Photosynthesis Chapter 5 PDF

Chapter 5 Photosynthesis Left: © Christian Kober/Getty Images Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Sunlight Powers Photosynthesis This seedling is...

Chapter 5 Photosynthesis Left: © Christian Kober/Getty Images Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Sunlight Powers Photosynthesis This seedling is soaking up the sun. Within its leaves, photosynthesis is converting sunlight into food. Sprout: © Corbis (RF) Section 5.1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Sunlight Powers Photosynthesis Plants need few simple ingredients to make their own food: - Sunlight - Carbon dioxide (CO2) - Water Sprout: © Corbis (RF) Section 5.1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Sunlight Powers Photosynthesis plants use these simple ingredients to make sugars, like glucose. Sprout: © Corbis (RF); "Electron micrograph by Wm. P. Wergin, courtesy of Eldon H. Newcomb, University of Wisconsin-Madison." Section 5.1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.1  Life Depends On Photosynthesis Without photosynthesis, neither the plants nor the animal in this image would survive. Section 5.1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 4.2  Life Depends On Photosynthesis Photosynthesis is essential to sustaining life on Earth. Section 5.1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 4.2  Question #1 Evolution favored the development of photosynthesis because photosynthetic organisms: A. produce oxygen. B. make their own food. C. make food for heterotrophs. D. use carbon dioxide. E. All of the choices are correct. © 1996 PhotoDisc, Inc./Getty Images/RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  5.1 Mastering Concepts Why is photosynthesis essential to life? © 1996 PhotoDisc, Inc./Getty Images/RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  The Sun Emits a Spectrum of Wavelengths Short wavelength (high energy) Gamma rays Visible light X-rays 400 Violet Wavelength in nanometers 450 Blue Portion of Cyan Ultraviolet 500 spectrum Green radiation 550 that Yellow reaches 600 Orange Earth's Infrared radiation 650 Wavelength surface 700 Red Microwaves 750 Radio waves Long wavelength (low energy) The sun releases energy in waves. Section 5.2 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.2  The Sun Emits a Spectrum of Wavelengths Short wavelength (high energy) Gamma rays Visible light X-rays 400 Violet Wavelength in nanometers 450 Blue Portion of Cyan Ultraviolet 500 spectrum Green radiation 550 that Yellow reaches 600 Orange Earth's Infrared radiation 650 Wavelength surface 700 Red Microwaves 750 Radio waves Long wavelength (low energy) Shorter wavelengths have higher energy than longer wavelengths. Section 5.2 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.2  The Sun Emits a Spectrum of Wavelengths Short wavelength (high energy) Gamma rays Visible light X-rays 400 Violet Wavelength in nanometers 450 Blue Portion of Cyan Ultraviolet 500 spectrum Green radiation 550 that Yellow reaches 600 Orange Earth's Infrared radiation 650 Wavelength surface 700 Red Microwaves 750 Radio waves Long wavelength (low energy) Wavelengths visible to us are perceived as colors. Section 5.2 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.2  Photosynthetic Pigments Capture Sunlight Photosynthetic pigments Chlorophyll a Chlorophyll b Different Sunlight 80 Carotenoids Reflected pigments Relative absorption (percent) light 60 absorb different 40 wavelengths. 20 0 400 500 600 700 Wavelength of light (nanometers) Plant pigments capture visible light Section 5.2 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.3  Photosynthetic Pigments Capture Sunlight Photosynthetic pigments No pigment Chlorophyll a absorbs green Chlorophyll b 80 Carotenoids Sunlight Reflected light-it is Relative absorption (percent) light 60 reflected-we see green 40 leaves 20 0 400 500 600 700 Wavelength of light (nanometers) Section 5.2 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.3  Clicker Question #2 Why are leaves green? A. Heterotrophs see green better than any other color. B. Plant pigments absorb green light. C. Plant pigments absorb almost every wavelength except for green. D. Plant pigments change yellow light that they absorb to green light that we see. © 1996 PhotoDisc, Inc./Getty Images/RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 5.2 Mastering Concepts What is the relationship between visible light and the electromagnetic spectrum? © 1996 PhotoDisc, Inc./Getty Images/RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Photosynthesis Occurs in the Chloroplasts Gas exchange occurs at leaf pores called stomata. Mesophyll cells Stoma CO2 O2 + H 2 O Section 5.3 Leaves: ©Steve Raymer/NGS Image Collection Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.4  Photosynthesis Occurs in the Chloroplasts Each leaf contains many mesophyll cells. Mesophyll cells Mesophyll cell CO2 O2 +HO 2 Nucleus Central Mitochondrion vacuole Chloroplasts TEM 15 µm (false color) Leaves: ©Steve Raymer/NGS Image Collection; Section 5.3 Figure 5.4 "Electron micrograph by Wm. P. Wergin, courtesy of Eldon H. Newcomb, University of Wisconsin-Madison." Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Photosynthesis Occurs in the Chloroplasts Each mesophyll cell contains several chloroplasts. Mesophyll cell Chloroplast Outer DNA membrane Inner Central membrane vacuole Chloroplasts Stroma Granum Ribosomes TEM 15 µm (false color) Section 5.3 Figure 5.4 "Electron micrograph by Wm. P. Wergin, courtesy of Eldon H. Newcomb, University of Wisconsin-Madison." Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Photosynthesis Occurs in the Chloroplasts Each chloroplast contains several grana, or stacks of Mesophyll cell thylakoids. Chloroplast Outer DNA membrane Inner Central membrane vacuole Chloroplasts Stroma Granum Ribosomes 15 µm Granum Thylakoid Pigment molecules Thylakoid embedded in space thylakoid membrane Section 5.3 Figure 5.4 "Electron micrograph by Wm. P. Wergin, courtesy of Eldon H. Newcomb, University of Wisconsin-Madison." Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Photosynthesis Occurs in the Chloroplasts Pigment molecules in the thylakoid membrane Mesophyll cell capture sunlight. Chloroplast Outer DNA membrane Inner Central membrane vacuole Chloroplasts Stroma Granum Ribosomes 15 µm Granum Thylakoid Pigment molecules Thylakoid embedded in space thylakoid membrane Section 5.3 Figure 5.4 "Electron micrograph by Wm. P. Wergin, courtesy of Eldon H. Newcomb, University of Wisconsin-Madison." Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Photosynthesis Occurs in the Chloroplasts A photosystem is a large protein structure in the thylakoid membrane. Thylakoid space: Courtesy Professor SoIwata Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Section 5.3 Figure 5.5  Photosynthesis Occurs in the Chloroplasts Pigment molecules, such as chlorophyll, are embedded in photosystems. Thylakoid space: Courtesy Professor SoIwata Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Section 5.3 Figure 5.5  Question #3 Of the following list of plant structures, which is the second smallest? A. chloroplast B. granum C. mesophyll cell D. chlorophyll E. thylakoid © 1996 PhotoDisc, Inc./Getty Images/RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  5.3 Mastering Concepts Describe the relationship among the chloroplast, stroma, grana, and thylakoids. © 1996 PhotoDisc, Inc./Getty Images/RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Photosynthesis Occurs in Two Stages H2 O CO2 Light Chloroplast ATP Light NADPH Carbon reactions reactions NADP+ ADP O2 Glucose Section 5.4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.6  5.4 Mastering Concepts What happens in each of the two main stages of photosynthesis? © 1996 PhotoDisc, Inc./Getty Images/RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Light reactions capture sunlight energy H2 O CO2 Light Chloroplast ATP Light NADPH Carbon reactions reactions NADP+ ADP O2 Glucose Section 5.4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.6  The Light Reactions Begin Photosynthesis The light reactions occur in the thylakoids and require water and light. Section 5.5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.7  The Light Reactions Begin Photosynthesis ATP and NADPH are produced. Oxygen gas (O2) is a byproduct. Section 5.5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.7  The Light Reactions Begin Photosynthesis The photosystems are part of an electron transport chain that converts light energy into ATP and NADPH. Section 5.5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.7  The Light Reactions Begin Photosynthesis Photosystem II produces ATP - Light energy transferred to reaction center - Two electrons ejected Section 5.5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.7  The Light Reactions Begin Photosynthesis - Water is split to replace electrons - O2 is a byproduct Section 5.5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.7  The Light Reactions Begin Photosynthesis Photosystem II produces ATP - Ejected electrons move down transport chain Section 5.5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.7  The Light Reactions Begin Photosynthesis - H+ is pumped into thylakoid - H+ leaves through ATP synthase - ATP is produced Section 5.5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.7  The Light Reactions Begin Photosynthesis Photosystem I produces NADPH - Electrons reach photosystem I Section 5.5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.7  The Light Reactions Begin Photosynthesis Photosystem I produces NADPH - Electrons reach photosystem I - Energy from light again ejects electrons into a transport chain - Electrons reduce NADP+ to Section 5.5 NADPH Figure 5.7 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Question #4 How do the light reactions produce ATP? (Select the one best answer.) A. Potential energy stored in a hydrogen ion gradient is used to synthesize ATP. B. Photosystem I directly adds a phosphate to ADP. C. Photosystem II directly adds a phosphate to ADP. D. Energy released by electrons is directly used to synthesize ATP. © 1996 PhotoDisc, Inc./Getty Images/RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 5.5 Mastering Concepts Describe the events that occur after light strikes photosystem II, ending with the production of ATP. © 1996 PhotoDisc, Inc./Getty Images/RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Carbon reactions “Dark reactions” H2 O CO2 Light Chloroplast ATP Light NADPH Carbon reactions reactions NADP+ ADP O2 Glucose Section 5.6 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.6  Carbon Reactions Produce Carbohydrates The carbon reactions occur in the stroma. Section 5.6 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.8  Carbon Reactions Produce Carbohydrates Carbon reactions use carbon dioxide (CO2) and the ATP and NADPH produced in the light reactions to produce sugars. Section 5.6 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.8  Carbon Reactions Produce Carbohydrates CO2 These are the carbon reactions, also known as the Calvin cycle. Section 5.6 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.8  Carbon Reactions Produce Carbohydrates CO2 Step 1: Rubisco adds CO2 to RuBP An unstable 6- carbon molecule is produced Section 5.6 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.8  Clicker Question #5 How does a plant cell use the ATP that it produces in the light reactions? A. to fuel processes and reactions throughout the cell B. to fuel the carbon reactions C. to break down glucose D. to convert NADP+ to NADPH © 1996 PhotoDisc, Inc./Getty Images/RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  5.6 Mastering Concepts What are the roles of CO2, ATP, and NADPH in the Calvin cycle? © 1996 PhotoDisc, Inc./Getty Images/RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Products from G3P  Plants Use Different Carbon Fixation Pathways C3 plants, C4 plants, and CAM plants all use slightly different carbon fixation pathways. Section 5.7 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.9  Plants Use Different Carbon Fixation Pathways Notice the different leaf anatomy and Calvin cycle position. The Calvin cycle occurs here. Section 5.7 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 5.9  Plants Use Different Carbon Fixation Pathways Section 5.7 Figure 5.10 Tree: "© Tony Sweet/Digital Vision (RF)/Getty Images“; corn: © Joeseph Sohm-Visions of America/Getty Images (RF); cactus: © Digital Vision (RF)/Getty Images Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Plants Use Different Carbon Fixation Pathways Section 5.7 Figure 5.10 Tree: "© Tony Sweet/Digital Vision (RF)/Getty Images“; corn: © Joeseph Sohm-Visions of America/Getty Images (RF); cactus: © Digital Vision (RF)/Getty Images Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 5.7 Mastering Concepts How is the CAM pathway like C4 metabolism, and how is it different? © 1996 PhotoDisc, Inc./Getty Images/RF Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.