Unit 8: Energy Conversions in Cells Name: Period: Test Date: 1
Table of Contents Title of Page Page Number Due Date Unit 8 Warm-Ups 3-4 Notes 5-6 Chloroplast (Read and color) 7-8 Starch Production in Photosynthesis Lab 9-12 Photosynthesis Flow Chart Worksheet 13 Respiration Demos 14 Mitochondria (read and color) 15-16 Anaerobic Respiration Lab 17-19 Respiration and Photosynthesis Review 20 Unit 8 Vocabulary 21 2
UNIT 7 WARM-UPS Question: Date: Answer: Question: Date: Answer: Question: Date: Answer: Question: Date: Answer: Question: Date: Answer: 3
Question: Date: Answer: Question: Date: Answer: Question: Date: Answer: Question: Date: Answer: Question: Date: Answer: 4
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Photosynthesis Diagram and Label Aerobic Respiration Anaerobic Respiration 6
Chloroplast Read and Color Plant cells and some algae contain an organelle called the chloroplast. The chloroplast allows plants to harvest energy from sunlight to carry on a process known as photosynthesis. Specialized pigments in the chloroplast (including the common green pigment chlorophyll) absorb sunlight and use this energy to combine carbon dioxide and water and make GLUCOSE and OXYGEN. The complete the chemical reaction for Photosynthesis is: 6 CO2 + 6 H2O + energy (from sunlight) C6H12O6 + 6 O2 RAW MATERIALS ENERGY PRODUCTS In this way, plant cells manufacture glucose and other carbohydrates that they can store for later use. Photosynthetic cells, found mainly in the leaves, may have thousands of chloroplasts. Chloroplasts are double membrane organelles with a smooth outer membrane and an inner membrane folded into disc-shaped sacs called thylakoids. Color and label the outer membrane light green. Thylakoids, containing chlorophyll and other accessory pigments (red, orange, yellow, brown), are in stacks called granum (grana, plural). Color and label the grana (STACK) dark green in Figure 1. Grana are connected to each other by structures called lamellae, and they are surrounded by a gel-like material called stroma. Color and label the lamellae brown in figure 1. Color and label the stroma light blue in Figure 1. FIGURE 1-CHLOROPLAST 7
Light-capturing pigments in the grana are organized into photosystems. On Figure 2, color and label a single thylakoid (SINGLE DISK) dark green. In figure 2, color and label a granum (STACK) red. FIGURE 2-THYLAKOID 1. What is chlorophyll and where is it found? 2. Where is chlorophyll found in the chloroplast? 3. In which part of a plant would you expect to find the most chloroplasts and why? 3. Where does the energy for photosynthesis come from? 4. What are the raw materials for photosynthesis? 5. What simple sugar is produced? 6. What gas is USED? RELEASED? 7. How many membranes surround a chloroplast? 8
Starch Production in Photosynthesis Background: The ultimate source of energy used by living things comes from the sun. Autotrophs such as plants produce energy rich carbon compounds by converting radiant energy to chemical energy in the process of photosynthesis. Photosynthesis occurs inside a cell organelle called the chloroplast. The chloroplast is surrounded by a double membrane on the outside and stacks of membranes on the inside called grana. Each granum is made of stacks of sac-like membranes called thylakoids which contain the green pigment chlorophyll. Surrounding the grana is a gel-like matrix called the stroma. The stroma and thylakoid membranes are directly involved in the processes of photosynthesis. Fig.1 The reactions of photosynthesis can be divided into two main sets of events called the light-dependent and lightindependent or dark reactions. The light-dependent reactions occur in the membranes of the thylakoids and send their products to the stroma where the light-independent reactions take place. The light-independent reactions, called the Calvin cycle, convert carbon dioxide and water into glucose using energy from the light-dependent reactions. Figure 2 illustrates the basic processes of the Calvin cycle. Energy end products from the light-dependent reaction, such as ATP, supply the energy needed for the Calvin cycle. In the Calvin cycle, 6 carbon dioxide molecules are used to produce a single 6 carbon glucose. As glucose molecules become available, they are chemically combined through dehydration synthesis to create long chains of starch and cellulose. Starch is a common energy storage molecule in plant. These carbohydrates can be used by the plant to provide energy for cellular activities. Heterotrophs obtain this stored energy when they consume the plants as a food. Iodine is a specific stain for starch, producing a black color (actually a very dark blue) where starch is present. ergy Rich Carbohydrates 9
Purpose: In this activity, you will observe the use of the iodine-starch test to compare the amounts of starch produced in a leaf exposed to light with one that has been light-limited. Pre-lab Questions: 1. Hierarchy of Photosynthesis: Number the order of the diagrams in descending order (1=largest to 5= smallest) below to indicate where the Calvin Cycle takes place. Circle where the Calvin Cycle occurs. 2. What is the difference between the light-dependent and the light-independent (Calvin Cycle) reactions? 3. How do the light-independent reactions (Calvin Cycle) rely on the light-dependent reactions? Video: https://www.youtube.com/watch?v=vh3gvbx-djo&feature=youtu.be Procedure: Watch the video of the experiment making notes below. Materials needed: Brief procedure: 10
Observations: Draw a picture of your leaves indicating the different shades you observe. Diagram of Leaf exposed to sunlight (photosynthesizing leaf) Diagram of Leaf kept in the dark (non - photosynthesizing leaf) Shade of leaf: Shade of leaf: Analysis: 1. What does Lugol s iodine test for? 2. Describe similarities in the two leaves after they have been boiled and stained with Lugol s iodine solution. 3. Describe the differences in the two leaves after they have been boiled and stained with Lugol s iodine solution. 4. Which leaf contains the most starch, the one that had been covered or the one that was not covered? Explain your answer using evidence from the lab. 5. In this experiment, what is the purpose of removing, boiling and staining both a leaf that was kept in the light and a leaf that was kept in the dark? 11
Conclusion: 1. Did the Calvin cycle take place in the cells located in the leaf that was covered and kept in the dark? How do you know? 2. Photosynthesis produces glucose. Lugol s iodine solution tests for starch. What is the relationship between starch and glucose? 3. Why is it important to primary consumers, like you, that plants store energy as starch? 4. Describe where the light-dependent reactions occur in the chloroplast. 5. Describe where the light-independent reactions (Calvin Cycle) occur in the chloroplast. 6. Describe how the Calvin cycle is dependent upon the events of the light-dependent reactions. 7. Write a chemical equation that describes the process of photosynthesis. 12
WORD BANK Light Light-dependent reaction Products Calvin Cycle Light Energy Reactants chloroplast H 20 CO 2 C 6H 120 6 0 2 13
Exploring Cellular Respiration Demo 1: Energy Release and Transfer 1. What materials are being used in this demo? a. b. c. 2. What is released during cellular respiration? 3. Temp of water before energy is released and transferred to water? 4. Temp after energy is released and transferred? 5. What does this increase in temperature in the water mean? Demo 2: Water Release 1. What is the equation for cellular respiration? 2. If we capture what is released from the respiration of the corn chip into the upside down beaker, what should be captured? 3. After burning the corn chip was can you see in the beaker? 4. What does the formation of this condensation mean? Demo 3: Carbon Dioxide Release 1. Other than water and energy, what is released during cellular respiration? 2. How long did each corn chip burn? In beaker: Not in beaker: 3. Why do you think they burned for different times? 14
Mitochondria Reading Activity Mitochondria are the powerhouses of the cell because they burn or break the chemical bonds of glucose to release energy to do work in a cell. Remember, this energy originally came from the sun and was stored in chemical bonds by plants during photosynthesis. Glucose and other carbohydrates made by plants during photosynthesis are broken down by the process of aerobic cellular respiration (requires oxygen) in the mitochondria of the cell. This releases energy (ATP) for the cell. The more active a cell (such as a muscle cell), the more mitochondria it will have. The mitochondria are about the size of a bacterial cell and are often peanutshaped. Mitochondria have their own DNA and a double membrane like the nucleus and chloroplast. The outer membrane is smooth, while the inner membrane is convoluted into folds called cristae in order to increase the surface area. Label the outer membrane and the cristae on figure 3. This greatly increases the surface area of the membrane so that carbohydrates (simple sugars) can combine with oxygen to produce ATP, adenosine triphosphate (the energy molecule of the cell). The electron transport chain takes place across the membranes of the cristae (crista, singular). Inside the folds or cristae is a space called the matrix that contains enzymes needed for the Kreb's Cycle. Label the matrix on figure 3. FIGURE 3 - MITOCHONDRIA Adenosine triphosphate (ATP) is the energy molecule used by all cells to do work. It is a nucleotide consisting of a nitrogen-containing base (adenine, thymine, cytosine, or guanine), a 5-carbon sugar, and 3 phosphate groups. ATP is able to store and transport chemical energy within cells. The LAST TWO phosphate groups (PO4), are joined by HIGH-ENERGY bonds. When these bonds are broken, energy is released for cells to use and ADP forms. Enzymes help to break and reform these high-energy bonds. ON THE BACK SIDE: In Figure 4, label the 5-carbon sugar RIBOSE. LABEL the nitrogen-base. LABEL the 3 phosphate groups, and LABEL the 2 high-energy bonds. 15
FIGURE 4 ATP MOLECULE Questions: 1. Why are mitochondria called the powerhouse of the cell? 2. How would the number of mitochondria in an insect's wing compare to the amount found in other cells in an insect's body? Explain your answer. 3. What product of photosynthesis is used in cellular respiration? 4. What cell process occurs in the mitochondria? 5. Why do some cells have MORE mitochondria? Give an example. 6. Name 2 other organelles besides the mitochondria that contain DNA & have a double membrane. & 7. What simple sugar is broken down in the mitochondria? 8. What does ATP stand for? 9. What three main things make up an ATP molecule? 10. When ATP loses a phosphate group is released for cells and a molecule of forms. 11. How many high-energy bonds does ATP contain? 16
Anaerobic Respiration Lab PART I PROCEDURE 1. Obtain one Ziploc bag. 2. Place one spoonful of yeast into the bag. Set aside. 3. Obtain 7-9 large grapes and test the ph of the grapes by squeezing the juice of one grape onto a ph strip. Record the ph of the grape juice in the data table. 4. Place all the grapes into the Ziploc bag and seal bag. 5. Using your fingers, GENTLY crush each grape to release the grape juice. Make sure the grape juice mixes with the dry yeast. 6. Open the bag and smell the juice in the bag by wafting. Record your observation in the data table. 7. Close the bag, making sure you squeeze out any air. Record your observations about the appearance of the bag in the data table. 8. Let the bag sit on your lab table at room temperature for about 35 minutes. 9. Record your observations about the appearance of the bag in the data table. 10. Open the bag. Allow some of the juice to touch the ph strip. Record the ph in the data table. 11. Smell the juice in the bag. Record your observation in the data table. DATA & OBSERVATIONS Initial Observations Observations after 35 minutes ph of grape juice Observation of smell Observation of appearance PART II PROCEDURE 1. One member of your team will be the timekeeper while the other member will do the exercising. 2. Rest your elbow on the table. Open and close your hand as rapidly and forcefully as you can, counting the number of times you can do this in 20 seconds. In the table provided, record the number of times you closed your hand. 3. Repeat step 2 nine more times and record the results of each trial in the table. 4. Reverse roles and repeat steps 2 and 3. 17
DATA & OBSERVATIONS Trial 1 2 3 4 5 6 7 8 9 10 Number of Closures Student 1 Student 2 Prepare a graph with the results. Plot the number of closures per trial versus the number of trials. Remember: Always put the independent variable on the x-axis. Which is the independent variable (number of trials or number of closures)? 18
DATA ANALYSIS 1. Which kind of respiration is occurring in the yeast cells? How do you know? is occurring in the yeast cells because 2. Which type of respiration is occurring in your muscle cells? Why does this occur? is occurring in our muscle cells because 3. What is present as a product in the Ziploc that might have caused the ph of the solution to change? 4. What are some commercial applications of this experiment? 19
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Photosynthesis & Cellular Respiration WORD BANK Energy H 20 CO 2 C 6H 120 6 0 2 Photosynthesis Sunlight H 20 CO 2 C 6H 120 6 0 2 Animal & Plant Cells Anaerobic Respiration Alcoholic Fermentation Yeast Lactic Acid Fermentation Bacteria & Muscle Cells 2 ATP Chloroplasts inside plant cells Aerobic Respiration Cellular Respiration 36 ATP Unit 8 Vocabulary Energy Conversion in Cells 1. Aerobic process that requires oxygen to occur 2. Alcoholic Fermentation anaerobic process that breaks down sugars for energy when oxygen isn t present; produces alcohol; occurs in yeast 3. Anaerobic process that does not require oxygen to occur 4. ATP (Adenosine Triphosphate) high-energy molecule that contains, within its bonds, energy that cells can use 5. Calvin Cycle process by which a photosynthetic organism uses energy to synthesize simple sugars from CO 2 6. Cellular Respiration process of producing ATP by breaking down carbon-based molecules when oxygen is present 7. Chemical Equation symbolic representation showing the kind and amount of the starting materials and products of a reaction. 8. Chlorophyll light-absorbing pigment molecules in photosynthetic organisms 9. Chloroplast organelle composed of numerous membranes that are used to convert solar energy into chemical energy; contains chlorophyll 10. Cristae inner membrane of the mitochondrion where the electron transport chain occurs 11. Electron Transport Chain series of proteins in the thylakoid and mitochondrial membranes that aid in converting ADP to ATP by transferring electrons 12. Glucose - high energy sugar formed in photosynthesis & broken down in cellular respiration to produce energy for cells 13. Glycolysis anaerobic process in which glucose is broken down into two molecules of pyruvate and two net ATP are produced 14. Grana stack of thylakoid membranes in chloroplasts 15. Kreb s Cycle process during cellular respiration that breaks down a carbon molecule to produce molecules that are used in the electron transport chain 16. Lactic Acid Fermentation anaerobic process that breaks down sugars for energy when oxygen is not present; produces lactic acid; occurs in muscle cells and bacteria 17. Matrix inner space of the mitochondria where the Kreb s Cycle occurs 18. Membrane thin layer surrounding a cell or a cell part that regulates what enters or exits the cell or cell part or in which chemical reactions occur 19. Mitochondria bean-shaped organelle that supplies energy to the cell and has its own ribosomes & DNA 20. Photosynthesis process by which light energy is converted to chemical energy; produces sugar and oxygen from carbon dioxide and water 21. Products substance formed in a chemical reaction 22. Reactants substance that is changed by a chemical reaction 23. Stomata pores in the cuticle of a plant through which gas exchange occurs 24. Stroma region outside the thylakoid membranes in chloroplast; site of Calvin Cycle 25. Thylakoid saclike photosynthetic membranes found in chloroplasts; site of Light-dependent reactions 21