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1 Learning Targets & Focus Questions for Unit 6: Bioenergetics Chapter 8: Thermodynamics Chapter 9: Cell Resp Focus Q Ch. 10: Photosynthesis Chapter 8 ( ) 1. I can explain how living systems adhere to the first and second laws of thermodynamics. 2. I can explain how living systems apparently defy the second law of thermodynamics by increasing in order (decreasing their entropy). 3. I can explain how the following equation relates to free energy, and is used to differentiate between exergonic and endergonic reactions: G = H - TS. 4. I can explain how ATP powers cellular work by coupling exergonic and endergonic reactions. Focus Questions: 1. State the first law of thermodynamics and explain how living systems comply with this law. Provide one real-life example to support your explanation. 2. State the second law of thermodynamics and explain how living systems comply with this law. Provide one real-life example to support your explanation. 3. How is the maintenance of a highly ordered living system possible, given the tendency of the Universe to tend toward increasing disorder? Provide an explanation for the order of an organism, AND an explanation for the order of successive generations of organisms. 4. Is a living system ever in equilibrium with its surroundings? Explain why or why not, and when equilibrium occurs (if ever). 5. Explain the energetic advantage of coupling exergonic reactions to endergonic reactions. Which reaction must be greater in terms of energetic magnitude? 6. Organisms are endergonic systems. What are the exergonic reactions that provide living systems with energy (give two examples). Be sure to understand: The relationships between the following pairs of words: Metabolism, Anabolic and Catabolic Exergonic and Endergonic Energy and Free Energy Free energy and Equilibrium Open and closed system The energetic relationship between an organism and it s surroundings. Why organisms need to release energy in a series of controlled steps The structure of an ATP molecule. How an ATP molecule is converted into an ADP molecule and how that process produces energy. Why we can t consume ATP directly. Why living systems need to take in more energy than they put out into the environment.

2 Chapter 9: Cellular Respiration: 1. I can explain how catabolic pathways yield energy by oxidizing organic fuels. a. I can write the summary equation for cellular respiration. b. I can define oxidation and reduction, and identify what is oxidized and what is reduced in cellular respiration. c. I can describe the role of NAD+ in cellular respiration. d. I can name the three stages of cellular respiration and state the region of the eukaryotic cell where each stage occurs. 2. I can explain how glycolysis harvests chemical energy by oxidizing glucose to pyruvate. a. I can list the reactants and products of glycolysis, and describe how the carbon skeleton of glucose changes during this process. b. I can specifically describe where glycolysis is occurring in a cell. c. I can Identify the oxidizing agent of glycolysis. d. I can state how many ATP s are generated from glycolysis and explain how these ATP s are generated. e. I can state how many NADH s are generated from glycolysis 3. I can explain how the citric acid (Krebs) cycle completes the energy yielding oxidation of organic molecules. a. I can describe where pyruvate is oxidized to acetyl CoA, what molecules are produced, and how this process links glycolysis to the citric acid cycle. b. I can list the products of the citric acid cycle and explain why it is called a cycle. c. I can identify the oxidizing agent of the citric acid cycle. d. I can state how many ATP s are generated from the pyruvate à citric acid cycle stage of cellular respiration, and explain how they are generated. e. I can state how many NADH and FADH2 molecules are generated from the pyruvate à citric acid cycle stage of cellular respiration. f. I can specifically describe where the pyruvate à citric acid cycle stage of cellular respiration is occurring in a cell 4. I can explain how oxidative phosphorylation couples electron transport to ATP synthesis. a. I can describe the free energy change during electron transport. b. I can specifically describe where oxidative phosphorylation is occurring within a cell. c. I can explain where the energy for the active transport of hydrogen ions comes from. d. I can describe the energy transformations that occur from the time that NADH is oxidized to ATP production. e. I can state the number of ATP s that are generated from the oxidation of 1 NADH and from 1 FADH2 via oxidative phosphorylation. f. I can determine how ATP s are generated from oxidative phosphorylation when beginning with the oxidation of 1 glucose molecule. g. I can determine how many ATP s would be generated by starting with any molecule in cellular respiration, such as glucose, acetyl CoA etc h. I can explain why mitochondrial processes shut down in the absence of oxygen. 5. I can explain how fermentation and anaerobic respiration allow cells to produce ATP without the use of oxygen. a. I can explain how glycolysis can continue in the absence of oxygen. b. I can explain why pyruvate is a key juncture in cellular respiration. c. I can distinguish between alcohol fermentation and lactic acid fermentation and describe which organisms perform which reactions.

3 d. I can describe when and where fermentation is used in a cell. 6. I can show how glycolysis and the citric acid cycle connect to many other metabolic pathways a. I can describe how food molecules other than glucose can be oxidized to make ATP s. b. I can explain how ATP production is regulated by the cell and describe the role that allosteric enzymes such as phosphofructokinase plays in the process. Focus Questions: Aerobic Respiration 1. Why are pyruvate converted into acetyl-coa prior to entering the Kreb s cycle? What does this conversion do to the pyruvate molecules? 2. Oxygen is not used in the Kreb s cycle, so why must the Kreb s cycle occur in aerobic cellular respiration? 3. Where in the mitochondria does oxidative phosphorylation occur? Why does it occur there? 4. What products of the prior phases of cellular respiration are used in the electron transport chain? How are they used? 5. Diagram the movement of an electron through the electron transport chain in a mitochondrion. Include its source, destination, and all products made directly and indirectly. a. Compare and contrast the processes of chemiosmosis in aerobic cellular respiration and photosynthesis. 6. How much more energy is produced by aerobic cellular respiration than by anaerobic cellular respiration? 7. Estimate the efficiency of aerobic cellular respiration of a molecule of glucose: i. Energy of formation of ATP from ADP: ~ + 57 KJ/Mol ii. Energy of combustion of glucose: ~ KJ/Mol 8. Compare and contrast the metabolism of glucose with the metabolism of complex carbohydrates, Proteins & Fats. Explain where each molecule (or component of the molecule) enters the aerobic cellular respiration pathway, and order each in terms of the amount of energy they produce for the cell. 9. Explain the effect of each of the following substances on phophofructokinase, and the overall effect they have on cellular respiration, and the system logic of each effect: a. AMP b. Citrate c. ATP 1. The starting materials, end products, and eventual fates of all of the molecules used and produced in the acetylcoa cycle, the Kreb s cycle and oxidative phosphorylation. 2. The relationship between the evolution of photosynthesis, the evolution of oxidative phosphorylation, and the evolution of multi-cellular life. 3. The meaning of the term proton-motive force. 4. The relationship between the catabolic pathways of cellular respiration and the anabolic pathways of biosynthesis. Focus Questions: Anaerobic Respiration 1. What is the relationship between photosynthesis and aerobic cellular respiration? 2. In cellular respiration, what is oxidized and what is reduced? 3. What is the role of electron carrier molecules in energy processing systems? Why are they necessary? 4. Is glucose the only molecule that can be catabolized during cellular respiration? Why do we use glucose as the model? 5. Why do hydrogen atoms accompany electrons as they are transferred in biological systems? 6. Why is it thought that glycolysis is the first catabolic pathway to have evolved in the metabolism of all cellular systems?

4 7. Can a cell produce enough ATP to persist by using glycolysis alone? Why or why not? 8. Why do anaerobic cellular systems use fermentation? What would happen if they didn t? 9. Why do mammalian muscle cells perform lactic acid fermentation (instead of, say, ethanol fermentation)? 1. The energy processing strategies of each of the following modes of nutrition, and example organisms that engage in each mode: a. Heterotrophs b. Photosynthetic Autotrophs c. Chemosynthetic Autotrophs 2. Why food molecules need to be broken down into smaller molecules for energy to be harvested from them. 3. The molecule that is oxidized and the molecule that is reduced in any REDOX reaction. 4. The starting materials, end products and eventual fates of all of the molecules used and produced in glycolysis, lactic acid fermentation and ethanol fermentation. Chapter 10 Photosynthesis 1. I can describe how photosynthesis converts light energy to the chemical energy of food. a. I can distinguish between autotrophic and heterotrophic nutrition. b. I can describe the structure of a chloroplast, listing all membranes and compartments, and I can identify and label where each part of photosynthesis occurs. c. I can write the summary equation for photosynthesis. d. I can explain the role of redox reactions in photosynthesis. e. I can describe the two main stages of photosynthesis. f. I can identify all of the plant structures that are involved in brining reactants of photosynthesis to the chloroplasts and the structures involved in releasing products from the plant 2. I can explain how the light reactions work to convert solar energy to the chemical energy of ATP and NADPH a. I can describe the relationship between an action spectrum and an absorption spectrum. Explain why the action spectrum for photosynthesis differs from the absorption spectrum for chlorophyll a. b. I can list the wavelengths of light that are most effective for photosynthesis. c. I can describe the effect that absorption and reflection of light by pigments, has on the colors we see, and photosynthetic activity. d. I can describe what a photosystem looks like, where it is located and how it harvests light. e. I can explain what pigment is found in the reaction center of the photosystem. f. I can list the reactants and the products of the light reaction. g. I can explain where input items come from and where output products go in the light reactions. h. I can trace the movement of electrons in both cyclic and non-cyclic electron flow. i. I can explain the functions of cyclic and non-cyclic electron flow. j. I can describe the similarities and differences between the chemiosmosis of oxidative phosphorylation in mitohondria and photophsophorylation in chloroplasts. 3. I can describe how the calvin cycle uses ATP and NADPH to convert carbon dioxide to sugar. a. I can state the function of each of the three phases of the Calvin cycle. b. I can describe the role of ATP and NADPH in the Calvin cycle. Focus Questions (Light Reactions): 1. Explain the relationship between the light reactions and the Calvin cycle in photoautotrophs. 2. What is the function of the Magnesium atom in a chlorophyll molecule?

5 3. Where do replacement electrons come from in photosystem II? 4. Diagram the flow of an electron from photosystem II to eventually winding up in a molecule of NADPH. 5. Explain how ATP is produced in photosynthesis. 6. Why are plants green in color? 7. Compare and contrast cyclic and non-cyclic photophosphorylation. Include the products of each and the fates of those products. 8. Why is water necessary for photosynthesis? 9. Why is oxygen produced during the light reactions? Focus Questions: Calvin Cycle 1. What happens during the Calvin cycle? How does the Calvin cycle depend on the Light reactions? 2. Explain the function of Ribulose BisPhosphate Carboxylase (aka Rubisco) in the Calvin Cycle. 3. What is G3P? 4. Looking at the net equation for photosynthesis of one molecule of glucose, what molecules are oxidized, and what molecules are reduced? 5. Why do plants need to control the loss of water? How is this done? 6. Explain the phenomenon of photorespiration, why it is thought to occur (evolutionarily speaking), and why plants have evolved to minimize its occurrence. 7. Why are C4 and CAM plants typically found in hot climates? The starting materials, end products and eventual fates of all of the molecules used and produced in the light reactions of photosynthesis The starting materials, end products and eventual fates of all of the molecules used and produced in the Calvin cycle of photosynthesis. The adaptations of C4 and CAM plant photosynthesis and how each is able to minimize photorespiration.