1 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Glucose provides the energy and carbon needed to synthesize other plant material. Jan Baptisa van Helmont (1648)  "...I took an earthenware vessel, placed in it 200 pounds of soil dried in an oven, soaked this with rainwater, and planted in it a willow branch weighing 5 pounds. At the end of five years, the tree grown from it weighed 169 pounds and about 3 ounces. Now, the earthenware vessel was always moistened (when necessary) only with rainwater or distilled water, and it was large enough and embedded in the ground, and, lest dust flying be mixed with the soil, an iron plate coated with tin and pierced by many holes covered the rim of the vessel. I did not compute the weight of the fallen leaves of the four autumns. Finally, I dried the soil in the vessel again, and the same 200 pounds were found, less about 2 ounces. Therefore 169 pounds of wood, bark, and root had arisen from water only.”  6CO 2 + 6H 2 O + Energy  C 6 H 12 O 6 + 6O 2

2 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Jan Baptisa van Helmont (1648)  "...I took an earthenware vessel, placed in it 200 pounds of soil dried in an oven, soaked this with rainwater, and planted in it a willow branch weighing 5 pounds. At the end of five years, the tree grown from it weighed 169 pounds and about 3 ounces. Now, the earthenware vessel was always moistened (when necessary) only with rainwater or distilled water, and it was large enough and embedded in the ground, and, lest dust flying be mixed with the soil, an iron plate coated with tin and pierced by many holes covered the rim of the vessel. I did not compute the weight of the fallen leaves of the four autumns. Finally, I dried the soil in the vessel again, and the same 200 pounds were found, less about 2 ounces. Therefore 169 pounds of wood, bark, and root had arisen from water only.”  6CO 2 + 6H 2 O + Energy  C 6 H 12 O 6 + 6O 2 As can be seen from the equation for photosynthesis, the wood, bark, and root arose from water and carbon dioxide.

3 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Photosynthesis

4 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Before you start…  There are 83 slides in this presentation.  Some of the slide navigation functions require full screen mode. Select “Browse” or “View” from the menu above, then select “Full Screen”.  Powerpoint Version: Use the arrow keys (  or  ) to advance the slides or go backwards. The left mouse button also advances slides. You can click anywhere on the screen. If you know the slide number, you can enter the number and press Enter to go directly to that slide. The slide number is at the bottom left of most slides. Press “Esc” to end the program.  Internet Explorer Version: Click the slide name at the left side of the screen or use the arrow buttons at the bottom of the screen on either side of the slide counter.  A menu appears at the bottom of most of the slides. You can use this to go to the topics shown.

5 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Light Click on an image to view the slide.

Red Blue Wavelength 700 nm 470 nm Light travels in waves. The color of light is determined by its wavelength. The red light shown below has a wavelength of 700 nm. Notice that blue light has a shorter wavelength. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

7 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Electromagnetic Spectrum Visible light is only a part of the electromagnetic spectrum m 10 3 m nanometers Visible light Gamma rays X-raysUVInfraredMicrowavesRadio waves

8 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Electromagnetic Spectrum m 10 3 m nanometers Visible light Gamma rays X-raysUVInfraredMicrowavesRadio waves The numbers on this chart are wavelength.

9 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Electromagnetic Spectrum m 10 3 m nanometers Visible light Gamma rays X-raysUVInfraredMicrowavesRadio waves The spectrum shown below fits into the small space shown on the line.

10 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Photosynthetic Pigments Click on an image to view the slide.

11 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Photosynthetic Pigments Photon Plants have pigment molecules that contain atoms that become energized when they are struck by photons of light. Energized electrons move further from the nucleus. Light behaves as if it is composed of units or packets called photons.

12 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Photosynthetic Pigments Heat or light The energized molecule can transfer the energy to another atom or molecule or release it in the form of heat or light.

13 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Photosynthetic Pigments When the energy is released, the electron returns to a location closer to the nucleus. Heat or light

What color is best?  In this experiment, a prism is used to produce a gradient of light that ranges from red to blue. The large cell is a photosynthetic alga called Spirogyra seen magnified under a microscope. The spiral-shaped green structure is its chloroplast.  The bacteria (represented by dots) are aerobic, that is, they require oxygen.  The slide was initially prepared so that there was no oxygen present in the water surrounding the alga.  Photosynthesis produces oxygen and the bacteria congregate in areas where the most oxygen is produced, thus, where the rate of photosynthesis is highest. Blue and red light therefore produce the highest rate of photosynthesis. Chloroplast of Spirogyra Bacteria Colors produced by a prism LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Absorption Spectrum absorption Chlorophyll a Chlorophyll b Carotenoids Wavelength This graph shows the color of light absorbed by three different kinds of photosynthetic pigments. Notice that they do not absorb light that is in the green to yellow range. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

16 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Overview Click on an image to view the slide.

17 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Two Kinds of Reactions  The reactions of photosynthesis can be divided into two main categories: »The light reactions require light. »The light-independent reactions occur either in the light or in the dark.  As you view the rest of these slides, keep in mind that the “goal” of photosynthesis is to synthesize glucose. »Carbon dioxide is reduced to glucose (see equation below). [Be sure that you know what is meant by “reduced” before you go on.] »The electrons needed for this reduction come from water. »The energy needed for this reduction comes from light. »The equation is: Energy + 6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2

Light Reactions light reactions During photosynthesis, CO 2 will be reduced (gain electrons) to form glucose. The electrons needed to reduce CO 2 are temporarily carried by NADPH. light ATPNADPH LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Light Reactions H2OH2OO2O2 light reactions light Recall that hydrogen atoms can be used to carry electrons. NADPH gets its electrons from water. The oxygen is not used. ATPNADPH LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Light-Independent Reactions light-independent reactions (Calvin cycle) C 6 H 12 O 6 C0 2 The reduction of CO 2 to glucose occurs in the light-independent reactions. H2OH2OO2O2 light reactions light ATPNADPH LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Summary of Photosynthesis light-independent reactions (Calvin cycle) C 6 H 12 O 6 C0 2 H2OH2OO2O2 light reactions ATPNADPH light LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return ADP NADP + This slide summarizes photosynthesis. 6CO 2 + 6H 2 O + E  C 6 H 12 O 6 + 6O 2

22 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Chloroplast Structure Click on an image to view the slide.

23 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Elodea leaf X 400 The small green structures within the cells of this plant are chloroplasts. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

24 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Chloroplast Structure Thylakoids Double membrane Stroma In order to understand the reactions of photosynthesis, it will be helpful to review the structure of a chloroplast. It contains disk- shaped structures called thylakoids. The area outside the disks is called the stroma.

25 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Photosystem II

Summary of Photosynthesis light-independent reactions (Calvin cycle) C 6 H 12 O 6 C0 2 H2OH2OO2O2 light reactions ATPNADPH light LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return ADP NADP + The next several slides will examine the light reactions of photosynthesis.

Antenna Thylakoid membrane This drawing shows a magnified view of a part of a thylakoid. The green area is the thylakoid and the blue area is the stroma of the chloroplast. Photosynthetic pigments embedded within the membrane form a unit called an antenna. Stroma Photosynthetic pigments such as chlorophyll A, chlorophyll B and carotinoids. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Reaction Center, Electron Acceptor Thylakoid membrane A pigment molecule within the antenna absorbs a photon of light energy. The energy from that pigment molecule is passed to neighboring pigment molecules and eventually makes its way to pigment molecule called the reaction center. When the reaction center molecule becomes excited (energized), it loses an electron to an electron acceptor. Reaction center Electron acceptor Light energy LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Reaction Center, Electron Acceptor Thylakoid membrane As a result of gaining an electron (reduction), the electron acceptor becomes a high-energy molecule. Remember - its energy came from light. To understand this transfer of energy, recall that oxidation is the loss of an electron and the loss of energy. Reduction is the gain of an electron and energy. Energy is transferred with the electron. Reaction center Electron acceptor Light energy LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Antenna, Photosystem Antenna Reaction center Electron acceptor Photosystem Thylakoid membrane The antenna and electron acceptor are called a photosystem. There are two kinds of photosystems in plants called photosystem I and photosystem II. Photosystem I is sometimes called P 700 and photosystem II is sometimes P 680. The 680 and 700 designations refer to the wavelength of light that they absorb best. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Antenna, Photosystem Antenna Reaction center Electron acceptor Photosystem Thylakoid membrane In the diagrams that follow, the antenna will be drawn as a single green circle and the electron acceptor as a single red circle. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

32 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Electron Transport System Click here to review the electron transport system of the mitochondrion.

Electron Transport System Stroma Light Energy Chloroplast Photosystem IIPhotosystem I The three blue circles represent the electron transport system. They are proteins embedded within the thylakoid membrane. The first protein receives the electron (and energy) from the electron acceptor. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Electron Transport System H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ Light Energy Chloroplast As a result of gaining an electron (reduction), the first carrier of the electron transport system gains energy. It uses some of the energy to pump H + into the thylakoid. H+H+ H+H+ ThylakoidsStroma LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Electron Transport System H+H+ H+H+ H+H+ H+H+ H+H+ Light Energy Chloroplast The carrier then passes the electron to the next carrier. Because it used some energy to pump H +, it has less energy (reducing capability) to pass to the next H + pump. H+H+ H+H+ ThylakoidsStroma LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Electron Transport System H+H+ H+H+ H+H+ H+H+ H+H+ Light Energy Chloroplast This carrier uses some of the remainder of the energy to pump more H + into the thylakoid. H+H+ H+H+ H+H+ ThylakoidsStroma LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Electron Transport System H+H+ H+H+ H+H+ H+H+ H+H+ Light Energy Chloroplast The electron is passed to the next carrier which also pumps H +. H+H+ H+H+ H+H+ ThylakoidsStroma LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Electron Transport System H+H+ H+H+ H+H+ H+H+ H+H+ Light Energy Chloroplast The electron transport system functions to create a concentration gradient of H + inside the thylakoid. H+H+ H+H+ H+H+ ThylakoidsStroma LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Photophosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ Light Energy Chloroplast H+H+ H+H+ H+H+ ATP ADP + P i ThylakoidsStroma The concentration gradient of H + is used to synthesize ATP. ATP is produced from ADP and P i when hydrogen ions pass out of the thylakoid through ATP synthase. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Photophosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ Light Energy Chloroplast H+H+ H+H+ H+H+ ThylakoidsStroma ATP ADP + P i This method of synthesizing ATP by using a H + gradient in the thylakoid is called photophosphorylation. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

41 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Photosystem I

H+H+ H+H+ H+H+ H+H+ H+H+ ThylakoidsStroma Light Energy Chloroplast H+H+ H+H+ H+H+ At this point, the electron has little reducing capability (little energy is left). It is passed to the P 700 antenna. ATP ADP + P i LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

P 700 Antenna H+H+ H+H+ H+H+ H+H+ H+H+ ThylakoidsStroma Light Energy Chloroplast H+H+ H+H+ H+H+ A pigment molecule in the P 700 antenna absorbs a photon of solar energy. The energy from that molecule is passed to neighboring molecules within the antenna. The energy is eventually passed to the reaction center of this antenna. ATP ADP + P i LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Electron Acceptor H+H+ H+H+ H+H+ H+H+ H+H+ ThylakoidsStroma Light Energy Chloroplast H+H+ H+H+ H+H+ As a result of being energized, the P 700 reaction center loses the electron to an electron acceptor. ATP ADP + P i LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

NADP + H+H+ H+H+ H+H+ H+H+ H+H+ ThylakoidsStroma Light Energy Chloroplast H+H+ H+H+ H+H+ The acceptor passes it to NADP +, which becomes reduced to NADPH. According to the following equation, NADP + has the capacity to carry two electrons. NADP + + 2e - + H +  NADPH NADP + + H + NADPH ATP ADP + P i LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Splitting H 2 O H+H+ H+H+ H+H+ H+H+ H+H+ ThylakoidsStroma Light Energy Chloroplast H+H+ H+H+ H+H+ NADP + + H + NADPH The electron that was initially lost by photosystem II (P 680 ) must be replaced. ATP ADP + P i LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Splitting H 2 O H+H+ H+H+ H+H+ H+H+ H+H+ ThylakoidsStroma Light Energy Chloroplast H+H+ H+H+ H+H+ NADP + + H + NADPH H 2 O  2e - + 2H + + ½ O 2 A hydrogen atom contains one electron (e - ) and one proton (H + ). The two hydrogen atoms in a water molecule can therefore be used to produce 2e - and 2H +. ATP ADP + P i LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Summary of Light Reactions e - acceptor light NADPH NADP + electron transport system ATP H 2 O  2e - + 2H + + O e - acceptor P 680 antenna complex P 700 antenna complex This diagram traces the path followed by an electron during the light reactions. The path is indicated by red arrows and letters. The high- energy parts of the pathway are drawn near the top of the diagram. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Calvin Cycle H+H+ H+H+ H+H+ H+H+ H+H+ ThylakoidsStroma Light Energy Chloroplast H+H+ H+H+ H+H+ NADP + + H + NADPH H 2 O  2e - + 2H + + ½ O 2 glucose CO 2 Calvin Cycle The next several slides show how the products of the light reactions (ATP and NADPH) are used to reduce CO 2 to carbohydrate in the Calvin cycle. ATP ADP + P i LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Calvin Cycle H+H+ H+H+ H+H+ H+H+ H+H+ ThylakoidsStroma Light Energy Chloroplast H+H+ H+H+ H+H+ NADP + + H + NADPH H 2 O  2e - + 2H + + ½ O 2 glucose CO 2 Calvin Cycle The reactions of the Calvin cycle occur in the stroma of the chloroplast. ATP ADP + P i LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

51 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Calvin Cycle

Summary of Photosynthesis ADP NADP + light-independent reactions (Calvin cycle) C 6 H 12 O 6 C0 2 H2OH2OO2O2 light reactions ATPNADPH light LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

53 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return CO 2 Fixation  CO 2 fixation refers to bonding CO 2 to an organic molecule to make a larger molecule.  C 5 + CO 2  C 6 “C 5 ” is an abbreviation that means that this molecule has 5 carbon atoms. The oxygen and hydrogen atoms are not written.

RuBP Carboxylase (rubisco) 6 C-C-C-C-C 6 CO 2 6 C-C-C-C-C-C CO 2 Fixation CO 2 fixation refers to bonding CO 2 to an organic molecule to make a larger molecule. Each CO 2 is bonded to ribulose biphosphate (RuBP). C 5 + CO 2  C 6 The enzyme that catalyzes this reaction is ribulose biphosphate carboxylase (rubisco). LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

C 3 Photosynthesis – Calvin Cycle Each of these 6-carbon compounds splits to form two 3-carbon compounds called phosphoglycerate. PGARuBP Carboxylase (rubisco) 6 C-C-C-C-C 6 CO 2 6 C-C-C-C-C-C 12 C-C-C LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

The two molecules of PGA are reduced to form PGAL (phosphoglyceraldehyde). PGA PGAL RuBP Carboxylase (rubisco) 12 C-C-C 6 C-C-C-C-C 6 CO 2 6 C-C-C-C-C-C 12 C-C-C LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Calvin Cycle

PGA PGAL RuBP Carboxylase (rubisco) 12 C-C-C 6 C-C-C-C-C 6 CO 2 6 C-C-C-C-C-C 12 C-C-C 12 ATP 12 NADPH 12 NADP + 12 ADP + P LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Calvin Cycle

PGA PGAL Glucose RuBP Carboxylase (rubisco) 12 C-C-C C-C-C-C-C-C 6 C-C-C-C-C 6 CO 2 6 C-C-C-C-C-C 12 C-C-C 10 C-C-C 6 ADP + P 6 ATP 12 ATP 12 NADPH 12 NADP + 12 ADP + P Two of the PGAL are used to form glucose phosphate, then glucose. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Calvin Cycle

PGA PGAL Glucose RuBP Carboxylase (rubisco) 12 C-C-C C-C-C-C-C-C 6 C-C-C-C-C 6 CO 2 6 C-C-C-C-C-C 12 C-C-C 10 C-C-C 6 ADP + P 6 ATP 12 ATP 12 NADPH 12 NADP + 12 ADP + P The remaining 10 PGAL are rearranged to form 6 RuBP. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Calvin Cycle

PGA PGAL Glucose RuBP Carboxylase (rubisco) 12 C-C-C C-C-C-C-C-C 6 C-C-C-C-C 6 CO 2 6 C-C-C-C-C-C 12 C-C-C 10 C-C-C 6 ADP + P 6 ATP 12 ATP 12 NADPH 12 NADP + 12 ADP + P This process requires energy in the form of ATP. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Calvin Cycle

Summary of Photosynthesis ADP NADP + C 6 H 12 O 6 C0 2 H2OH2OO2O2 Light reactions ATPNADPH light Light-independent reactions LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

62 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return End of Part 1  Please go back and review these slides and the information on photosynthesis before continuing.  When you are ready to resume, select “Photorespiration” on the menu.

63 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Photorespiration Begin this topic with the next slide.

CO 2 Fixation RuBP Carboxylase (rubisco) 12 C-C-C C-C-C-C-C-C 6 C-C-C-C-C 6 C-C-C-C-C-C 12 C-C-C 6 CO 2 10 C-C-C LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

65 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return mesophyll cells vein bundle-sheath cells Cross Section of a C 3 Leaf stoma Stomata (singular stoma) are microscopic openings on the undersurface of leaves that allow gas exchange and water evaporation from inside the leaf. Because dehydration can be a serious problem, the stomata close when the plant is under water stress. When closed, CO 2 needed for the Calvin cycle cannot enter.

If CO 2 is low RuBP 6 C-C-C-C-C 6 C-C-C-C-C-C 6 CO 2 RUBISCO CO 2 When the concentration of CO 2 is low (red above), oxygen will bind to the active site of RUBISCO. When oxygen is bound to RUBISCO, RuBP is broken down and CO 2 is released. This wastes energy and is of no use to the plant. It is called photorespiration because oxygen is taken up and CO 2 is released. O2O2 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

67 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Cross Section of a C 3 Leaf Photosynthesis occurs within the mesophyll cells in C 3 plants, which form a dense layer on the upper surface of the leaf and a spongy layer on the lower surface. Bundle-sheath cells surrounding the veins are not photosynthetic. mesophyll cells vein bundle-sheath cells stoma

68 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return C 4 Plants

69 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Cross Section of a C 4 Leaf vein mesophyll cells bundle-sheath cells stoma

70 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return CO 2 Fixation in C 4 Plants CO 2 C3C3 C4C4 Calvin cycle mesophyll cells bundle sheath cells  CO 2 fixation occurs in mesophyll cells

71 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return CO 2 Fixation in C 4 Plants CO 2 C3C3 C4C4 Calvin cycle C3C3 CO 2  CO 2 fixation occurs in mesophyll cells  Calvin cycle occurs in bundle sheath cells

72 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Review Exercises

73 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Review – ATP A D B C Identify components A through D. ADP + P i ATP Energy

74 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Review – NADPH NADP + NADPH + H + Energy + 2H A D B C

light reactions A BC G F D E J Identify: ADP + P i ATP Calvin cycle CO 2 glucose phosphate light NADP + NADPH oxygen water Review – Summary of Photosynthesis HI LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

light reactions light-independent reactions (Calvin cycle) light ATPNADPH C-C-C-C-C-C C0 2 ADP NADP + H 2 O  2H + 2e - + O LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Review – Chloroplast Structure  Where do the light reactions occur?  Where do the light-independent reactions occur?

Review – Calvin Cycle G 12 E 6 B 6 A 6 C 12 D 10 F LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return How many carbon atoms?

78 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Review – Calvin Cycle 12 E G 6 B 6 A 6 C 12 D 10 F 12 H 12 I 12 J 12 K 6L 6M Identify each component.

79 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Review – Inputs and Products Inputs Produced Light ReactionsLight-Independent Reactions Fill in the Boxes below.

80 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Review – Inputs and Products Inputs Produced Light ReactionsLight-Independent Reactions light, ADP, NADP +, H 2 O Fill in the Boxes below.

81 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Review – Inputs and Products Inputs Produced Light ReactionsLight-Independent Reactions light, ADP, NADP +, H 2 O ATP, NADPH, O 2, H + Fill in the Boxes below.

82 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Review – Inputs and Products Inputs Produced Light ReactionsLight-Independent Reactions light, ADP, NADP +, H 2 O ATP, NADPH, CO 2 ATP, NADPH, O 2, H + Fill in the Boxes below.

83 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Review – Inputs and Products Inputs Produced Light ReactionsLight-Independent Reactions light, ADP, NADP +, H 2 O ATP, NADPH, CO 2 ATP, NADPH, O 2, H + glucose, ADP, NADP + Fill in the Boxes below.

84 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return The End

85 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Mitochondrion Structure Cristae Matrix Intermembrane Space  This drawing shows a mitochondrion cut lengthwise to reveal its internal components.

Oxidative Phosphorylation inside outside intermembrane space These red dots represent proteins in the electron transport system LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Oxidative Phosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ NADH NADH and FADH 2 from cellular respiration bring electrons to the electron transport system. e-e- LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Oxidative Phosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ When a carrier is reduced, some of the energy that is gained as a result of that reduction is used to pump hydrogen ions across the membrane into the intermembrane space. e-e- LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Oxidative Phosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ The electron is then passed to another carrier. e-e- LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Oxidative Phosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ As before, some of the energy gained by the next carrier as a result of reduction is used to pump hydrogen ions into the intermembrane space. e-e- LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Oxidative Phosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ e-e- LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Oxidative Phosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ e-e- LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Oxidative Phosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ Eventually, a concentration gradient of hydrogen ions is established in the intermembrane space (green on the diagram). e-e- LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Oxidative Phosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ The last carrier must get rid of the electron. It passes it to oxygen to form water (next slide). e-e- LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Oxidative Phosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ 2H + + 2e - + 1/2 O 2  H 2 O Note that e - + H +  H Two electrons are required to form one molecule of water. The process therefore happens twice for each water molecule. LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Oxidative Phosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ ATP synthase produces ATP by phosphorylating ADP. The energy comes from hydrogen ions forcing their way into the matrix as they pass through the ATP synthase (due to osmotic pressure). ATP ADP + P i H+ LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

Summary of Oxidative Phosphorylation H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ NADH H+H+ H+H+ H+H+ 2H + + 2e - + 1/2 O 2  H 2 O ADP + P i H+ ATP LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return

98 LightLight | Pigments | Overview | Chloroplast | Photosystem II | Electron Transport System | Photosystem I | Calvin Cycle | Photorespiration | C 4 plants | Review |PigmentsOverviewChloroplastPhotosystem IIElectron Transport SystemPhotosystem ICalvin CyclePhotorespirationC 4 plantsReview Return Return Button Click here to return to electron transport in the chloroplast