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 Unit 8 KUDs 5-6 The Great Energy Caper 7-8 Starch Production in Photosynthesis Lab 9-12 Photosynthesis Notes 13-16 Photosynthesis Flow Chart 17 Exploring Cellular Respiration Demos 18-19 Aerobic Respiration Notes 20-22 Mitochondria Reading Activity 23-24 Anaerobic Respiration Notes 25-26 Anaerobic Respiration Lab 27-29 Energy Conversions Flow Chart 30 Unit 8 Vocabulary 31 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
Unit 8: Energy Conversions in Cells What should I understand, know and be able to do? By the end of the unit I will UNDERSTAND that Got it Energy conversions support the cycling of matter in an ecosystem. By the end of the unit I will KNOW that The conversion of ADP to ATP is the means by which cells store and transfer energy. (9B) Photosynthesis the process by which light energy is converted to chemical energy (glucose). Glucose molecules bond together to form starch, a common storage molecule in plants. Photosynthesis occurs in the chloroplast of a plant and includes both light-dependent reactions and light-independent reactions (dark reactions or the Calvin cycle). Light energy is absorbed by chlorophyll in the thylakoid of the chloroplast. During the light-dependent reactions of photosynthesis, energy is absorbed from sunlight and transferred to ATP, water molecules are broken down and oxygen is released. During the light-independent reactions (dark reactions or Calvin cycle) of photosynthesis, ATP from the light-dependent reactions is used to build glucose (six carbon sugar) from carbon dioxide. The rate of photosynthesis is related to the number of stomata. The stomata are responsible for gas exchange (CO 2, O 2 and H 2 O) in the plant. Cellular respiration is the process by which chemical energy (glucose) is converted to usable energy by the cell (ATP). Both plants and animals perform cellular respiration. Aerobic respiration occurs in the presence of oxygen; anaerobic occurs in its absence. Glycolysis occurs in the cytoplasm and is required for both aerobic and anaerobic respiration. Glycolysis breaks glucose (six carbon sugar) into pyruvate (three carbon sugar) to generate ATP. Cellular respiration (the Kreb s cycle or the Citric Acid Cycle and the electron transport chain) occur in the mitochondria in the presence of oxygen. During the Kreb s cycle (Citric Acid Cycle) and the electron transport chain, pyruvate (three carbon sugar) is broken down to release carbon dioxide, oxygen is used to make water molecules and a large number of ATP is generated. Aerobic respiration produces more ATP compared to anaerobic respiration. There are two types of anaerobic respiration: lactic acid fermentation and alcohol fermentation. The energy stored in the chemical bonds of ATP is used by cells to do work. At the conclusion of photosynthesis, energy is stored in the chemical bonds of glucose, a six carbon sugar. (4B) The reactants (water, carbon dioxide and light energy) and products (glucose and oxygen) of photosynthesis. The balanced equation for photosynthesis shows that six molecules of carbon dioxide and six molecules of water are required to produce one molecule of glucose. At the conclusion of cellular respiration, energy is stored in the chemical bonds of ATP. (4B) Cellular respiration is the inverse reaction of photosynthesis. 5
The reactants (carbohydrates/glucose and oxygen) and products (water, carbon dioxide and energy/atp) of cellular respiration. By the end of the unit I will BE ABLE TO Label a chloroplast to indicate where the reactions of photosynthesis occur. (9B) Label the mitochondria to indicate where cellular respiration occurs. Given a scenario trace the flow of energy through photosynthesis and respiration. Identify the reactants and products of photosynthesis. Write the balanced chemical equation that represents photosynthesis. Differentiate between the light-dependent and light-independent reactions of photosynthesis. Explain the link between the light-dependent and light-independent reactions to the overall process of photosynthesis. Identify the reactants and products of cellular respiration. Write the balanced chemical equation that represents cellular respiration. Compare the products of anaerobic respiration to the products of aerobic respiration in terms of energy produced. Analyze the relationship between photosynthesis and respiration. (4B) 6
The Great Energy Caper Topic: Using complete sentences, describe your ideal (perfect) burger with at least 4 ingredients. Be sure to include all the ingredients you like on your burger. Explain the energy flow of the ingredients in your burger. 7
The Great Energy Caper Topic: Draw 4 flow charts that trace the energy flow of 4 of the ingredients in your burger. Answer the following questions: What is the origin of the energy for all the ingredients? How do plants transfer light energy from the sun to herbivores? How do herbivores use the energy they obtain from eating plants? Example - Ingredient: French Fries Ingredient 1: Flow Chart: Ingredient 2: Flow Chart: Ingredient 3: Flow Chart: Ingredient 4: Flow Chart: 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. Energy 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 Kept in the Dark (non-photosynthesizing leaf) Diagram of Leaf Exposed to Light (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
Photosynthesis Notes Starch is produced in the leaves of plants. What process produces starch in plants? Where in the leaf does photosynthesis occur? Observing Stomata Leaf 1 Leaf 2 Leaf 3 Name of Leaf Cactus live in hot, dry environment Oak Tree Hibiscus live in warm, tropical environments Observations Drawing Observing Stomata Discussion Questions Which leaf had the most stomata? Why do you think this was so? What gases move in and out of the leaf stomata? What does the number of stomata indicate about the rate of photosynthesis for a plant? 13
PHOTOSYNTHESIS OCCURS IN THE CHLOROPLAST Draw the process of photosynthesis below. are specialized organelles to carry out photosynthesis! 14
Use your diagram to write the chemical equation of photosynthesis. How do CO 2 and H 2 O get converted into sugar? Where? We said that plants need energy from the sun. How does it get energy? is absorbed by the pigments in the thylakoid of the chloroplast. The energy absorbed will split into and during the light-dependent reactions. The next set of reactions occurs in the. These are light-independent reactions. Three main stages to photosynthesis Stage 1 Stage 2 is converted to, which is temporarily stored in and energy carrier molecule NADPH Stage 3 The chemical energy stored in ATP and NADPH powers the formation of (i.e. sugar), using carbon dioxide (CO 2 ) 15
How many molecules of carbon dioxide does it take to make one molecule of glucose? Where is the energy stored? What are the products of photosynthesis? Where does the oxygen come from? Summary: STAGE What happens during this stage? Where in the chloroplast does it happen? What is produced in this stage? Stage 1 Stage 2 Stage 3 Chemical Equation for Photosynthesis 16
WORD BANK Light Light-dependent reaction Products Calvin Cycle Light Energy Reactants chloroplast H 2 0 CO 2 C 6 H 12 0 6 0 2 17
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? 18
Write a 5 sentence summary explaining what you know about cellular respiration after observing these demonstrations? 19
AEROBIC Cellular Respiration Notes What did we learn in yesterday s lab? Sugar (carbohydrates) were broken down Oxygen must be present Carbon dioxide was released Water was released What process breaks down sugars? Let s look at the process of cellular respiration in general. Label the diagram below using the ppt. Use your diagram to write the chemical equation for Aerobic cellular Respiration. Reactants What goes Products What is + + + energy How do the Carbohydrates break down? Where? Just as photosynthesis uses the structure of the chloroplast to facilitate the process, uses the structure of an organelle called the. 20
Label the following diagram using the ppt notes. How does glucose enter the cell? A process called breaks the 6 carbon glucose into two 3 carbon. What is produced? THE PYRUVATES ENTER THE KREB S CYCLE IN THE MITOCHONDRIA (A.K.A. ) What is produced? ELECTRON TRANSPORT CHAIN ACROSS INNER MEMBRANES OF MITOCHONDRIA. What is produced 21
WHAT IS ATP??? ATP (adenosine triphosphate) a with two extra - phosphate groups. + + + o How cells release energy from ATP: By releasing a phosphate group, the energy stored between the two can now be released. SUMMARY: Stages of Aerobic Cellular Respiration There are 3 stages in aerobic cellular respiration: Glycolysis - Kreb s cycle (aka Citric Acid Cycle) Electron transport chain- According to the equation, what is the energy source? Where does the carbon dioxide come from? How many molecules of water are created? The oxygen on the reactant side forms which molecule on the product side? Stage of cellular respiration Where is the process happening? What is going into the stage? What is being produced in this stage? Glycolysis Krebs Cycle Electron Transport Chain Chemical Equation for Cellular Respiration 22
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 peanut-shaped. 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. 23
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? 24
Anaerobic Respiration Background Info & Notes BACKGROUND INFORMATION Read for Warm Up! The process of fermentation is a component of anaerobic respiration, which is when respiration takes place in the absence of oxygen. In yeast cells, when this process occurs, it is called alcoholic fermentation. The products of this type of respiration are carbon dioxide and ethyl alcohol, as shown below: C 6 H 12 O 6 2C 2 H 6 O 2 + 2CO 2 This process is of particular interest to humans, since it is the source of the alcohol in wine and beer. This particular process only produces about 12% alcohol, which is enough to destroy the yeast cells, which are producing the alcohol. Upon conclusion of anaerobic respiration, if the products of this process are exposed to air, Acetobacter bacteria present in the air will convert the ethyl alcohol into acetic acid. This is why wine that has been in a cellar for a very long time will not taste like wine, but rather like vinegar. This process occurs in animal cells as well, but of course, animals do not produce ethyl alcohol. Instead, a process known as lactic acid fermentation takes place, and lactic acid rather than ethyl alcohol is produced. As a result of this kind of fermentation, muscle cramps and soreness occur due to the buildup of lactic acid in the muscle cells. NOTES: ANAEROBIC RESPIRATION In the anaerobic cellular respiration labs we completed, what conditions were different from aerobic cellular respiration? Anaerobic Cellular Respiration What happens when there is not enough oxygen for aerobic respiration to occur? A) B) What is the name of this process? Fermentation (aka Anaerobic Cellular Respiration): An anaerobic process needed to continue making ATP through glycolysis. 2 types of fermentation 25
Lactic Acid Fermentation Organisms that go through this process: How we make buttermilk Ever felt sore after an intense workout? Where in the cell does this process take place? How much energy do you create? What is your energy source? Is this process aerobic or anaerobic? Alcoholic Fermentation Organisms that go through this process: Can you think of a process in which we use yeast? Where in the cell does this process take place? How much energy do you create? What is your energy source? Is this process aerobic or anaerobic? 26
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. 27
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)? 28
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 ziplock that might have caused the ph of the solution to change? 4. What are some commercial applications of this experiment? 29
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Photosynthesis & Cellular Respiration WORD BANK Energy H 2 0 CO 2 C 6 H 12 0 6 0 2 Photosynthesis Sunlight H 2 0 CO 2 C 6 H 12 0 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 carbonbased 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 31