Table of Contents – pages iv-v Unit 1: What is Biology? Unit 2: Ecology Unit 3: The Life of a CellThe Life of a Cell Unit 4: Genetics Unit 5: Change Through Time Unit 6: Viruses, Bacteria, Protists, and Fungi Unit 7: Plants Unit 8: Invertebrates Unit 9: Vertebrates Unit 10: The Human Body
Table of Contents – pages iv-v Unit 1: What is Biology? Chapter 1: Biology: The Study of Life Unit 2: Ecology Chapter 2: Principles of Ecology Chapter 3: Communities and Biomes Chapter 4: Population Biology Chapter 5: Biological Diversity and Conservation Unit 3: The Life of a CellThe Life of a Cell Chapter 6: The Chemistry of Life Chapter 7: A View of the Cell Chapter 8: Cellular Transport and the Cell Cycle Chapter 9: Energy in a CellEnergy in a Cell
Table of Contents – pages iv-v Unit 4: Genetics Chapter 10: Mendel and Meiosis Chapter 11: DNA and Genes Chapter 12: Patterns of Heredity and Human Genetics Chapter 13: Genetic Technology Unit 5: Change Through Time Chapter 14: The History of Life Chapter 15: The Theory of Evolution Chapter 16: Primate Evolution Chapter 17: Organizing Lifes Diversity
Table of Contents – pages iv-v Unit 6: Viruses, Bacteria, Protists, and Fungi Chapter 18: Viruses and Bacteria Chapter 19: Protists Chapter 20: Fungi Unit 7: Plants Chapter 21: What Is a Plant? Chapter 22: The Diversity of Plants Chapter 23: Plant Structure and Function Chapter 24: Reproduction in Plants
Table of Contents – pages iv-v Unit 8: Invertebrates Chapter 25: What Is an Animal? Chapter 26: Sponges, Cnidarians, Flatworms, and Roundworms Chapter 27: Mollusks and Segmented Worms Chapter 28: Arthropods Chapter 29: Echinoderms and Invertebrate Chordates
Table of Contents – pages iv-v Unit 9: Vertebrates Chapter 30: Fishes and Amphibians Chapter 31: Reptiles and Birds Chapter 32: Mammals Chapter 33: Animal Behavior Unit 10: The Human Body Chapter 34: Protection, Support, and Locomotion Chapter 35: The Digestive and Endocrine Systems Chapter 36: The Nervous System Chapter 37: Respiration, Circulation, and Excretion Chapter 38: Reproduction and Development Chapter 39: Immunity from Disease
Unit Overview – pages 138-139 The Life of a Cell The Chemistry of Life A View of the Cell Cellular Transport and the Cell Cycle Energy in a Cell
Chapter Contents – page viii Chapter 9 Energy in a Cell 9.1: The Need for EnergyThe Need for Energy 9.1: Section CheckSection Check 9.2: Photosynthesis: Trapping the Suns EnergyPhotosynthesis: Trapping the Suns Energy 9.2: Section CheckSection Check 9.3: Getting Energy to Make ATPGetting Energy to Make ATP 9.3: Section CheckSection Check Chapter 9 SummarySummary Chapter 9 AssessmentAssessment
Chapter Intro-page 220 What Youll Learn You will recognize why organisms need a constant supply of energy and where that energy comes from. You will identify how cells store and release energy as ATP. You will describe the pathways by which cells obtain energy.
Chapter Intro-page 220 What Youll Learn You will compare ATP production in mitochondria and in chloroplasts.
9.1 Section Objectives – page 221 Explain why organisms need a supply of energy. Section Objectives: Describe how energy is stored and released by ATP.
Section 9.1 Summary – pages 221-224 All living organisms must be able to obtain energy from the environment in which they live. Plants and other green organisms are able to trap the light energy in sunlight and store it in the bonds of certain molecules for later use. Cell Energy
Section 9.1 Summary – pages 221-224 Other organisms cannot use sunlight directly. They eat green plants. In that way, they obtain the energy stored in plants. Cell Energy
Section 9.1 Summary – pages 221-224 Active transport, cell division, movement of flagella or cilia, and the production, transport, and storage of proteins are some examples of cell processes that require energy. Work and the need for energy There is a molecule in your cells that is a quick source of energy for any organelle in the cell that needs it.
Section 9.1 Summary – pages 221-224 The name of this energy molecule is adenosine triphosphate or ATP for short. ATP is composed of an adenosine molecule with three phosphate groups attached. Work and the need for energy
Section 9.1 Summary – pages 221-224 The charged phosphate groups act like the positive poles of two magnets. Bonding three phosphate groups to form adenosine triphosphate requires considerable energy. Forming and Breaking Down ATP
Section 9.1 Summary – pages 221-224 When only one phosphate group bonds, a small amount of energy is required and the chemical bond does not store much energy. This molecule is called adenosine monophosphate (AMP). Forming and Breaking Down ATP When a second phosphate group is added, more energy is required to force the two groups together. This molecule is called adenosine diphosphate, or ADP.
Section 9.1 Summary – pages 221-224 An even greater amount of energy is required to force a third charged phosphate group close enough to the other two to form a bond. When this bond is broken, energy is released. Forming and Breaking Down ATP
Section 9.1 Summary – pages 221-224 The energy of ATP becomes available to a cell when the molecule is broken down. Adenosine PPP P P PP Adenosine triphosphate (ATP) Adenosine diphosphate (ADP) Forming and Breaking Down ATP
Section 9.1 Summary – pages 221-224 When ATP is broken down and the energy is released, the energy must be captured and used efficiently by cells. Many proteins have a specific site where ATP can bind. How cells tap into the energy stored in ATP
Section 9.1 Summary – pages 221-224 Then, when the phosphate bond is broken and the energy released, the cell can use the energy for activities such as making a protein or transporting molecules through the plasma membrane. ATP ADP Protein P Energy How cells tap into the energy stored in ATP
Section 9.1 Summary – pages 221-224 When ATP has been broken down to ADP, the ADP is released from the binding site in the protein and the binding site may then be filled by another ATP molecule. How cells tap into the energy stored in ATP
Section 1 Check Question 1 What is the primary difference in the ways that plants and animals obtain energy? Answer All living organisms need energy. Plants can trap light energy in sunlight and store it for later use. Animals cannot trap energy from sunlight and must eat plants that contain stored energy. FL: SC.B.1.4.1
Section 1 Check Question 2 Why does the formation of ATP require energy? FL: SC.B.1.4.1
Section 1 Check One molecule of ATP contains three phosphate groups, which are charged particles. Energy is required to bond the phosphate groups onto the same molecule because they behave the same way that the poles of magnets do and repel groups with like charges. When the ATP molecule is broken down, the chemical energy stored in it becomes available to the cell for life processes. FL: SC.B.1.4.1
Section 1 Check Question 3 A molecule of adenosine that has one phosphate group bonded to it is ______. A. AMP B. ADP C. ATP D. ACP
Section 1 Check The answer is A. AMP is adenosine monophosphate. The addition and release of a phosphate group on adenosine diphosphate creates a cycle of ATP formation and breakdown. Adenosine PPP P P PP Adenosine triphosphate (ATP) Adenosine diphosphate (ADP)
Section 1 Check Question 4 What is the function of the protein molecule shown in this diagram? ATP ADP Protein P Energy FL: SC.F.1.4.5
Section 1 Check This protein molecule has a specific binding site for ATP. In order to access the energy stored ATP, the protein molecule binds the ATP and uncouples one phosphate group. This action releases energy that is then available to the cell. ATP ADP Protein P Energy FL: SC.F.1.4.5
9.2 Section Objectives – page 225 Relate the structure of chloroplasts to the events in photosynthesis. Section Objectives: Describe light-dependent reactions. Explain the reactions and products of the light-independent Calvin cycle.
Section 9.2 Summary – pages 225-230 Trapping Energy from Sunlight The process that uses the suns energy to make simple sugars is called photosynthesis.
1.The light-dependent reactions convert light energy into chemical energy. Section 9.2 Summary – pages 225-230 Photosynthesis happens in two phases. 2. The molecules of ATP produced in the light- dependent reactions are then used to fuel the light-independent reactions that produce simple sugars. The general equation for photosynthesis is written as 6CO 2 + 6H 2 OC 6 H 12 O 6 + 6O 2 Trapping Energy from Sunlight
Section 9.2 Summary – pages 225-230 Click image to view movie. Trapping Energy from Sunlight
Section 9.2 Summary – pages 225-230 The chloroplast and pigments To trap the energy in the suns light, the thylakoid membranes contain pigments, molecules that absorb specific wavelengths of sunlight. Although a photosystem contains several kinds of pigments, the most common is chlorophyll. Chlorophyll absorbs most wavelengths of light except green.
Section 9.2 Summary – pages 225-230 Light-Dependent Reactions As sunlight strikes the chlorophyll molecules in a photosystem of the thylakoid membrane, the energy in the light is transferred to electrons. These highly energized, or excited, electrons are passed from chlorophyll to an electron transport chain, a series of proteins embedded in the thylakoid membrane.
Section 9.2 Summary – pages 225-230 Light-Dependent Reactions Sun Chlorophyll passes energy down through the electron transport chain. for the use in light-independent reactions bonds P to ADP forming ATP oxygen released splits H 2 O H+H+ NADP + NADPH Light energy transfers to chlorophyll. Energized electrons provide energy that At each step along the transport chain, the electrons lose energy.
Section 9.2 Summary – pages 225-230 This lost energy can be used to form ATP from ADP, or to pump hydrogen ions into the center of the thylakoid disc. Electrons are re-energized in a second photosystem and passed down a second electron transport chain. Light-Dependent Reactions
Section 9.2 Summary – pages 225-230 The electrons are transferred to the stroma of the chloroplast. To do this, an electron carrier molecule called NADP is used. NADP can combine with two excited electrons and a hydrogen ion (H + ) to become NADPH. NADPH will play an important role in the light-independent reactions. Light-Dependent Reactions
Section 9.2 Summary – pages 225-230 Restoring electrons To replace the lost electrons, molecules of water are split in the first photosystem. This reaction is called photolysis. Sun Chlorophyll 2e - H2OH2O O 2 + 2H + 1 _ 2 H 2 O 2 _ 1 O 2 + 2e -
Section 9.2 Summary – pages 225-230 The oxygen produced by photolysis is released into the air and supplies the oxygen we breathe. The electrons are returned to chlorophyll. The hydrogen ions are pumped into the thylakoid, where they accumulate in high concentration. Restoring electrons
Section 9.2 Summary – pages 225-230 Carbon fixation The carbon atom from CO 2 bonds with a five-carbon sugar called ribulose biphosphate (RuBP) to form an unstable six- carbon sugar. (CO 2 ) (RuBP) The stroma in chloroplasts hosts the Calvin cycle. The Calvin Cycle
Section 9.2 Summary – pages 225-230 Formation of 3- carbon molecules The six-carbon sugar formed in Step A immediately splits to form two three-carbon molecules. (Unstable intermediate) The Calvin Cycle
Section 9.2 Summary – pages 225-230 The Calvin Cycle Use of ATP and NADPH A series of reactions involving ATP and NADPH from the light- dependent reactions converts the three-carbon molecules into phosphoglyceraldehyde (PGAL), three-carbon sugars with higher energy bonds. ATP NADPH NADP+ (PGAL) ADP +
Section 9.2 Summary – pages 225-230 Sugar production One out of every six molecules of PGAL is transferred to the cytoplasm and used in the synthesis of sugars and other carbohydrates. After three rounds of the cycle, six molecules of PGAL are produced. (PGAL) (Sugars and other carbohydrates) The Calvin Cycle
Section 9.2 Summary – pages 225-230 RuBP is replenished Five molecules of PGAL, each with three carbon atoms, produce three molecules of the five-carbon RuBP. This replenishes the RuBP that was used up, and the cycle can continue. P ADP+ ATP (PGAL) The Calvin Cycle
Section 2 Check The process that uses the suns energy to make simple sugars is ________. Question 1 D. photolysis C. photosynthesis B. glycolysis A. cellular respiration FL: SC.B.1.4.1
Section 2 Check The answer is C. Photosynthesis happens in two phases to make simple sugars and convert the sugars into complex carbohydrates for energy storage. FL: SC.B.1.4.1
Section 2 Check The function accomplished by the light- dependent reactions is ________. Question 2 D. conversion of sugar to PGAL C. carbon fixation B. sugar production A. energy storage FL: SC.B.1.4.1
Section 2 Check The answer is A. The light-dependent reactions transfer energy from the sun to chlorophyll, and pass energized electrons to proteins embedded in the thylakoid membrane for storage in ATP and NADPH molecules. Sun Chlorophyll passes energy down through the electron transport chain. for the use in light-independent reactions bonds P to ADP forming ATP oxygen released splits H 2 O H+H+ NADP + NADPH Light energy transfers to chlorophyll. Energized electrons provide energy that FL: SC.B.1.4.1
Section 2 Check The first step in the Calvin cycle is the ________. Question 3 D. Bonding of carbon to ribulose biphosphate C. Splitting of six-carbon sugar into two three-carbon molecules B. production of phosphoglyceraldehyde A. replenishing of ribulose biphosphate FL: SC.F.1.4.5
Section 2 Check The answer is D. The carbon atom from CO 2 bonds with a five-carbon sugar to form an unstable six-carbon sugar. This molecule then splits to form two three-carbon molecules. FL: SC.F.1.4.5
Section 2 Check How many rounds of the Calvin cycle must occur in order for one molecule of PGAL to be transferred to the cells cytoplasm? Question 4 D. 4 C. 3 B. 2 A. 1 FL: SC.F.1.4.5
Section 2 Check The answer is C. Each round of the Calvin cycle produces two molecules of PGAL. FL: SC.F.1.4.5
9.3 Section Objectives – page 231 Compare and contrast cellular respiration and fermentation. Section Objectives: Explain how cells obtain energy from cellular respiration.
Section 9.3 Summary – pages 231-237 Cellular Respiration The process by which mitochondria break down food molecules to produce ATP is called cellular respiration. There are three stages of cellular respiration: glycolysis, the citric acid cycle, and the electron transport chain.
Section 9.3 Summary – pages 231-237 Cellular Respiration The first stage, glycolysis, is anaerobicno oxygen is required. The last two stages are aerobic and require oxygen to be completed.
Section 9.3 Summary – pages 231-237 Glycolysis Glycolysis is a series of chemical reactions in the cytoplasm of a cell that break down glucose, a six-carbon compound, into two molecules of pyruvic acid, a three-carbon compound. Glucose 2ATP 2ADP 2PGAL 4ADP + 4P 2NAD+ 2NADH + 2H + 4ATP 2 Pyruvic acid
Section 9.3 Summary – pages 231-237 Glycolysis is not very effective, producing only two ATP molecules for each glucose molecule broken down. Glucose 2ATP 2ADP 2PGAL 4ADP + 4P 2NAD+ 2NADH + 2H + 4ATP 2 Pyruvic acid Glycolysis
Section 9.3 Summary – pages 231-237 Before citric acid cycle and electron transport chain can begin, pyruvic acid undergoes a series of reactions in which it gives off a molecule of CO 2 and combines with a molecule called coenzyme A to form acetyl-CoA. Pyruvic acid Outside the mitochondrion Mitochondrial membrane Inside the mitochondrion Pyruvic acid Intermediate by-product NAD + NADH + H + CO 2 Coenzyme A - CoA Acetyl-CoA Glycolysis
Section 9.3 Summary – pages 231-237 The citric acid cycle The citric acid cycle, also called the Krebs cycle, is a series of chemical reactions similar to the Calvin cycle in that the molecule used in the first reaction is also one of the end products. For every turn of the cycle, one molecule of ATP and two molecules of carbon dioxide are produced.
Section 9.3 Summary – pages 231-237 The electron transport chain In the electron transport chain, the carrier molecules NADH and FADH 2 gives up electrons that pass through a series of reactions. Oxygen is the final electron acceptor. Overall, the electron transport chain adds 32 ATP molecules to the four already produced.
Section 9.3 Summary – pages 231-237 The electron transport chain
Section 9.3 Summary – pages 231-237 Fermentation During heavy exercise, when your cells are without oxygen for a short period of time, an anaerobic process called fermentation follows glycolysis and provides a means to continue producing ATP until oxygen is available again.
Section 9.3 Summary – pages 231-237 Lactic acid fermentation Lactic acid fermentation is one of the processes that supplies energy when oxygen is scarce. In this process, the reactions that produced pyruvic acid are reversed. Two molecules of pyruvic acid use NADH to form two molecules of lactic acid.
Section 9.3 Summary – pages 231-237 Lactic acid fermentation This releases NAD + to be used in glycolysis, allowing two ATP molecules to be formed for each glucose molecule. The lactic acid is transferred from muscle cells, to the liver that converts it back to pyruvic acid.
Section 9.3 Summary – pages 231-237 Alcoholic fermentation Another type of fermentation, alcoholic fermentation, is used by yeast cells and some bacteria to produce CO 2 and ethyl alcohol.
Section 9.3 Summary – pages 231-237 Comparing Photosynthesis and Cellular Respiration Photosynthesis Cellular Respiration Food synthesized Food broken down Energy from sun stored in glucose Energy of glucose released Carbon dioxide taken in Carbon dioxide given off Oxygen given off Oxygen taken in Produces sugars from PGALProduces CO2 and H 2 O Requires light Does not require light Occurs only in presence of chlorophyll Occurs in all living cells Table 9.1 Comparison of Photosynthesis and Cellular Respiration
Section 3 Check What do the Calvin cycle and the Citric acid cycle have in common? Question 1 D. From every turn of the cycle, two molecules of carbon dioxide are produced. C. Both generate ADP. B. Both require input of ATP molecules. A. The molecule used in the first reaction is also one of the end products. FL: SC.F.1.4.5
Section 3 Check The answer is A. In the Calvin cycle, RuBP bonds to carbon in the first step and is produced in the last step. In the citric acid cycle, oxaloacetic acid reacts in the first step and is recycled in the last step. FL: SC.F.1.4.5
Section 3 Check The process by which mitochondria break down food molecules to produce ATP is called ________. Question 2 D. the Calvin cycle C. the light-independent reaction B. cellular respiration A. photosynthesis FL: SC.B.1.4.1, SC.F.1.4.5
Section 3 Check The answer is B. Photosynthesis, light- independent reactions, and the Calvin cycle all occur in plants. FL: SC.B.1.4.1, SC.F.1.4.5
Section 3 Check The three stages of cellular respiration are ________. Question 3 B. carbon fixation, the citric acid cycle, and the electron transport chain A. glycolysis, the Calvin cycle, and the electron transport chain FL: SC.B.1.4.1
Section 3 Check The three stages of cellular respiration are ________. Question 3 D. the light-dependent reactions, the citric acid cycle and the electron transport chain C. glycolysis, the citric acid cycle, and the electron transport chain FL: SC.B.1.4.1
Section 3 Check The answer is C. The first stage is anaerobic, but the last two stages require oxygen to be completed. FL: SC.B.1.4.1
Section 3 Check Which of the following yields the greatest net ATP? Question 4 D. Cellular respiration C. Calvin cycle B. Alcoholic fermentation A. Lactic acid fermentation FL: SC.B.1.4.1
Section 3 Check The answer is D. Cellular respiration is far more efficient in ATP production than the fermentation reactions. Comparison of Fermentation to Cellular Respiration Lactic Acid AlcoholicCellular respiration glucose glycolysis (pyruvic acid) lactic acid 2 ATP glucose glycolysis (pyruvic acid) carbon dioxide alcohol 2 ATP38 ATP water carbon dioxide FL: SC.B.1.4.1
Chapter Summary – 9.1 ATP is the molecule that stores energy for easy use within the cell. The Need for Energy ATP is formed when a phosphate group is added to ADP. When ATP is broken down, ADP and phosphate are formed and energy is released. Green organisms trap the energy in sunlight and store it in the bonds of certain molecules for later use.
Chapter Summary – 9.1 Organisms that cannot use sunlight directly obtain energy by consuming plants or other organisms that have consumed plants. The Need for Energy
Chapter Summary – 9.2 Photosynthesis is the process by which cells use light energy to make simple sugars. Chlorophyll in the chloroplasts of plant cells traps light energy needed for photosynthesis. The light reactions of photosynthesis produce ATP and result in the splitting of water molecules. Photosynthesis: Trapping the Suns Energy
Chapter Summary – 9.2 Photosynthesis: Trapping the Suns Energy The reactions of the Calvin Cycle make carbohydrates using CO 2 along with ATP and NADPH from the light reactions.
Chapter Summary – 9.3 Getting Energy to Make ATP In cellular respiration, cells break down carbohydrates to release energy. The first stage of cellular respiration, glycolysis, takes place in the cytoplasm and does not require oxygen. The citric acid cycle takes place in mitochondria and requires oxygen.
Chapter Assessment Question 1 Name two differences between photosynthesis and cellular respiration. FL: SC.B.1.4.1
Photosynthesis Cellular Respiration Food synthesized Food broken down Energy from sun stored in glucose Energy of glucose released Carbon dioxide taken in Carbon dioxide given off Oxygen given off Oxygen taken in Produces sugars from PGALProduces CO2 and H 2 O Requires light Does not require light Occurs only in presence of chlorophyll Occurs in all living cells Table 9.1 Comparison of Photosynthesis and Cellular Respiration Although both processes use electron carriers and form ATP, they accomplish quite different tasks as shown in the table. Chapter Assessment FL: SC.B.1.4.1
Chapter Assessment Question 2 Choose the word from this list that does NOT belong with the others. A. oxaloacetic acid B. FADH 2 C. Acetyl-CoA D. ribulose biphosphate FL: SC.F.1.4.5
The answer is D. RuBP is utilized in the Calvin cycle; the others are part of the citric acid cycle. Chapter Assessment FL: SC.F.1.4.5
Chapter Assessment Question 3 Six molecules of glucose would give a net yield of _____ ATP following glycolysis. A. 8 B. 16 C. 6 D. 12 FL: SC.F.1.4.5
The answer is D. Glycolysis produces two ATP molecules for each glucose molecule broken down. Chapter Assessment FL: SC.F.1.4.5
Chapter Assessment Question 4 In which of the following structures do the light-dependent reactions of photosynthesis take place? A. B. C. D. FL: SC.B.1.4.1
The answer is D. The light-dependent reactions of photosynthesis take place in the thylakoid membranes of chloroplasts. Chapter Assessment FL: SC.B.1.4.1
Chapter Assessment Question 5 In which stage of photosynthesis is carbon from CO 2 used to form a six-carbon sugar? A. Calvin cycle B. glycolysis C. citric acid cycle D. electron transport chain FL: SC.B.1.4.1
Chapter Assessment (CO 2 ) (Unstable intermediate) ATP ADP + (Sugars and other carbohydrates) NADPH NADP + (PGAL) ATP (PGAL) (RuPB) The answer is A. FL: SC.B.1.4.1
Chapter Assessment Question 6 What component of thylakoid membranes absorbs specific wavelengths of sunlight? A. electrons B. pigments C. chloroplasts D. mitochondria FL: SC.F.1.4.3
The answer is B. Pigments are arranged within the thylakoid membranes in photosystems; the most common pigment is chlorophyll. Chapter Assessment FL: SC.F.1.4.3
Chapter Assessment Question 7 Which of the following is a product of cellular respiration? A. lactic acid B. alcohol C. glucose D. carbon dioxide FL: SC.B.1.4.1
The answer is D. Carbon dioxide, water, and ATP are the products of cellular respiration. Chapter Assessment FL: SC.B.1.4.1
Chapter Assessment Question 8 Complete the concept map using the following terms: RuBP replenishing, formation of 3-carbon molecules, Calvin cycle, carbon fixation. are steps in which takes place in stroma 1 23 4 FL: SC.F.1.4.5
Completed concept map should reflect carbon fixation, RuBP replenishing, and formation of 3-carbon molecules as steps in the Calvin cycle which takes place in stroma. Chapter Assessment FL: SC.F.1.4.5
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