student) Teacher Resource: Photosynthesis Research and Notes KEY Teacher Resource: PowerPoint: Photosynthesis Notes Handout: Investigating Factors Affecting Photosynthesis (1 per student) Teacher Resource: Investigating Factors Affecting Photosynthesis KEY Handout: Observing Cellular Respiration in Yeast (1 per student) Teacher Resource: Observing Cellular Respiration in Yeast KEY Handout: The Effect of Exercise on Cellular Respiration and Production of Carbon Dioxide (1 per stud Teacher Resource: The Effect of Exercise on Cellular Respiration and Production of Carbon Dioxide KE Handout: Cellular Respiration Animation Notes (1 per student) Teacher Resource: Cellular Respiration Animation Notes KEY Handout: Comparing Photosynthesis and Cellular Respiration PI (1 per student) Teacher Resource: Performance Indicator Instructions KEY Resources None Identified Advance Preparation 1. Prior to Day 1, print the cards from the Handout: Photosynthesis Vocabulary Card Sort Cards onto cardstock, and then laminate, cut out, and bag them. You will need one class set with one set for each student. 2. Prior to Day 1, obtain all of the materials, including Elodea, for the Observing Photosynthesis in Elodea investigation. Bromothymol blue indicator solution can be purchased from scientific supply companies. The 0.04% aqueous solution will work for this investigation. 3. Prior to Day 1, arrange for access to student computers/internet and/or print materials for research. Review the Teacher Resource: Photosynthesis Research and Notes KEY to determine what resources you will allow your students to use for the activity. 4. Prior to Day 4, obtain all of the investigation materials for the student designed lab and make the sodium bicarbonate solutions following these formulas: 0.5%: Dissolve 0.5 g of sodium bicarbonate (baking soda) into 99.5mL of water. 1%: Dissolve 1 g of sodium bicarbonate (baking soda) into 99.0 ml of water. 1.5%: Dissolve 1.5 g of sodium bicarbonate (baking soda) into 98.5 ml of water. 2%: Dissolve 2 g of sodium bicarbonate (baking soda) into 98 ml of water. You will need at least 50 ml of the 1% solution for every lab group. The other solution amounts will depend upon how many students select to test amount of CO 2 as their factor. On Day 3, record what each lab group will be testing so that you can provide the correct amount of materials on Day 4. Additional teacher notes can be found in the Teacher Resource: Investigating Factors Affecting Photosynthesis KEY. 5. Prior to Day 5, obtain all of the materials needed for the cellular respiration: yeast lab and exercise investigation. 6. Prior to Day 6, arrange for a projection system to display the animation on cellular respiration to the class. Preview the animation in preparation for the discussion. Review the Teacher Resource: Cellular Respiration Animation Notes KEY to determine what animation(s) you will need for the activity. Locate and preview animation(s) in preparation for the discussion. 7. Prepare attachments as necessary. Background Information This lesson bundles student expectations that address energy conversions related to photosynthesis and cellular respiration. Prior to this unit, students learned the basic components of the cell. During this unit, students will learn how the machinery of the cell accomplishes photosynthesis and cellular respiration and they will form an understanding of the two reactions that allow them to compare products and reactants of photosynthesis and respiration. After this unit, students will use the cellular processes discussed in this unit during upcoming units, including evolution, viruses and bacteria, plants, and body systems. STAAR Notes: The student expectations for the STAAR Assessment covered in this unit include Readiness Standard B.4B and Supporting Standard B.9B. Although this content may be reinforced throughout the year, this will be the last time these concepts are explicitly taught before the test. INSTRUCTIONAL PROCEDURES Last Updated 04/29/2013 page 3 of 40

4 Instructional Procedures ENGAGE Energy Conversions Notes for Teacher NOTE: 1 Day = 50 minutes Suggested Day 1 Science Unit: 05 Lesson: 01 Suggested Duration: 8 days 1. Display the word Photosynthesis on the board as students walk into the room. As each student enters the room, give them a set of cards from the Teacher Resource: Photosynthesis Vocabulary Card Sort Cards (see Advance Preparation). 2. When students are seated with their cards, instruct them to place the cards into whatever groups make sense to them (They may sort hard vs. easy or words I know vs. words I don t know; etc.). It is important to instruct students that there is NO RIGHT ANSWER. This activity is a formative pre-assessment for you to help you determine students prior knowledge, their familiarity with the vocabulary, and weaknesses they may have in this lesson. Give students a few minutes to sort the cards, and then ask for a few volunteers to share how they sorted their cards. 3. Facilitate a short, introductory discussion about photosynthesis with students. Ask: What is photosynthesis? Student answers will vary, but based on their prior experience in Grade 7, they may answer that it is a process that changes energy from the Sun into chemical energy (food) for the plant. They may also know that photo means light. They may recall chlorophyll and chloroplasts from Grade 7. What organisms conduct photosynthesis? Student answers will vary, but they will likely know that plants conduct photosynthesis from their prior experiences in middle school. Some may remember that certain protists, such as algae, also conduct photosynthesis. If plants get their energy/food from photosynthesis, how do animals get their energy/food? Student answers will vary, but they will likely say by eating plants and/or animals. Attachments: Teacher Resource: Photosynthesis Vocabulary Card Sort Cards (see Advanced Preparation,1 class set and 1 set per student) Instructional Notes: As students complete the card sort, circulate through the room to determine their sorting method and see if they have any misconceptions that will need to be addressed throughout this lesson. Use the activity as a time to see which students seem to have the best background knowledge with these concepts, so they can be paired with students who have less background knowledge during subsequent activities. Misconception: Students may think that cellular respiration only occurs in animals and does not occur in other organisms, such as plants. 4. Use this time as an opportunity to introduce the concept of cellular respiration. Display the words Cellular Respiration on the board. Briefly explain to students that animals and plants both use this process to break down glucose (sugars) from food into a form that their cells can use. Explain that, in this lesson, they will be learning how photosynthesis and cellular respiration help organisms get the energy they need. EXPLORE Energy Conversions 1. Divide the class into groups of two. Distribute the Handout: Observing Photosynthesis in Elodea to each student. 2. Review the background information with students, and explain that this investigation will allow them to observe photosynthesis in the water plant Elodea. 3. Review safety precautions (see Safety Notes), and clean up measures with students. Remind students to use resources wisely, including the recycling of any recyclable materials, such as the foil. 4. Students will set up this investigation today and then leave their setup overnight. At the beginning of Day 2, students will observe their setup, record their data, and analyze the results. Use the analysis questions to conduct a brief discussion of the lab with students. Suggested Day 1 (continued) Materials: Elodea plant (3 sprigs per group of 2 students) light source (window or lamp, 1 2 locations per class) Bromothymol blue solution (12 15 drops per group of 2 students) labeling pencil (1 per group of 2 students) dropper (1 per group of 2 students) test tubes (able to hold at least 25 ml, 3 per group of 2 students) test tube stoppers (3 per group of 2 students) water (per group) test tube racks (several per class, placed in light and dark areas) straw (1 per student) graduated cylinder (25 ml, 1 per group of 2 students) foil (large piece, 1 per group of 2 students) safety goggles (1 per student) aprons (1 per student) Attachments: Handout: Observing Photosynthesis in Elodea (1 per student) Teacher Resource: Observing Photosynthesis in Elodea KEY Safety Notes: Last Updated 04/29/2013 page 4 of 40

5 Students should wear safety goggles and lab aprons during this investigation. Science Unit: 05 Lesson: 01 Suggested Duration: 8 days In addition, remind students of the proper disposal of materials at the completion of the investigation on Day 2. Stress to students to only blow gently through the straws, not to suck in. Instructional Notes: Bromothymol blue indicator solution can be purchased from scientific supply companies. The 0.04% aqueous solution will work for this investigation. In addition, remind students of the proper disposal of materials at the completion of the investigation on Day 2. Stress to students to only blow gently through the straws, not to suck EXPLAIN Energy Conversions Suggested Days 1 (continued) and 2 in. 1. Divide the class into small groups of two. You may wish for students to remain with their lab partner from the Explore activity. Consider pairing stronger readers with less strong readers. 2. Distribute the Handout: Photosynthesis Research and Notes to each student. Provide Internet access, websites, and textbooks/other print materials to help students complete this handout (see Advance Preparation). 3. Encourage students to complete as much of the handout as possible, using their research materials. Allow students research time for the remainder of Day 1 and for the first minutes of Day Circulate and assist students as needed as they complete their research. 5. Use the Teacher Resource: PowerPoint: Photosynthesis Notes to review the handout with students. Facilitate a discussion of the information throughout. During the review and discussion, be sure to ask the questions located in the Notes section of the PowerPoint. 6. Students should revise and/or add to their handouts based on the information in the presentation and additionally from the discussion. During the discussion, be sure to ask the questions included in the Notes section of the PowerPoint. 7. By the end of Day 2, students should be able to answer the following questions: What organisms carry out photosynthesis? Autotrophs, such as plants and some protists, carry out photosynthesis. What is the process of photosynthesis? Photosynthesis is the cellular process in which autotrophs capture light energy and convert it to chemical energy (glucose) using carbon dioxide and water. What are the products and reactants for photosynthesis? (The products in photosynthesis are glucose (sugar) and oxygen. The reactants in photosynthesis are carbon dioxide, water, and light energy.) 8. At the end of Day 2, instruct students to record in their science notebooks the equation, reactants, and products for photosynthesis. You may also wish to have students affix their investigation handout and notes handouts in their notebooks. Materials Attachments: glue or tape (per group) Handout: Photosynthesis Research and Notes (1 per student) Teacher Resource: Photosynthesis Research and Notes KEY Teacher Resource: PowerPoint: Photosynthesis Notes Instructional Note: Photosynthesis is a difficult concept, and some students may need assistance in understanding the material they are reading. Check For Understanding: Ensure students are able to answer Guiding Questions. STAAR Notes: The student expectations for the STAAR Assessment covered in this unit include Readiness Standard B.4B and Supporting Standard B.9B. Although this content may be reinforced throughout the year, this will be the last time these concepts are explicitly taught before the test. Science Notebooks: Students record the equation, reactants, and products for photosynthesis and affix handouts in their notebooks. ELABORATE Energy Conversions Suggested Days 3 and 4 1. Inform students that over the next two days, the class will be designing and implementing an investigation of the factors that affect photosynthesis. 2. Divide the class into small lab groups of 2 3. Distribute the Handout: Investigating Factors Affecting Photosynthesis to each student. 3. Review background information on the handout and expectations with students. Review safety precautions and proper disposal of materials information. 4. Remind students that their experimental design/procedures must be approved before they may begin their experiment. Materials test tubes (3 per group) test tube racks (1 per group) Elodea sprigs (3 per group) sodium bicarbonate solutions (0.5%, 1%, 1.5%, 2%, see Advance Preparation, various amounts) sodium bicarbonate (baking soda, at least one small box per class, for solutions) Last Updated 04/29/2013 page 5 of 40

6 5. Ask: What are some factors that might affect photosynthesis? Amount of carbon dioxide available, intensity of light, color of light, and/or temperature 6. Inform students that they will be selecting one factor to investigate and they need to keep all other factors constant throughout their experiment. Review independent and dependent variables with students. 7. Demonstrate to students how to remove a few leaves from the bottom of the Elodea plant, crush the stem, and then place it inverted into a test tube. Inform students this is the method they will need to use for their experiment. 8. At the conclusion of the investigation, ask for volunteers to share their procedures and their results. Science Unit: 05 Lesson: 01 Suggested Duration: 8 days water (per class, for solutions) light sources (various wattage bulbs, lamps, sunlight, amount varies based on student selection of experiment, see Advance Preparation) ph probe and software (1 per lab group) cellophane (colored, at least 1 roll each of various colors, per teacher) warm water bath (1 2 per class) temperature probe or thermometer (2 3 per class, with software) ruler (metric, 1 per group) safety goggles (1 per student) aprons (1 per student) calculators (1 per student) Attachments: Handout: Investigating Factors Affecting Photosynthesis (1 per student) Teacher Resource: Investigating Factors Affecting Photosynthesis KEY Safety Notes: Students should wear safety goggles and lab aprons during this investigation. Instruct students on the proper disposal of all materials per your classroom setup. Instructional Notes: Prepare the different concentrations of baking soda solutions prior to Day 3, following the instructions in the Advanced Preparation section. Additional teacher notes can be found in the Teacher Resource: Investigating Factors Affecting Photosynthesis KEY. EXPLORE Energy Conversions Suggested Day 5 Science Notebooks: Students affix handouts in their notebooks. 1. Inform students that today they will be conducting an investigation to observe cellular respiration in yeast. 2. Divide the class into groups of two. Distribute the Handout: Observing Cellular Respiration in Yeast to each student. 3. Review background information on the handout and expectations with students. Review safety precautions and proper disposal of materials information. 4. Remind students that cellular respiration is a process that both plant and animal cells use to obtain useable energy from their food. 5. Monitor and assist students as they complete the investigation. 6. At the conclusion of the activity, facilitate a discussion of the following: What was the food for the yeast? Sugar What gas caused the balloon to inflate? Carbon dioxide caused the balloon to inflate. What gas do humans expel when they breathe? Humans expel carbon dioxide. Take this time to remind students that cellular respiration happens in both plant and animal cells and is not the same as breathing. Animal cells have the product of carbon dioxide when they go through cellular respiration, and this waste product is then expelled from their bodies through the process of breathing. 7. Instruct students to remain in their groups, and distribute the Handout: The Effect of Exercise on Cellular Respiration and Production of Carbon Dioxide to each Materials: dry rapid rise yeast (4 g per group) balloon (small, 6 7 size, 1 per group) masking tape (long piece, 1 per group) test tubes (large, 1 per group) sugar (8 g per lab group) clock or stop watch (1 per group) tape measure (metric, 1 per group) electronic scale (4 5 per class to share) warm water (about ml per group) test tubes (small, 2 per group) graduated cylinder (25 ml, 1 per group) marking pencil (1 per group) Bromthymol blue indicator solution (10 drops per group) straws (1 per student) stopwatch or clock with a second hand (1 per group) safety goggles (1 per student) aprons (1 per student) glue or tape (per group) Attachments: Last Updated 04/29/2013 page 6 of 40

7 student. Remind students to only blow through the straws, not to suck in, during this investigation. 8. Monitor and assist students as they complete the investigation. 9. At the conclusion of the investigation, use the analysis questions to conduct a brief discussion about the lab and ask students to reflect on what they have learned. 10. Instruct students to affix their handouts in their notebooks. Science Unit: 05 Lesson: 01 Suggested Duration: 8 days Handout: Observing Cellular Respiration in Yeast (1 per student) Teacher Resource: Observing Cellular Respiration in Yeast KEY Handout: The Effect of Exercise on Cellular Respiration and Production of Carbon Dioxide (1 per student) Teacher Resource: The Effect of Exercise on Cellular Respiration and Production of Carbon Dioxide KEY Safety Notes: Students should wear safety goggles and lab aprons during both lab activities. Instruct students on the proper disposal of all materials per your classroom setup. Misconceptions: Students may think that cellular respiration only occurs in animals and does not occur in other organisms, such as plants. Students may think that respiration refers only to breathing. EXPLAIN Energy Conversions Suggested Day 6 1. Inform students that today they will be exploring an online animation on cellular respiration (see Advance Preparation). 2. Distribute the Handout: Cellular Respiration Animation Notes. 3. Inform students that you will view the animation together and they will fill in information about cellular respiration as they watch the animation. 4. Use a projection system to go over your choice of animation with students, pausing as needed to discuss and give students time to fill in their handout. Alternatively, you may wish to provide print resources for students to complete the activity. 5. Make sure to include Glycolysis, Krebs Cycle, and Electron Transport Chain. 6. Use the following questions in the discussion: What is the process that cells use to extract energy from glucose to produce ATP? What are the products and reactants of cellular respiration? 7. At the conclusion of the animation discussion, ask: The animation/simulation we viewed was a good tool or model of cellular respiration; however, all models have limitations. What are its limitations? Student answers will vary. Encourage students to evaluate the use of animations/simulations and determine how they are helpful even given their limitations. Materials: Attachments: glue or tape (per group) Handout: Cellular Respiration Animation Notes (1 per student) Teacher Resource: Cellular Respiration Animation Notes KEY Instructional Notes: If you have the computer/internet access capability, you may wish to have students view animation(s) and fill in their handouts in small groups. Then, have a class discussion to ensure each student understands the processes, products, and reactants of cellular respiration. Science Notebooks: Students record the equation, reactants and products for cellular respiration in their science notebooks. 8. At the end of Day 6, have students record the equation, reactants, and products for cellular respiration in their science notebooks. Additionally, instruct students to affix their handouts in their notebooks. EVALUATE Performance Indicator Energy Conversions Suggested Days 7 and 8 High School Science Unit 05 PI 01 Compare and contrast photosynthesis and respiration by constructing an illustration comparing the energy and matter flow in both processes. Write a summary describing the illustration including a balanced chemical equation for both processes. Standard(s): B.2H, B.4B, B.9B ELPS ELPS.c.1C, ELPS.c.4K, ELPS.c.5G Materials: poster board (large, 1 per student) markers, crayons, and/or colored pencils (per group) Last Updated 04/29/2013 page 7 of 40

8 1. Refer to the Teacher Resource: Performance Indicator Instructions KEY and Handout: Comparing Photosynthesis and Cellular Respiration PI for information on administering the assessment. Attachments: Science Unit: 05 Lesson: 01 Suggested Duration: 8 days Handout: Comparing Photosynthesis and Cellular Respiration PI (1 per student) Teacher Resource: Performance Indicator Instructions KEY Last Updated 04/29/2013 page 8 of 40

9 Photosynthesis Vocabulary Card Sort Cards Instructions: Print and cut out a set of these cards for each student in the class. Consider printing them on card stock and laminating them for durability. Place each set into a resealable, plastic bag. SUN PLANT TREE FLOWER SUGAR O 2 (OXYGEN) ENERGY H 2 O (WATER) 2012, TESCCC 08/23/12 page 1 of 2

10 C 6 H 12 O 6 (GLUCOSE) CO 2 (CARBON DIOXIDE) CHLOROPLAST ATP CARBON CYCLE NADPH PHOTOSYNTHESIS MITOCHONDRIA 2012, TESCCC 08/23/12 page 2 of 2

11 Observing Photosynthesis in Elodea Objective: Observe the process of photosynthesis in Elodea plants. Background: Photosynthesis is the cellular process in which autotrophs capture light energy and convert it to chemical energy (glucose) using carbon dioxide and water. The chemical reaction for photosynthesis is: Photosynthesis occurs within the chloroplasts of plant cells. Chloroplasts contain chlorophyll that capture the energy from light. Within the chloroplasts, water is split into hydrogen and oxygen atoms, and then through a series of chemical reactions, the hydrogen forms with carbon dioxide in the plant and forms glucose (sugar). Oxygen is released by the plant into its environment. Materials: safety goggles lab aprons Elodea plant (3 sprigs) light source (window or lamp) Bromothymol blue solution dropper labeling pencil 3 test tubes (able to hold at least 25 ml) 3 test tube stoppers test tube rack straw (1 per student) graduated cylinder (25 ml) foil (large piece) water Procedures: 1. Wear your safety goggles and lab aprons throughout the investigation. 2. Label your test tubes #1, #2, and #3 and with your group name/initials. 3. Cover the outside of test tube #2 with foil. Ensure all of the test tube is covered. 4. Measure and pour 15 ml of water into each of the three test tubes. 5. Add 3 5 drops of Bromothymol blue indicator solution to test tube #1. 6. Using your straw, gently blow into the test tube until you notice a color change to yellow. Do not suck in through the straw. The indicator solution turned yellow because you blew carbon dioxide into the test tube. You have added carbon dioxide to the environment in the test tube. Remember that plants use carbon dioxide to carry out photosynthesis. 7. Place a sprig of Elodea and then a stopper into the test tube. Place test tube #1 in a test tube rack near sunlight or a lamp, and record the appearance of test tube #1 in the data chart. 2012, TESCCC 08/23/12 page 1 of 3

12 8. Add 3 5 drops of Bromothymol blue indicator solution to test tube #2. Using your straw, gently blow into the test tube until you notice a color change to yellow. Place a sprig of Elodea and then a stopper into the test tube. Place test tube #2 in a test tube rack in a dark location, as instructed by your teacher. Record the appearance of test tube # 2 in the data table. 9. Add 3 5 drops of Bromothymol blue indicator solution to test tube #3. Using your straw, gently blow into the test tube until you notice a color change to yellow. Place a stopper in the test tube, and then place test tube #3 in a test tube rack near sunlight or a lamp. Record the appearance of test tube #3 in the data table. 10. Leave the test tubes overnight. At the beginning of class tomorrow, collect your test tubes and record your observations in the data table below. 11. Clean up your materials according to your teacher s instructions. Dispose of your materials appropriately. For example, recycle the aluminum foil. 12. Answer the analysis questions. 2012, TESCCC 08/23/12 page 2 of 3

13 Data Table: Test Tube # Initial Observation Observation After 24 Hours Analysis Questions: 1. Which test tube(s) showed a color change? 2. What does a change in color indicate? 3. Based on your observations during this lab, what is required for a green plant to carry out photosynthesis? Justify your answer. 2012, TESCCC 08/23/12 page 3 of 3

14 Observing Photosynthesis in Elodea KEY Data Table: Test Tube # Initial Observation Observation After 24 Hours 1 Yellow color Should see a change back to blue color 2 Yellow color Yellow color should remain. 3 Yellow color should remain. Yellow color should remain. Analysis Questions: 1. Which test tube(s) showed a color change? Test tube #2 showed a color change from yellow to blue. 2. What does a change in color indicate? The color change means that the plant used up the carbon dioxide in the test tube while carrying out photosynthesis. Since the carbon dioxide was used up, the indicator solution went back to its original blue color. 3. Based on your observations during this lab, what is required for a green plant to carry out photosynthesis? Justify your answer. A green plant must have light and carbon dioxide to carry out photosynthesis. The plant in the test tube that was covered and in the dark did not carry out photosynthesis, so the solution stayed yellow. The plant in the light (test tube #1) did carry out photosynthesis, and it used carbon dioxide while doing so because a color change was observed. Students may also indicate the presence of chlorophyll from past experience. 2012, TESCCC 08/23/12 page 1 of 1

15 Photosynthesis Research and Notes Objective: Research and gain knowledge of photosynthesis: its purpose, reactants, and products. Instructions: Use the resources provided by your teacher to complete this handout. Questions: 1. What is chemosynthesis? What types of organisms carry out chemosynthesis? 2. What type of organisms carry out photosynthesis? 3. What is photosynthesis? 4. What is the chemical equation for photosynthesis? (Write in chemical equation and word form.) 5. What are the reactants in photosynthesis? 2012, TESCCC 04/19/13 page 1 of 2

16 6. What are the products in photosynthesis? 7. Where does photosynthesis occur? 8. Describe the light dependent reaction of photosynthesis. Where does it occur? 9. The light independent reaction is also known as the Calvin Cycle. Describe the light independent reaction of photosynthesis. Where does it occur? What are its reactants and products? 2012, TESCCC 04/19/13 page 2 of 2

17 Photosynthesis Research and Notes KEY Advance Preparation: Locate and preview websites prior to class to determine resources appropriate for your students needs. Student answers will vary slightly, but should be similar to the following: Objective: Research and gain knowledge of photosynthesis: its purpose, reactants, and products. Instructions: Use the resources provided by your teacher to complete this handout. Questions: 1. What is chemosynthesis? What types of organisms carry out chemosynthesis? Chemosynthesis uses energy released from chemical reactions to produce food for organisms. Organisms that carry out chemosynthesis are microbes (bacteria) that live far from the sun, such as deep on the ocean floor. 2. What type of organisms carry out photosynthesis? Autotrophs such as plants and some protists carry out photosynthesis. 3. What is photosynthesis? Photosynthesis is the cellular process in which autotrophs capture light energy and convert it to chemical energy (glucose) using carbon dioxide and water. 4. What is the chemical equation for photosynthesis? (Write in chemical equation and word form.) 6CO 2 + 6H 2 O + light energy C 6 H 12 O 6 + 6O 2 Carbon dioxide + water + light energy yields glucose (sugar) and oxygen 5. What are the reactants in photosynthesis? The reactants in photosynthesis are carbon dioxide, water and light energy. 6. What are the products in photosynthesis? The products in photosynthesis are glucose (sugar) and oxygen. 7. Where does photosynthesis occur? Photosynthesis occurs in the chloroplasts. 8. Describe the light dependent reaction of photosynthesis. Where does it occur? The light dependent reaction of photosynthesis occurs in the thylakoid. The light dependent reaction requires sunlight to enter the chloroplasts and water to enter through the roots. It converts light energy to chemical energy, also called ATP. This energy helps to fuel the light independent reaction, or the Calvin Cycle. During the light dependent reaction, the Sun hits the chlorophyll and this energy splits water molecules into oxygen and hydrogen. The oxygen is released while the hydrogen is used to make NADPH (an electron carrier). The NADPH is also needed for the light independent reaction. 2012, TESCCC 04/19/13 page 1 of 2

18 9. The light independent reaction is also known as the Calvin Cycle. Describe the light independent reaction of photosynthesis. Where does it occur? What are its reactants and products? The light independent reaction or Calvin Cycle occurs in the stroma. This process converts CO 2 (carbon dioxide) and ATP into glucose (sugar). Carbon dioxide from the atmosphere enters the plant, and the H+ ion is broken off from the NADPH molecule. The NADP+ then returns to the light dependent reaction to pick up more hydrogen, while the H+ ions are fixed with the carbon dioxide, forming glucose. The reactants in the Calvin Cycle are carbon dioxide, ATP, and the electrons on NADPH. The product of the Calvin Cycle is glucose. Possible Resources: Websites are subject to changes and may have associated links that are neither referenced nor approved by CSCOPE. District personnel are encouraged to preview and vet all websites, resources, and references in accordance with district policy , TESCCC 04/19/13 page 2 of 2

19 Investigating Factors Affecting Photosynthesis Objective: Design an investigation to test how one factor may affect the rate of photosynthesis. Background: Recall that photosynthesis is the cellular process in which autotrophs capture light energy and convert it to chemical energy (glucose) using carbon dioxide and water. Photosynthesis requires water, carbon dioxide, and light energy. The products of photosynthesis are oxygen and glucose. One way to determine if photosynthesis has taken place is to measure the ph of a solution containing a water plant. If the CO 2 level in a solution decreases, the ph of the solution will increase. Another way to determine the rate of photosynthesis is to observe and count bubbles of oxygen being released from the plant. Experimental Design: You will be using the materials provided to test one factor that may affect photosynthesis. You will only need to use some of the materials listed, based on the factor you choose to test. Your experimental design will be written to answer the following question: How does affect the rate of photosynthesis? Possible factors to test include: amount/intensity of light, color of light, temperature and/or amount of carbon dioxide available. Prediction: When you have selected the factor you will test, write a prediction in your science notebook about how this factor will affect the rate of photosynthesis. You will have access to the materials listed below: test tubes test tube rack Elodea sprigs sodium bicarbonate solutions (0.5%, 1%, 1.5%, 2%) calculators light sources (various wattage bulbs, lamps, sunlight) ph probe and software colored cellophane warm water bath temperature probe or thermometer ruler (metric) safety goggles aprons 2012, TESCCC 08/23/12 page 1 of 2

20 Write your experimental design in your science notebooks. Include a diagram showing the setup of your experiment, describing how and what you will measure during your experiment. Your teacher must approve your experimental design before you can conduct your experiment. When your experimental design is approved, set up your experiment and collect your data. Test Tube Setup: The standard setup for a test tube (the control) for this experiment is as follows: 1. Fill a test tube about ¾ full with 1% sodium bicarbonate solution (baking soda solution). 2. Remove the leaves around the very bottom of one sprig of Elodea. Crush the stem end, then place the Elodea into the test tube, as demonstrated by your instructor. 3. Place a stopper in the test tube. Data Collection: Determine the best equipment and procedure to collect your data. Design and label a data table in your science notebooks to record your data. Use your data to create an appropriate graph to help explain the results of your experiment. Results/Analysis: In your science notebook, explain the results of your experiment and what you learned about how the factor you chose affects the rate of photosynthesis. 2012, TESCCC 08/23/12 page 2 of 2

21 Investigating Factors Affecting Photosynthesis Objective: Design an investigation to test how one factor may affect the rate of photosynthesis. Background: Recall that photosynthesis is the cellular process in which autotrophs capture light energy and convert it to chemical energy (glucose) using carbon dioxide and water. Photosynthesis requires water, carbon dioxide, and light energy. The products of photosynthesis are oxygen and glucose. One way to determine if photosynthesis has taken place is to measure the ph of a solution containing a water plant. If the CO 2 level in a solution decreases, the ph of the solution will increase. Another way to determine the rate of photosynthesis is to observe and count bubbles of oxygen being released from the plant. Experimental Design: You will be using the materials provided to test one factor that may affect photosynthesis. You will only need to use some of the materials listed, based on the factor you choose to test. Your experimental design will be written to answer the following question: How does affect the rate of photosynthesis? Possible factors to test include: amount/intensity of light, color of light, temperature and/or amount of carbon dioxide available. **Possible set ups could include: Varying the distance from the light source, varying the wattage of the bulb in the light source, covering the light source with colored cellophane, using different concentrations of sodium bicarbonate solution (varying the amount of CO 2 available), or varying the temperature of the solution. Remind students that they can only change ONE factor and review independent and dependent variables. Prediction: When you have selected the factor you will test, write a prediction in your science notebook about how this factor will affect the rate of photosynthesis. You will have access to the materials listed below: Students will design their experiments on Day 3. Based on which factors students decided to test, provide the appropriate amounts of the materials listed below: test tubes test tube rack Elodea sprigs sodium bicarbonate solutions (0.5%, 1%, 1.5%, 2%) light sources (various wattage bulbs, lamps, sunlight) ph probe and software colored cellophane warm water bath temperature probe or thermometer ruler (metric) safety goggles aprons calculators 2012, TESCCC 08/23/12 page 1 of 2

22 Sodium bicarbonate solution recipes: 0.5%: Dissolve 0.5g of sodium bicarbonate (baking soda) into 99.5ml of water. 1%: Dissolve 1g of sodium bicarbonate (baking soda) into 99.0 ml of water. 1.5%: Dissolve 1.5g of sodium bicarbonate (baking soda) into 98.5ml of water. 2%: Dissolve 2g of sodium bicarbonate (baking soda) into 98ml of water. Provide bulbs of various wattage (40W, 60W, 100W, etc.) Write your experimental design in your science notebooks. Include a diagram showing the setup of your experiment, describing how and what you will measure during your experiment. Your teacher must approve your experimental design before you can conduct your experiment. When your experimental design is approved, set up your experiment and collect your data. Test Tube Setup: The standard setup for a test tube (the control) for this experiment is as follows: 1. Fill a test tube about ¾ full with 1% sodium bicarbonate solution (baking soda solution). 2. Remove the leaves around the very bottom of one sprig of Elodea. Crush the stem end, and then place the Elodea into the test tube, as demonstrated by your instructor. 3. Place a stopper the test tube. Data Collection: Determine the best equipment and procedure to collect your data. Design and label a data table in your science notebooks to record your data. Use your data to create an appropriate graph to help explain the results of your experiment. Results/Analysis: In your science notebook, explain the results of your experiment and what you learned about how the factor you chose affects the rate of photosynthesis. 2012, TESCCC 08/23/12 page 2 of 2

23 Observing Cellular Respiration in Yeast Adapted from Respiration in Yeast by M. Poarch Objective: Observe cell respiration in yeast. Background: When cells take in oxygen and release carbon dioxide and energy, it is called respiration. In this process, glucose molecules are broken down and energy is released. Respiration happens in all living cells, and it can occur both day and night. The equation for cellular respiration is: C 6 H 12 O 6 + 6O 2 6CO 2 + 6H energy (Glucose + Oxygen yields Carbon Dioxide + Water + Energy) You may notice that the equation for cellular respiration is the opposite of the equation for photosynthesis. Most cells carry out the process of cellular respiration using oxygen (aerobic); however, some are anaerobic. Anaerobic organisms do not use oxygen to break down glucose or have limited supplies in which to carry out this task. The energy released from glucose is converted to ATP and is required for all cellular functions for the survival of the cell/organism. The organelle, where aerobic respiration takes place in the cell, is the mitochondrion. Anaerobic respiration (fermentation) takes place in the cytoplasm. In this investigation, you will work with yeast. Yeast is a one-celled fungus that reproduces rapidly under the right conditions with an ample food supply. Materials: dry rapid rise yeast test tubes (large) tape measure safety goggles balloon (small, 6 7 size) sugar warm water apron clock or stop watch electronic scale metric tape measure masking tape Procedure: 1. Wear safety goggles and an apron throughout the investigation. 2. Place 4 g of yeast and 8 g of sugar into a large test tube. 3. Fill test tube ¾ full of warm water (Be careful that it isn t too hot, or you will kill the yeast.). 4. Stretch a balloon over the opening of the test tube very QUICKLY. 5. Seal the balloon to the test tube using masking tape. 6. Shake the test tube to speed up the process, do this as needed to keep contents mixed. 7. Measure the diameter of the balloon every two minutes for a total of 20 minutes. Record data in the table provided. 2012, TESCCC 04/29/13 page 1 of 4

24 Data: Diameter of Balloon at Two Minute Intervals Time (minutes) Diameter (cm) , TESCCC 04/29/13 page 2 of 4

25 Data Analysis: Make a line graph of your data. Remember to keep in mind the differences between the independent and dependent variable when graphing, and don t forget to provide a title and label your axes. 2012, TESCCC 04/29/13 page 3 of 4

26 Analysis and Conclusion: 1. What was your evidence that cellular respiration was occurring? 2. What provided the energy (food) for the yeast to carry out cellular respiration? 3. What gas inflated the balloon? 4. What conclusion can you draw about how anaerobic respiration in yeast aids the making of bread? 2012, TESCCC 04/29/13 page 4 of 4

27 Observing Cellular Respiration in Yeast KEY Adapted from Respiration in Yeast by M. Poarch *Students should observe the balloon inflating as the yeast performs cellular respiration. They should see an increase in the diameter of the balloon. If they do not, they may have used water that was too hot. They should start over and use warm water the second time. Analysis and Conclusion: 1. What was your evidence that cellular respiration was occurring? The yeast was releasing a gas, causing the balloon to inflate. 2. What provided the energy (food) for the yeast to carry out cellular respiration? The sugar provided the energy for the yeast. 3. What gas inflated the balloon? CO 2 (carbon dioxide) is a product of cellular respiration, so it was the gas that inflated the balloon. 4. What conclusion can you draw about how anaerobic respiration in yeast aids in the making of bread? It releases the CO 2 gas, which helps the bread to rise and be fluffy. 2012, TESCCC 04/19/13 page 1 of 1

28 The Effect of Exercise on Cellular Respiration and Production of Carbon Dioxide Objective: Conduct an experiment to determine how exercise affects cellular respiration. Background: Cells in plants and animals must conduct cellular respiration to obtain useable energy for their functions. Cellular respiration uses oxygen to breakdown glucose into carbon dioxide, water, and energy. The rate at which carbon dioxide is produced can be used to determine the rate of cellular respiration. Materials: small test tubes (2) graduated cylinder (25 ml) marking pencil Bromthymol blue indicator solution straws (2) (1 per student) stopwatch or clock with a second hand safetygoggles aprons Prediction: How do you think exercise will influence or change the way your body produces carbon dioxide? Record your prediction: Procedure: 1. Label one test tube before and the other test tube after. 2. Measure and pour 15 ml of water into each test tube. 3. Put five drops of Bromthymol blue indicator solution into each test tube. 4. Prepare the stopwatch, or watch the clock. On your partner s signal, you will blow air slowly through a straw into the solution in the test tube labeled before. Caution: Do not suck in through the straw OR blow too hard into the straw. 5. When the solution becomes yellow in color, stop the timer and stop blowing into the test tube. Record the amount of time it took for the color change to happen. 6. Jog in place for one minute. 7. Immediately after jogging for one minute, repeat steps 4 & 5 using test tube marked after. 8. Discard your straw, and clean out both test tubes. (Follow teacher instructions for solution disposal.) 2012, TESCCC 04/29/13 page 1 of 3