Bio07_TR_U03_CH08.QXD 4/25/06 2:51 PM Page 63 Name Class Date Chapter 8 Photosynthesis Section 8 1 Energy and Life (pages 201 203) Key Concepts Where do plants get the energy they need to produce food? What is the role of ATPin cellular activities? Autotrophs and Heterotrophs (page 201) 1. Where does the energy of food originally come from? 2. Complete the table describing the types of organisms. TYPES OF ORGANISMS Type Description Examples Organisms that make their own food Organisms that obtain energy from the food they eat Chemical Energy and ATP (page 202) 3. What is one of the principal chemical compounds that cells use to store energy? 4. How is ATP different from ADP? 5. Label each part of the ATP molecule illustrated below. P P P 6. When a cell has energy available, how can it store small amounts of that energy? 63
Bio07_TR_U03_CH08.QXD 4/25/06 2:51 PM Page 64 Name Class Date 7. When is the energy stored in ATP released? 8. For what purpose do the characteristics of ATP make it exceptionally useful to all types of cells? 9. What are two ways in which cells use the energy provided by ATP? a. b. Using Biochemical Energy (pages 202 203) 10. Why is it efficient for cells to keep only a small supply of ATP on hand? 11. Circle the letter of where cells get the energy to regenerate ATP. a. ADP b. phosphates c. foods like glucose d. organelles 64
Bio07_TR_U03_CH08.QXD 4/25/06 2:51 PM Page 65 Name Class Date Section 8 2 Photosynthesis: An Overview (pages 204 207) Key Concepts What did the experiments of van Helmont, Priestley, and Ingenhousz reveal about how plants grow? What is the overall equation for photosynthesis? What is the role of light and chlorophyll in photosynthesis? Introduction (page 204) 1. What occurs in the process of photosynthesis? Investigating Photosynthesis (pages 204 206) 2. What did Jan van Helmont conclude from his experiment? 3. Circle the letter of the substance produced by the mint plant in Joseph Priestley s experiment. a. carbon dioxide b. water c. air d. oxygen 4. What did Jan Ingenhousz show? The Photosynthesis Equation (page 206) 5. Write the overall equation for photosynthesis using words. 6. Photosynthesis uses the energy of sunlight to convert water and carbon dioxide into oxygen and high-energy. Light and Pigments (page 207) 7. What does photosynthesis require in addition to water and carbon dioxide? 65
Bio07_TR_U03_CH08.QXD 4/25/06 2:51 PM Page 66 Name Class Date 8. Plants gather the sun s energy with light-absorbing molecules called. 9. What is the principal pigment of plants? 10. Circle the letters of the regions of the visible spectrum in which chlorophyll absorbs light very well. a. blue-violet region b. green region c. red region d. yellow region Reading Skill Practice By looking at illustrations in textbooks, you can help yourself remember better what you have read. Look carefully at Figure 8 4 on page 206. What important ideas does this illustration communicate? Do your work on a separate sheet of paper. 66
Bio07_TR_U03_CH08.QXD 4/25/06 2:51 PM Page 67 Name Class Date Section 8 3 The Reactions of Photosynthesis (pages 208 214) Key Concepts What happens in the light-dependent reactions? What is the Calvin cycle? Inside a Chloroplast (page 208) 1. Chloroplasts contain saclike photosynthetic membranes called. 2. What is a granum? 3. The region outside the thylakoid membranes in the chloroplasts is called the. 4. What are the two stages of photosynthesis called? a. b. 5. Complete the illustration of the overview of photosynthesis by writing the products and the reactants of the process, as well as the energy source that excites the electrons. Chloroplast NADP + ADP + P Light- Dependent Reactions Calvin Cycle ATP NADPH 67
Bio07_TR_U03_CH08.QXD 4/25/06 2:51 PM Page 68 Name Class Date Electron Carriers (page 209) 6. When sunlight excites electrons in chlorophyll, how do the electrons change? 7. What is a carrier molecule? 8. Circle the letter of the carrier molecule involved in photosynthesis. a. H 2 O c. CO 2 b. NADP + d. O 2 9. How does NADP + become NADPH? Light-Dependent Reactions (pages 210 211) 10. Circle the letter of each sentence that is true about the light-dependent reactions. a. They convert ADP into ATP. b. They produce oxygen gas. c. They convert oxygen into carbon dioxide. d. They convert NADP + into NADPH. 11. Where do the light-dependent reactions take place? 12. Circle the letter of each sentence that is true about the light-dependent reactions. a. High-energy electrons move through the electron transport chain from photosystem II to photosystem I. b. Photosynthesis begins when pigments in photosystem I absorb light. c. The difference in charges across the thylakoid membrane provides the energy to make ATP. d. Pigments in photosystem I use energy from light to reenergize electrons. 13. How does ATP synthase produce ATP? 68
Bio07_TR_U03_CH08.QXD 4/25/06 2:51 PM Page 69 Name Class Date The Calvin Cycle (pages 212 214) 14. What does the Calvin cycle use to produce high-energy sugars? 15. Why are the reactions of the Calvin cycle also called the light-independent reactions? 16. Circle the letter of each statement that is true about the Calvin cycle. a. The main products of the Calvin cycle are six carbon dioxide molecules. b. Carbon dioxide molecules enter the Calvin cycle from the atmosphere. c. Energy from ATP and high-energy electrons from NADPH are used to convert 3-carbon molecules into higher-energy forms. d. The Calvin cycle uses six molecules of carbon dioxide to produce a single 6-carbon sugar molecule. Factors Affecting Photosynthesis (page 214) 17. What are three factors that affect the rate at which photosynthesis occurs? a. b. c. 18. Is the following sentence true or false? Increasing the intensity of light decreases the rate of photosynthesis. 69
Name Class Date Chapter 9 Cellular Respiration Section 9 1 Chemical Pathways (pages 221 225) Key Concepts What is cellular respiration? What happens during the process of glycolysis? What are the two main types of fermentation? Chemical Energy and Food (page 221) 1. What is a calorie? 2. How many calories make up 1 Calorie? 3. Cellular respiration begins with a pathway called. 4. Is the following sentence true or false? Glycolysis releases a great amount of energy. Overview of Cellular Respiration (page 222) 5. What is cellular respiration? 6. What is the equation for cellular respiration, using chemical formulas? 7. Label the three main stages of cellular respiration on the illustration of the complete process. Electrons carried in NADH Pyruvic acid Electrons carried in NADH and FADH 2 Glucose Cytoplasm Mitochondrion ATP ATP ATP 101
Name Class Date 8. What would be the problem if cellular respiration took place in just one step? 9. Where does glycolysis take place? 10. Where do the Krebs cycle and electron transport take place? Glycolysis (page 223) 11. What is glycolysis? 12. How does the cell get glycolysis going? 13. If the cell uses 2 ATP molecules at the beginning of glycolysis, how does it end up with a net gain of 2 ATP molecules? 14. What is NAD +? 15. What is the function of NAD + in glycolysis? 16. Why can glycolysis supply energy to cells when oxygen is not available? 17. What problem does a cell have when it generates large amounts of ATP from glycolysis? 102
Name Class Date Fermentation (pages 224 225) 18. What is fermentation? 19. How does fermentation allow glycolysis to continue? 20. Because fermentation does not require oxygen, it is said to be. 21. What are the two main types of fermentation? a. b. 22. What organisms use alcoholic fermentation? 23. What is the equation for alcoholic fermentation after glycolysis? 24. What happens to the small amount of alcohol produced in alcoholic fermentation during the baking of bread? 25. What does lactic acid fermentation convert into lactic acid? 26. What is the equation for lactic acid fermentation after glycolysis? 27. During rapid exercise, how do your muscle cells produce ATP? Reading Skill Practice When you read about complex topics, writing an outline can help you organize and understand the material. Outline Section 9 1 by using the headings and subheadings as topics and subtopics and then writing the most important details under each topic. Do your work on a separate sheet of paper. 103
Name Class Date Section 9 2 The Krebs Cycle and Electron Transport (pages 226 232) Key Concepts What happens during the Krebs cycle? How are high-energy electrons used by the electron transport chain? Introduction (page 226) 1. At the end of glycolysis, how much of the chemical energy in glucose is still unused? 2. Because the final stages of cellular respiration require oxygen, they are said to be. The Krebs Cycle (pages 226 227) 3. In the presence of oxygen, how is the pyruvic acid produced in glycolysis used? 4. What happens to pyruvic acid during the Krebs cycle? 5. Why is the Krebs cycle also known as the citric acid cycle? 6. When does the Krebs cycle begin? 7. What happens to each of the 3 carbon atoms in pyruvic acid when it is broken down? 8. What happens to the carbon dioxide produced in breaking down pyruvic acid? 9. How is citric acid produced? 10. During the energy extraction part of the Krebs cycle, how many molecules of CO 2 are released? 11. What is the energy tally from 1 molecule of pyruvic acid during the Krebs cycle? 104
Name Class Date 12. When electrons join NAD + and FAD during the Krebs cycle, what do they form? 13. Why is the 4-carbon compound generated in the breakdown of citric acid the only permanent compound in the Krebs cycle? Electron Transport (pages 228 229) 14. What is the electron transport chain? 15. What does the electron transport chain use the high-energy electrons from the Krebs cycle for? 16. How does the location of the electron transport chain differ in eukaryotes and prokaryotes? 17. Where does the electron transport chain get the high-energy electrons that are passed down the chain? 18. Is the following sentence true or false? Hydrogen serves as the final electron acceptor of the electron transport chain. 19. What is the energy of the high-energy electrons used for every time 2 high-energy electrons move down the electron transport chain? 20. What causes the H + ions in the intermembrane space to move through the channels in the membrane and out into the matrix? 21. On average, how many ATP molecules are produced as each pair of high-energy electrons moves down the electron transport chain? 105
Name Class Date 22. Complete the flowchart about electron transport. (Review Figure 9 7 on page 228 of your textbook.) High-energy electrons from NADH and FADH 2 are passed into and along the. The energy from the electrons moving down the chain is used to move H + ions across the. H + ions build up in the space, making it charged and making the matrix negatively charged. H + ions move through channels of in the inner membrane. The ATP synthase uses the energy from the moving ions to combine ADP and phosphate, forming high-energy. The Totals (page 229) 23. How many ATP molecules are formed during cellular respiration? 24. Why is more ATP generated from glucose in the presence of oxygen? 25. What happens to the energy of glucose that is not used to make ATP molecules? 26. What are the final waste products of cellular respiration? 106
Name Class Date Energy and Exercise (pages 230 231) 27. What are three sources of ATP a human body uses at the beginning of a race? 28. When a runner needs quick energy for a short race, what source can supply enough ATP for about 90 seconds? 29. Why does a sprinter have an oxygen debt to repay after the race is over? 30. A runner needs more energy for a longer race. How does the body generate the necessary ATP? 31. Why are aerobic forms of exercise so beneficial for weight control? Comparing Photosynthesis and Cellular Respiration (page 232) 32. If photosynthesis is the process that deposits energy in a savings account, then what is cellular respiration? 33. How are photosynthesis and cellular respiration opposite in terms of carbon dioxide? 34. How are photosynthesis and cellular respiration opposite in terms of oxygen? 107