Campbell Biology PDF: Photosynthesis - Chapter 7

Campbell Biology: Concepts & Connections Tenth Edition Chapter 7 Photosynthesis: Using Light to Make Food Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Introduction Biofuels are energy so...

Campbell Biology: Concepts & Connections Tenth Edition Chapter 7 Photosynthesis: Using Light to Make Food Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Introduction Biofuels are energy sources obtained from living material. When we derive energy from biofuels, we are tapping into the energy of the sun. In living cells, this same solar energy is converted to the chemical energy of sugar through the process of photosynthesis. This chapter focuses on how photosynthesis works. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.0_1 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Catabolic breakdow el Respiration ne do Exergo - - tomcon Co 20 Go # > - > => => => 6H 6 6 + 2 0 Energy => light/ CgHzOp + 0 2 Anabolic (brid) · Do O o g org Endergonit usea > -. · Do 0 o 000 · Do  Photosynthesis CO2 Light Chloroplast ⑪ ↓ ↓ H20 ↓ NADP kid 7 The ↳ -&Lightion d NADPH1 ) (e - + H+ ↓ Oz gar" ↓ Letroma Oz Figure 7.0_2 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. An Introduction to Photosynthesis Copyright © 2020 Pearson Education, Inc. All Rights Reserved.  7.1 Photosynthesis Powers Most Life on Earth Plants, algae, and some photosynthetic protists and bacteria are photoautotrophs, the producers of food consumed by heterotrophic organisms. G Heterotrophs are consumers that feed on plants or others animals or decompose organic material. Checkpoint question What do “self-feeding” photoautotrophs require from the environment to make their own food? Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.1 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.1a Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.1b Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.1c Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.2 Photosynthesis Occurs in - Chloroplasts in Plant Cells - Chloroplasts are surrounded by a double membrane and contain stacks of thylakoids and a thick fluid called stroma. Chlorophyll is a light-absorbing pigment in the chloroplasts that plays a central role in converting solar energy to chemical energy. Checkpoint question How do the reactant molecules of photosynthesis reach the chloroplasts in leaves? Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.2 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.2_1 - Chloroplasts = S O Stomata = Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.2_2 & Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.2_3 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.2_4 (Gna) Thakoic) - Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.3 Scientists Traced the Process of Photosynthesis Using Isotopes (1 of 2) Experiments using both heavy and radioactive isotopes helped determine the details of the process of photosynthesis. Using a heavy isotope of oxygen, O-18, scientists were able to follow the fate of oxygen atoms during photosynthesis. The results were that plants produced O2 containing O-18 only when supplied with labeled H2O, never when provided with labeled C O2. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.3 Scientists Traced the Process of Photosynthesis Using Isotopes (2 of 2) Experiment 1: 6C O 2 + 12H2O → C6 H12O6 + 6H2O + 6O2 Experiment 2: 6C O 2 + 12H2O → C6H12O6 + 6H2O + 6O2 Checkpoint question Photosynthesis produces billions of tons of carbohydrate a year. Where does most of the mass of this huge amount of organic matter come from? Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.UN01 ⑳ & S - Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.3 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.4 Photosynthesis Is a Redox Process Photosynthesis, like respiration, is a redox (oxidation-reduction) process. – In photosynthesis, H 2 O is oxidized and C O 2 is reduced. – Cellular respiration uses redox reactions to harvest the chemical energy stored in a glucose molecule. Checkpoint question Which redox process, photosynthesis or cellular respiration, is exergonic? Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.4 1 - & Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.5 Photosynthesis Occurs in Two Stages, Which Are Linked by A T P and N A D P H The light reactions occur on and inside the thylakoids, producing A T P and N A D P H for the Calvin cycle, which takes place in the stroma. During the Calvin cycle, C O2 is incorporated into organic compounds in a process called carbon fixation. Checkpoint question For chloroplasts to produce sugar from carbon dioxide in the dark, they would need to be supplied with ________ and ________. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.5a Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.5b_1 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.5b_2 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.5b_3 Copyright © 2020 Pearson Education, Inc. All Rights Reserved.  The Light Reactions: Converting Solar Energy to Chemical Energy Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.6 Visible Radiation Absorbed by Pigments Drives the Light Reactions Sunlight is a type of energy called electromagnetic energy or radiation. – Certain wavelengths of visible light are absorbed by chlorophyll and other pigments. – Carotenoids also function in photoprotection from excessive light. Checkpoint question What color of light is least effective at driving photosynthesis? Explain. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.6a Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.6b harphyll Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.6b_1 % Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.6b_2 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.7 Photosystems Capture Solar Energy Thylakoid membranes contain photosystems, each consisting of light-harvesting complexes and a reaction-center complex. A primary electron acceptor receives photoexcited electrons from reaction-center chlorophyll a. Checkpoint question Compared with a solution of isolated chlorophyll, why do intact chloroplasts not release heat and light when illuminated? Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.7a Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.7a_1 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.7a_2 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.7b Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Animation: Light and Pigments Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.8 Two Photosystems Connected by an Electron Transport Chain Convert Light Energy to the Chemical Energy of A T P and N A D P H (1 of 2) Electrons shuttle from photosystem Ⅱ to photosystem Ⅰ, providing energy to make A T P, and then reduce N A D P+ to N A D P H. Photosystem Ⅱ regains electrons as water is split and O2 released. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.8 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.8 Two Photosystems Connected by an Electron Transport Chain Convert Light Energy to the Chemical Energy of A T P and N A D P H (2 of 2) Checkpoint question Looking at the model of the light reactions in Figure 7.8, explain why two photons of light are required in the movement of electrons from water to N A D P H. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.9 Visualizing the Concept: The Light Reactions Take Place Within the Thylakoid Membranes In photophosphorylation, the electron transport chain pumps H+ into the thylakoid space. The concentration gradient drives H+ back through ATP synthase, powering the synthesis of ATP. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.9 ec Hint Oz Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.9_1 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.9_2 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.9_3 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.9_4 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.9_5 8 Copyright © 2020 Pearson Education, Inc. All Rights Reserved.  Calvin Cycle (15) ⑳ ⑳ ⑳go 3(C) & " O Carbon Grabbin RuBP 9 - 3 Fixation ③. ⑮ T O Regeneration Of Rub p Calvin Goo GATP E S 0-0 0 - Cycle 000 ADD 00-01 ATP 000 ⑳ "Sugar Making" GNADPH 3 - Deduction NADPT 2000 0-0 0 GoG - 0-0-0 0-0-6 ⑳34 0006-0 C (02) Calvin Cycle(BCO 00 ↓ 000 - 0 2 (c) #52)y ⑳ R 000 ⑪ Carbon · Co Raphael - - Grabbing is - G A ( ③ ~ 00 ② 11 " Sugar Making Reduction - r 000000 0-0000-0 6 3P  NADP Light H2O Light Le & its As Waste Thylakoid membrane - thase ↳ 9 Reaction  600 Can Cycle G 3202 ~ -· GO T - If - - - -... r ① Carbon Exation M - - - 31 - - - "Carbon Grabbing" & · Reed (59) · (0e) 0000-0 200 ③ · 000-0-G A I "Sugar Makina Y ⑳ - GSNADPH · 62P(8C) - ·  Test Structure - ·I Photosynthesis - 45 % 45 % - & Do : >0 > - - - Anabolic - Endergonic RX - I Law of Energy Light (eatalyst) & Glycolysis Enzyme - 2) Krebs Cycle - makes i lib - 3) He - similarities - - - ufferences  Similarities b/m Resp (Photosynthesis. - ATTP - Both involve - - - both - use ATP Synthase t H+ gradients - Conversion - Energy - - - multiple steps t-stages - Both use "eles" (ke/Calvin) - Final Electron Acceptors  Differences Photosynthesis = Mitochondria - Oz - - source cose/Food i Energy ~ fameron undergonic - EgoLihts Eergonic CottinOut on Ho CaHizOg + - - The Calvin Cycle: Reducing C O2 to Sugar Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.10 ATP and NADPH Power Sugar Synthesis in the Calvin Cycle The steps of the Calvin cycle include – carbon fixation, – reduction, – release of G 3 P, and – regeneration of R u B P. Using carbon from C O2, electrons from N A D P H, and energy from A T P, the cycle constructs G 3 P, which is used to build glucose and other organic molecules. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.10 Copyright © 2020 Pearson Education, Inc. All Rights Reserved.  o E.... 320 -- P · Carbon ↳ - Fixation Cal vi a ) "Carbon -- Grabbing" S - 000 (oc) Y 20 Eyele (5) A 0-0-0-0 00000 => 0 - ② Reduction (addenergyy ③ m Restock 000 - ↓ RUBP 000 000 ⑳00 ⑮ 00-0 ADPP GEP NADP + - · Endergonic Anabolic - = ⑮ 8 · - 0-0-G => o - ↑ Figure 7.10_1 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.10_2 in Rikulosephosphate Copyright © 2020 Pearson Education, Inc. All Rights Reserved.  Differences Res S. Photosynthesis - to · Breaks down Sugar ⑧ Sugar Builds to Release Energy Store Energy Source is Sugar · Energy Source Light/H20 · Energy intermembrane · H + storage in Thylakoid · Ition stored space Mitochondria ~ Chloroplast autotrophsonly · all living things & · Done by -  Similarities - · Both are used in plants · Both have cycles involve at p · Both -Both have AtP Synthase similar energy carriers · Both use · Both use ETC's = d H+ gradients  ⑳ · · bo ! 15C · D a - 0-0-6 · 0-0-0-0-6 182 ③ 00-0- T onc ⑨ Go-o- 06 o ②on making) (sar RuBP - SATP - ⑧ ↳ ↓ ⑧ ⑳ ⑳ GNADPH # Figure 7.10_3_1 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.10_3_2 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.10_3_3 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.10_3_4 D 00-0 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.11 Evolution Connection: Other Methods of Carbon Fixation Have Evolved in Hot, Dry Climates E In=C3 plants, > a drop in C O2 and rise in O2 when stomata 2 close divert the Calvin cycle to photorespiration. - C plants and C A M plants first fix C O 4 => - into four-carbon 2 compounds that provide C O2 to the Calvin cycle even when stomata close on hot, dry days. Checkpoint question Why would you expect photorespiration on a hot, dry day to occur less in C4 and C A M plants than in C3 plants? Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.11 C > = => Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.11_1 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.11_2 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.11_3 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. The Global Significance of Photosynthesis Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.12 Photosynthesis Provides Food and O2 For Almost All Living Organisms (1 of 2) Cellular respiration in the mitochondria of plant cells uses about 50% of the carbohydrates made by photosynthesis. Sugars also serve as starting material for making other organic molecules, such as proteins and lipids. Glucose molecules are linked together to make cellulose, the main component of cell walls. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.12 Photosynthesis Provides Food and O2 For Almost All Living Organisms (2 of 2) Checkpoint question Explain this statement: No process is more important to the welfare of life on Earth than photosynthesis. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.12 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.12_1 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.13 Scientific Thinking: Rising Atmospheric Levels of Carbon Dioxide May Affect Plants in Various Ways Scientists study the effects of rising C O2 levels using laboratory growth chambers and field studies. Long-term field projects enable scientists to assess the effects of C O2 levels on natural ecosystems. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.13a Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.13b Source: Adaptation of Figure 1A from “Biomass and toxicity responses of poison ivy (Toxicodendron radicans) to elevated atmospheric C O2” by Jacqueline E. Mohan, et al., from P N A S, June 2006, Volume 103(24). National Academy of Sciences. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.14 Connection: Reducing Both Fossil Fuel Use and Deforestation May Moderate Climate Change (1 of 2) C O2 and other gases in the atmosphere create the greenhouse effect. Global warming is a major aspect of climate change, a long-term directional change to the global climate that lasts for three decades or more. An international agreement reached at the Paris climate conference of 2015 seeks to reduce greenhouse gas emissions and limit global warming. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. 7.14 Connection: Reducing Both Fossil Fuel Use and Deforestation May Moderate Climate Change (2 of 2) Checkpoint question Explain the greenhouse effect. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.14a Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.14b Copyright © 2020 Pearson Education, Inc. All Rights Reserved. You Should Now Be Able to (1 of 3) 1. Define autotrophs, heterotrophs, producers, and photoautotrophs. 2. Describe the structure of chloroplasts and their location in a leaf. 3. Explain how plants produce oxygen. 4. Describe the role of redox reactions in photosynthesis and cellular respiration. 5. Compare the reactants and products of the light reactions and the Calvin cycle. Copyright © 2020 Pearson Education, Inc. All Rights Reserved.  You Should Now Be Able to (2 of 3) 6. Describe the properties and functions of the different photosynthetic pigments. 7. Explain how photosystems capture solar energy. 8. Explain how the electron transport chain and chemiosmosis generate ATP, NADPH, and oxygen in the light reactions. 9. Compare photophosphorylation and oxidative phosphorylation. 10. Describe the reactants and products of the Calvin cycle. Copyright © 2020 Pearson Education, Inc. All Rights Reserved.  You Should Now Be Able to (3 of 3) 11. Compare the mechanisms that C3, C4, and CAM plants use to obtain and use carbon dioxide. 12. Review the overall process of the light reactions and the Calvin cycle, noting the reactants, products, and locations of every major step. 13. Describe the greenhouse effect. 14. Explain how reducing the use of fossil fuels and deforestation may moderate climate change. Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.UN02 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.UN03 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Figure 7.UN04 Copyright © 2020 Pearson Education, Inc. All Rights Reserved. Copyright This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching their courses and assessing student learning. Dissemination or sale of any part of this work (including on the World Wide Web) will destroy the integrity of the work and is not permitted. The work and materials from it should never be made available to students except by instructors using the accompanying text in their classes. 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