Speaker:王姿文
Date:2016-01-23
view(s): 587
  • 00:09 1.
    8
  • 00:29 2.
    Overview: The Process That Feeds the Biosphere
  • 00:52 3.
    Autotrophs sustain themselves without eating anything derived from other organisms Autotrophs are the producers of the biosphere, producing organic molecules from CO2 and other inorganic molecules Almost all plants are photoautotrophs, using the energy of
  • 00:26 4.
    Figure 8.1
  • 00:59 5.
    Heterotrophs obtain their organic material from other organisms Heterotrophs are the consumers of the biosphere Almost all heterotrophs, including humans, depend on photoautotrophs for food and O2
  • 00:47 6.
    Figure 8.2
  • 01:26 7.
    Concept 8.1: Photosynthesis converts light energy to the chemical energy of food
  • 00:42 8.
    Chloroplasts: The Sites of Photosynthesis in Plants
  • 00:44 9.
    CO2 enters and O2 exits the leaf through microscopic pores called stomata The chlorophyll is in the membranes of thylakoids (connected sacs in the chloroplast); thylakoids may be stacked in columns called grana Chloroplasts also contain stroma, a dense in
  • 00:00 10.
    Figure 8.3
  • 00:43 11.
    Figure 8.3
  • 00:39 12.
    Tracking Atoms Through Photosynthesis: Scientific Inquiry
  • 00:26 13.
    The Splitting of Water
  • 00:35 14.
    Figure 8.4
  • 00:43 15.
    Photosynthesis as a Redox Process
  • 00:19 16.
    Figure 8.UN01
  • 00:49 17.
    The Two Stages of Photosynthesis: A Preview
  • 00:59 18.
    Figure 8.5
  • 00:23 19.
    The Calvin cycle (in the stroma) forms sugar from CO2, using ATP and NADPH The Calvin cycle begins with carbon fixation, incorporating CO2 into organic molecules
  • 00:39 20.
    Concept 8.2: The light reactions convert solar energy to the chemical energy of ATP and NADPH
  • 00:37 21.
    The Nature of Sunlight
  • 00:45 22.
    The electromagnetic spectrum is the entire range of electromagnetic energy, or radiation Visible light consists of wavelengths (including those that drive photosynthesis) that produce colors we can see Light also behaves as though it consists of discrete
  • 01:00 23.
    Figure 8.6
  • 00:43 24.
    Photosynthetic Pigments: The Light Receptors
  • 00:46 25.
    Figure 8.7
  • 00:14 26.
    A spectrophotometer measures a pigment’s ability to absorb various wavelengths This machine sends light through pigments and measures the fraction of light transmitted at each wavelength
  • 01:21 27.
    Figure 8.8
  • 00:10 28.
    An absorption spectrum is a graph plotting a pigment’s light absorption versus wavelength The absorption spectrum of chlorophyll a suggests that violet-blue and red light work best for photosynthesis Accessory pigments include chlorophyll b and a group of
  • 00:22 29.
    Figure 8.8
  • 00:04 30.
    An absorption spectrum is a graph plotting a pigment’s light absorption versus wavelength The absorption spectrum of chlorophyll a suggests that violet-blue and red light work best for photosynthesis Accessory pigments include chlorophyll b and a group of
  • 02:24 31.
    Figure 8.9
  • 00:02 32.
    The action spectrum of photosynthesis was first demonstrated in 1883 by Theodor W. Engelmann In his experiment, he exposed different segments of a filamentous alga to different wavelengths Areas receiving wavelengths favorable to photosynthesis produced e
  • 00:15 33.
    The action spectrum of photosynthesis was first demonstrated in 1883 by Theodor W. Engelmann In his experiment, he exposed different segments of a filamentous alga to different wavelengths Areas receiving wavelengths favorable to photosynthesis produced e
  • 00:14 34.
    Chlorophyll a is the main photosynthetic pigment Accessory pigments, such as chlorophyll b, broaden the spectrum used for photosynthesis A slight structural difference between chlorophyll a and chlorophyll b causes them to absorb slightly different wavele
  • 00:30 35.
    Figure 8.10
  • 00:01 36.
    Excitation of Chlorophyll by Light
  • 00:43 37.
    Excitation of Chlorophyll by Light
  • 01:20 38.
    Figure 8.11
  • 00:01 39.
    A Photosystem: A Reaction-Center Complex Associated with Light-Harvesting Complexes
  • 01:07 40.
    A Photosystem: A Reaction-Center Complex Associated with Light-Harvesting Complexes
  • 01:04 41.
    Figure 8.12
  • 00:36 42.
    There are two types of photosystems in the thylakoid membrane Photosystem II (PS II) functions first (the numbers reflect order of discovery) and is best at absorbing a wavelength of 680 nm The reaction-center chlorophyll a of PS II is called P680
  • 00:24 43.
    Linear Electron Flow
  • 00:04 44.
    Linear electron flow can be broken down into a series of steps A photon hits a pigment and its energy is passed among pigment molecules until it excites P680 An excited electron from P680 is transferred to the primary electron acceptor (we now call it P
  • 00:34 45.
    Linear electron flow can be broken down into a series of steps A photon hits a pigment and its energy is passed among pigment molecules until it excites P680 An excited electron from P680 is transferred to the primary electron acceptor (we now call it P
  • 01:46 46.
    Figure 8.13-5
  • 00:07 47.
    Each electron “falls” down an electron transport chain from the primary electron acceptor of PS II to PS I Energy released by the fall drives the creation of a proton gradient across the thylakoid membrane; diffusion of H (protons) across the membrane dr
  • 00:01 48.
    In PS I (like PS II), transferred light energy excites P700, causing it to lose an electron to an electron acceptor (we now call it P700) P700 accepts an electron passed down from PS II via the electron transport chain
  • 00:02 49.
    Excited electrons “fall” down an electron transport chain from the primary electron acceptor of PS I to the protein ferredoxin (Fd) The electrons are transferred to NADP, reducing it to NADPH, and become available for the reactions of the Calvin cycle Th
  • 00:00 50.
    The energy changes of electrons during linear flow can be represented in a mechanical analogy
  • 00:36 51.
    Figure 8.14
  • 00:00 52.
    The energy changes of electrons during linear flow can be represented in a mechanical analogy
  • 00:00 53.
    Excited electrons “fall” down an electron transport chain from the primary electron acceptor of PS I to the protein ferredoxin (Fd) The electrons are transferred to NADP, reducing it to NADPH, and become available for the reactions of the Calvin cycle Th
  • 00:00 54.
    In PS I (like PS II), transferred light energy excites P700, causing it to lose an electron to an electron acceptor (we now call it P700) P700 accepts an electron passed down from PS II via the electron transport chain
  • 00:00 55.
    Each electron “falls” down an electron transport chain from the primary electron acceptor of PS II to PS I Energy released by the fall drives the creation of a proton gradient across the thylakoid membrane; diffusion of H (protons) across the membrane dr
  • 00:04 56.
    Figure 8.13-5
  • 00:00 57.
    Each electron “falls” down an electron transport chain from the primary electron acceptor of PS II to PS I Energy released by the fall drives the creation of a proton gradient across the thylakoid membrane; diffusion of H (protons) across the membrane dr
  • 00:00 58.
    In PS I (like PS II), transferred light energy excites P700, causing it to lose an electron to an electron acceptor (we now call it P700) P700 accepts an electron passed down from PS II via the electron transport chain
  • 00:00 59.
    Excited electrons “fall” down an electron transport chain from the primary electron acceptor of PS I to the protein ferredoxin (Fd) The electrons are transferred to NADP, reducing it to NADPH, and become available for the reactions of the Calvin cycle Th
  • 00:00 60.
    The energy changes of electrons during linear flow can be represented in a mechanical analogy
  • 00:00 61.
    Figure 8.14
  • 00:01 62.
    A Comparison of Chemiosmosis in Chloroplasts and Mitochondria
  • 00:34 63.
    A Comparison of Chemiosmosis in Chloroplasts and Mitochondria
  • 00:29 64.
    In mitochondria, protons are pumped to the intermembrane space and drive ATP synthesis as they diffuse back into the mitochondrial matrix In chloroplasts, protons are pumped into the thylakoid space and drive ATP synthesis as they diffuse back into the st
  • 00:44 65.
    Figure 8.15
  • 00:50 66.
    ATP and NADPH are produced on the side facing the stroma, where the Calvin cycle takes place In summary, light reactions generate ATP and increase the potential energy of electrons by moving them from H2O to NADPH
  • 00:40 67.
    Figure 8.UN02
  • 01:36 68.
    Figure 8.16
  • 00:19 69.
    Concept 8.3: The Calvin cycle uses the chemical energy of ATP and NADPH to reduce CO2 to sugar
  • 01:52 70.
    Carbon enters the cycle as CO2 and leaves as a sugar named glyceraldehyde 3-phospate (G3P) For net synthesis of one G3P, the cycle must take place three times, fixing three molecules of CO2 The Calvin cycle has three phases Carbon fixation Reduction Rege
  • 00:28 71.
    Phase 1, carbon fixation, involves the incorporation of the CO2 molecules into ribulose bisphosphate (RuBP) using the enzyme rubisco
  • 00:06 72.
    Figure 8.UN03
  • 03:01 73.
    Figure 8.17-3
  • 00:10 74.
    Phase 2, reduction, involves the reduction and phosphorylation of 3-phosphoglycerate to G3P
  • 00:04 75.
    Figure 8.17-3
  • 00:00 76.
    Phase 2, reduction, involves the reduction and phosphorylation of 3-phosphoglycerate to G3P
  • 00:04 77.
    Phase 3, regeneration, involves the rearrangement of G3P to regenerate the initial CO2 receptor, RuBP 3+36, 6+39, 95+4, 4+37, 7+310, 105+5
  • 00:02 78.
    Evolution of Alternative Mechanisms of Carbon Fixation in Hot, Arid Climates
  • 01:16 79.
    Evolution of Alternative Mechanisms of Carbon Fixation in Hot, Arid Climates
  • 01:26 80.
    In most plants (C3 plants), initial fixation of CO2, via rubisco, forms a three-carbon compound (3-phosphoglycerate) In photorespiration, rubisco adds O2 instead of CO2 in the Calvin cycle, producing a two-carbon compound Photorespiration decreases photos
  • 00:03 81.
    Photorespiration may be an evolutionary relic because rubisco first evolved at a time when the atmosphere had far less O2 and more CO2 Photorespiration limits damaging products of light reactions that build up in the absence of the Calvin cycle
  • 00:17 82.
    Photorespiration may be an evolutionary relic because rubisco first evolved at a time when the atmosphere had far less O2 and more CO2 Photorespiration limits damaging products of light reactions that build up in the absence of the Calvin cycle
  • 01:52 83.
    C4 Plants
  • 02:57 84.
    Figure 8.18
  • 00:12 85.
    CAM Plants
  • 00:03 86.
    The Importance of Photosynthesis: A Review
  • 01:39 87.
    The Importance of Photosynthesis: A Review
  • 01:12 88.
    Figure 8.19
  • Index
  • Notes
  • Discuss
  • Fullscreen
photosynthesis
Duration: 53:22, Browse: 587, Update: 2020-08-24
    • 00:09 1.
      8
    • 00:29 2.
      Overview: The Process That Feeds the Biosphere
    • 00:52 3.
      Autotrophs sustain themselves without eating anything derived from other organisms Autotrophs are the producers of the biosphere, producing organic molecules from CO2 and other inorganic molecules Almost all plants are photoautotrophs, using the energy of
    • 00:26 4.
      Figure 8.1
    • 00:59 5.
      Heterotrophs obtain their organic material from other organisms Heterotrophs are the consumers of the biosphere Almost all heterotrophs, including humans, depend on photoautotrophs for food and O2
    • 00:47 6.
      Figure 8.2
    • 01:26 7.
      Concept 8.1: Photosynthesis converts light energy to the chemical energy of food
    • 00:42 8.
      Chloroplasts: The Sites of Photosynthesis in Plants
    • 00:44 9.
      CO2 enters and O2 exits the leaf through microscopic pores called stomata The chlorophyll is in the membranes of thylakoids (connected sacs in the chloroplast); thylakoids may be stacked in columns called grana Chloroplasts also contain stroma, a dense in
    • 00:00 10.
      Figure 8.3
    • 00:43 11.
      Figure 8.3
    • 00:39 12.
      Tracking Atoms Through Photosynthesis: Scientific Inquiry
    • 00:26 13.
      The Splitting of Water
    • 00:35 14.
      Figure 8.4
    • 00:43 15.
      Photosynthesis as a Redox Process
    • 00:19 16.
      Figure 8.UN01
    • 00:49 17.
      The Two Stages of Photosynthesis: A Preview
    • 00:59 18.
      Figure 8.5
    • 00:23 19.
      The Calvin cycle (in the stroma) forms sugar from CO2, using ATP and NADPH The Calvin cycle begins with carbon fixation, incorporating CO2 into organic molecules
    • 00:39 20.
      Concept 8.2: The light reactions convert solar energy to the chemical energy of ATP and NADPH
    • 00:37 21.
      The Nature of Sunlight
    • 00:45 22.
      The electromagnetic spectrum is the entire range of electromagnetic energy, or radiation Visible light consists of wavelengths (including those that drive photosynthesis) that produce colors we can see Light also behaves as though it consists of discrete
    • 01:00 23.
      Figure 8.6
    • 00:43 24.
      Photosynthetic Pigments: The Light Receptors
    • 00:46 25.
      Figure 8.7
    • 00:14 26.
      A spectrophotometer measures a pigment’s ability to absorb various wavelengths This machine sends light through pigments and measures the fraction of light transmitted at each wavelength
    • 01:21 27.
      Figure 8.8
    • 00:10 28.
      An absorption spectrum is a graph plotting a pigment’s light absorption versus wavelength The absorption spectrum of chlorophyll a suggests that violet-blue and red light work best for photosynthesis Accessory pigments include chlorophyll b and a group of
    • 00:22 29.
      Figure 8.8
    • 00:04 30.
      An absorption spectrum is a graph plotting a pigment’s light absorption versus wavelength The absorption spectrum of chlorophyll a suggests that violet-blue and red light work best for photosynthesis Accessory pigments include chlorophyll b and a group of
    • 02:24 31.
      Figure 8.9
    • 00:02 32.
      The action spectrum of photosynthesis was first demonstrated in 1883 by Theodor W. Engelmann In his experiment, he exposed different segments of a filamentous alga to different wavelengths Areas receiving wavelengths favorable to photosynthesis produced e
    • 00:15 33.
      The action spectrum of photosynthesis was first demonstrated in 1883 by Theodor W. Engelmann In his experiment, he exposed different segments of a filamentous alga to different wavelengths Areas receiving wavelengths favorable to photosynthesis produced e
    • 00:14 34.
      Chlorophyll a is the main photosynthetic pigment Accessory pigments, such as chlorophyll b, broaden the spectrum used for photosynthesis A slight structural difference between chlorophyll a and chlorophyll b causes them to absorb slightly different wavele
    • 00:30 35.
      Figure 8.10
    • 00:01 36.
      Excitation of Chlorophyll by Light
    • 00:43 37.
      Excitation of Chlorophyll by Light
    • 01:20 38.
      Figure 8.11
    • 00:01 39.
      A Photosystem: A Reaction-Center Complex Associated with Light-Harvesting Complexes
    • 01:07 40.
      A Photosystem: A Reaction-Center Complex Associated with Light-Harvesting Complexes
    • 01:04 41.
      Figure 8.12
    • 00:36 42.
      There are two types of photosystems in the thylakoid membrane Photosystem II (PS II) functions first (the numbers reflect order of discovery) and is best at absorbing a wavelength of 680 nm The reaction-center chlorophyll a of PS II is called P680
    • 00:24 43.
      Linear Electron Flow
    • 00:04 44.
      Linear electron flow can be broken down into a series of steps A photon hits a pigment and its energy is passed among pigment molecules until it excites P680 An excited electron from P680 is transferred to the primary electron acceptor (we now call it P
    • 00:34 45.
      Linear electron flow can be broken down into a series of steps A photon hits a pigment and its energy is passed among pigment molecules until it excites P680 An excited electron from P680 is transferred to the primary electron acceptor (we now call it P
    • 01:46 46.
      Figure 8.13-5
    • 00:07 47.
      Each electron “falls” down an electron transport chain from the primary electron acceptor of PS II to PS I Energy released by the fall drives the creation of a proton gradient across the thylakoid membrane; diffusion of H (protons) across the membrane dr
    • 00:01 48.
      In PS I (like PS II), transferred light energy excites P700, causing it to lose an electron to an electron acceptor (we now call it P700) P700 accepts an electron passed down from PS II via the electron transport chain
    • 00:02 49.
      Excited electrons “fall” down an electron transport chain from the primary electron acceptor of PS I to the protein ferredoxin (Fd) The electrons are transferred to NADP, reducing it to NADPH, and become available for the reactions of the Calvin cycle Th
    • 00:00 50.
      The energy changes of electrons during linear flow can be represented in a mechanical analogy
    • 00:36 51.
      Figure 8.14
    • 00:00 52.
      The energy changes of electrons during linear flow can be represented in a mechanical analogy
    • 00:00 53.
      Excited electrons “fall” down an electron transport chain from the primary electron acceptor of PS I to the protein ferredoxin (Fd) The electrons are transferred to NADP, reducing it to NADPH, and become available for the reactions of the Calvin cycle Th
    • 00:00 54.
      In PS I (like PS II), transferred light energy excites P700, causing it to lose an electron to an electron acceptor (we now call it P700) P700 accepts an electron passed down from PS II via the electron transport chain
    • 00:00 55.
      Each electron “falls” down an electron transport chain from the primary electron acceptor of PS II to PS I Energy released by the fall drives the creation of a proton gradient across the thylakoid membrane; diffusion of H (protons) across the membrane dr
    • 00:04 56.
      Figure 8.13-5
    • 00:00 57.
      Each electron “falls” down an electron transport chain from the primary electron acceptor of PS II to PS I Energy released by the fall drives the creation of a proton gradient across the thylakoid membrane; diffusion of H (protons) across the membrane dr
    • 00:00 58.
      In PS I (like PS II), transferred light energy excites P700, causing it to lose an electron to an electron acceptor (we now call it P700) P700 accepts an electron passed down from PS II via the electron transport chain
    • 00:00 59.
      Excited electrons “fall” down an electron transport chain from the primary electron acceptor of PS I to the protein ferredoxin (Fd) The electrons are transferred to NADP, reducing it to NADPH, and become available for the reactions of the Calvin cycle Th
    • 00:00 60.
      The energy changes of electrons during linear flow can be represented in a mechanical analogy
    • 00:00 61.
      Figure 8.14
    • 00:01 62.
      A Comparison of Chemiosmosis in Chloroplasts and Mitochondria
    • 00:34 63.
      A Comparison of Chemiosmosis in Chloroplasts and Mitochondria
    • 00:29 64.
      In mitochondria, protons are pumped to the intermembrane space and drive ATP synthesis as they diffuse back into the mitochondrial matrix In chloroplasts, protons are pumped into the thylakoid space and drive ATP synthesis as they diffuse back into the st
    • 00:44 65.
      Figure 8.15
    • 00:50 66.
      ATP and NADPH are produced on the side facing the stroma, where the Calvin cycle takes place In summary, light reactions generate ATP and increase the potential energy of electrons by moving them from H2O to NADPH
    • 00:40 67.
      Figure 8.UN02
    • 01:36 68.
      Figure 8.16
    • 00:19 69.
      Concept 8.3: The Calvin cycle uses the chemical energy of ATP and NADPH to reduce CO2 to sugar
    • 01:52 70.
      Carbon enters the cycle as CO2 and leaves as a sugar named glyceraldehyde 3-phospate (G3P) For net synthesis of one G3P, the cycle must take place three times, fixing three molecules of CO2 The Calvin cycle has three phases Carbon fixation Reduction Rege
    • 00:28 71.
      Phase 1, carbon fixation, involves the incorporation of the CO2 molecules into ribulose bisphosphate (RuBP) using the enzyme rubisco
    • 00:06 72.
      Figure 8.UN03
    • 03:01 73.
      Figure 8.17-3
    • 00:10 74.
      Phase 2, reduction, involves the reduction and phosphorylation of 3-phosphoglycerate to G3P
    • 00:04 75.
      Figure 8.17-3
    • 00:00 76.
      Phase 2, reduction, involves the reduction and phosphorylation of 3-phosphoglycerate to G3P
    • 00:04 77.
      Phase 3, regeneration, involves the rearrangement of G3P to regenerate the initial CO2 receptor, RuBP 3+36, 6+39, 95+4, 4+37, 7+310, 105+5
    • 00:02 78.
      Evolution of Alternative Mechanisms of Carbon Fixation in Hot, Arid Climates
    • 01:16 79.
      Evolution of Alternative Mechanisms of Carbon Fixation in Hot, Arid Climates
    • 01:26 80.
      In most plants (C3 plants), initial fixation of CO2, via rubisco, forms a three-carbon compound (3-phosphoglycerate) In photorespiration, rubisco adds O2 instead of CO2 in the Calvin cycle, producing a two-carbon compound Photorespiration decreases photos
    • 00:03 81.
      Photorespiration may be an evolutionary relic because rubisco first evolved at a time when the atmosphere had far less O2 and more CO2 Photorespiration limits damaging products of light reactions that build up in the absence of the Calvin cycle
    • 00:17 82.
      Photorespiration may be an evolutionary relic because rubisco first evolved at a time when the atmosphere had far less O2 and more CO2 Photorespiration limits damaging products of light reactions that build up in the absence of the Calvin cycle
    • 01:52 83.
      C4 Plants
    • 02:57 84.
      Figure 8.18
    • 00:12 85.
      CAM Plants
    • 00:03 86.
      The Importance of Photosynthesis: A Review
    • 01:39 87.
      The Importance of Photosynthesis: A Review
    • 01:12 88.
      Figure 8.19
    Location
    Folder name
    普通生物學
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    王姿文
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    生科系
    Create
    2016-01-23 09:21:51
    Update
    2020-08-24 23:37:57
    Browse
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    Duration
    53:22