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Photosynthesis Life Is Solar Powered!

Photosynthesis Life Is Solar Powered!. What Would Plants Look Like On Alien Planets?. Why Would They Look Different?. Different Stars Give off Different types of light or Electromagnetic Waves

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Photosynthesis Life Is Solar Powered!

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  1. PhotosynthesisLife Is Solar Powered!

  2. What Would Plants Look Like On Alien Planets?

  3. Why Would They Look Different? • Different Stars Give off Different types of light or Electromagnetic Waves • The color of plants depends on the spectrum of the star’s light, which astronomers can easily observe. (Our Sun is a type “G” star.)

  4. Anatomy of a Wave • Wavelength • Is the distance between the crests of waves • Determines the type of electromagnetic energy

  5. Electromagnetic Spectrum • Is the entire range of electromagnetic energy, or radiation • The longer the wavelength the lower the energy associated with the wave.

  6. Visible Light • Light is a form of electromagnetic energy, which travels in waves • When white light passes through a prism the individual wavelengths are separated out.

  7. Visible Light Spectrum • Light travels in waves • Light is a form of radiant energy • Radiant energy is made of tiny packets of energy called photons • The red end of the spectrum has the lowest energy (longer wavelength) while the blue end is the highest energy (shorter wavelength). • The order of visible light is ROY-G-BIV • This is the same order you will see in a rainbow b/c water droplets in the air act as tiny prisms

  8. Chloroplast – Where the Magic Happens! + H2O CO2 Energy ATP and NADPH2 Which splits water Light is Adsorbed By Chlorophyll Calvin Cycle ADP NADP Chloroplast Used Energy and is recycled. O2 + C6H12O6 Light Reaction Dark Reaction 6 CO2 + 12 H2O + Light energy  C6H12O6 + 6 O2 + 6 H2 O

  9. Light Reflected Light Chloroplast Absorbed light Granum Transmitted light Figure 10.7 Light Options When It Strikes A Leaf • Reflect – a small amount of light is reflected off of the leaf. Most leaves reflect the color green, which means that it absorbs all of the other colors or wavelengths. • Absorbed – most of the light is absorbed by plants providing the energy needed for the production of Glucose (photosynthesis) • Transmitted – some light passes through the leaf

  10. Photosynthesis Overview Concept Map Photosynthesis includes Light independent reactions Light dependent reactions occurs in uses uses occur in Light Energy Thylakoid membranes ATP Stroma NADPH to produce to produce of ATP NADPH O2 Chloroplasts Glucose

  11. Leaf cross section Vein Mesophyll CO2 O2 Stomata Figure 10.3 Anatomy of a Leaf

  12. Chloroplast

  13. Mesophyll Chloroplast 5 µm Outer membrane Intermembrane space Thylakoid Thylakoid space Granum Stroma Inner membrane 1 µm Chloroplast • Are located within the palisade layer of the leaf • Stacks of membrane sacs called Thylakoids • Contain pigments on the surface • Pigments absorb certain wavelenghts of light • A Stack of Thylakoids is called a Granum

  14. Pigments • Are molecules that absorb light • Chlorophyll, a green pigment, is the primary absorber for photosynthesis • There are two types of cholorophyll • Chlorophyll a • Chlorophyll b • Carotenoids, yellow & orange pigments, are those that produce fall colors. Lots of Vitamin A for your eyes! • Chlorophyll is so abundant that the other pigments are not visible so the plant is green…Then why do leaves change color in the fall?

  15. Color Change • In the fall when the temperature drops plants stop making Chrlorophyll and the Carotenoids and other pigments are left over (that’s why leaves change color in the fall).

  16. Three different experiments helped reveal which wavelengths of light are photosynthetically important. The results are shown below. EXPERIMENT RESULTS Chlorophyll a Chlorophyll b Absorption of light by chloroplast pigments Carotenoids Wavelength of light (nm) (a) Absorption spectra. The three curves show the wavelengths of light best absorbed by three types of chloroplast pigments. Figure 10.9 • The absorption spectra of three types of pigments in chloroplasts

  17. Rate of photosynthesis (measured by O2 release) (b) Action spectrum. This graph plots the rate of photosynthesis versus wavelength. The resulting action spectrum resembles the absorption spectrum for chlorophyll a but does not match exactly (see part a). This is partly due to the absorption of light by accessory pigments such as chlorophyll b and carotenoids. • The action spectrum of a pigment • Profiles the relative effectiveness of different wavelengths of radiation in driving photosynthesis

  18. Aerobic bacteria Filament of alga 500 600 700 400 (c) Engelmann‘s experiment. In 1883, Theodor W. Engelmann illuminated a filamentous alga with light that had been passed through a prism, exposing different segments of the alga to different wavelengths. He used aerobic bacteria, which concentrate near an oxygen source, to determine which segments of the alga were releasing the most O2 and thus photosynthesizing most. Bacteria congregated in greatest numbers around the parts of the alga illuminated with violet-blue or red light. Notice the close match of the bacterial distribution to the action spectrum in part b. Light in the violet-blue and red portions of the spectrum are most effective in driving photosynthesis. CONCLUSION • The action spectrum for photosynthesis • Was first demonstrated by Theodor W. Engelmann

  19. Absorption of chlorophylls a and b at various wavelengths in the visible light spectrum

  20. Pigment • Molecules that absorb specific wavelengths of light • Chlorophyll absorbs reds & blues and reflects green • Xanthophyll absorbs red, blues, greens & reflects yellow • Carotenoids reflect orange

  21. Chlorophyll • Green pigment in plants • Traps sun’s energy • Sunlight energizes electron in chlorophyll

  22. PHOTOSYNTHESIS • Comes from Greek Word “photo” meaning “Light” and “syntithenai” meaning “to put together” • Photosynthesis puts together sugar molecules using water, carbon dioxide, & energy from light.

  23. Happens in two phases • Light-Dependent Reaction • Converts light energy into chemical energy • Light-Independent Reaction • Produces simple sugars (glucose) • General Equation • 6 CO2 + 6 H2O  C6H12O6 + 6 O2

  24. First Phase • Requires Light = Light Dependent Reaction • Sun’s energy energizes an electron in chlorophyll molecule • Electron is passed to nearby protein molecules in the thylakoid membrane of the chloroplast

  25. Excited state e– Heat Energy of election Photon (fluorescence) Ground state Chlorophyll molecule Photon Figure 10.11 A Excitation of Chlorophyll by Light • When a pigment absorbs light • It goes from a ground state to an excited state, which is unstable

  26. Two Photosystems • Photosystem II: Clusters of pigments boost e- by absorbing light w/ wavelength of ~680 nm • Photosystem I: Clusters boost e- by absorbing light w/ wavelength of ~760 nm. • Reaction Center: Both PS have it. Energy is passed to a special Chlorophyll a molecule which boosts an e-

  27. e– ATP e– e– NADPH e– e– e– Mill makes ATP Photon e– Photon Photosystem I Photosystem II Figure 10.14  • A mechanical analogy for the light reactions

  28. ATP • Adenosine Triphosphate • Stores energy in high energy bonds between phosphates

  29. NADPH • Made from NADP+; electrons and hydrogen ions • Made during light reaction • Stores high energy electrons for use during light-Independent reaction (Calvin Cycle)

  30. H2O CO2 Light NADP  ADP + P LIGHT REACTIONS CALVIN CYCLE ATP NADPH Chloroplast [CH2O] (sugar) O2 Figure 10.5

  31. PART II • LIGHT INDEPENDENT REACTION • Also called the Calvin Cycle • No Light Required • Takes place in the stroma of the chloroplast • Takes carbon dioxide & converts into sugar • It is a cycle because it ends with a chemical used in the first step

  32. Begins & Ends • The Calvin Cycle begins with the products of the light reaction. • (the Calvin Cycle uses ATP & NADPH) • CO2 is added and ends in the production of sugar (GLUCOSE) • Formula: C6H12O6

  33. H2O Input CO2 Light 3 (Entering one at a time) NADP+ CO2 ADP CALVINCYCLE LIGHTREACTION ATP NADPH Rubisco O2 [CH2O] (sugar) 3 P P Short-livedintermediate P 6 3 P P Ribulose bisphosphate(RuBP) 3-Phosphoglycerate 6 ATP 6 ADP CALVIN CYCLE 3 ADP 6 P P 3 ATP 1,3-Bisphoglycerate 6 NADPH 6 NADPH+ 6 P P 5 (G3P) 6 P Glyceraldehyde-3-phosphate (G3P) P 1 Glucose andother organiccompounds G3P(a sugar)Output Figure 10.18 • The Calvin cycle Phase 1: Carbon fixation Phase 3:Regeneration ofthe CO2 acceptor(RuBP) Phase 2:Reduction

  34. Chloroplast – Where the Magic Happens! + H2O CO2 Energy ATP and NADPH2 Which splits water Light is Adsorbed By Chlorophyll Calvin Cycle ADP NADP Chloroplast Used Energy and is recycled. O2 + C6H12O6 Light Reaction Dark Reaction 6 CO2 + 12 H2O + Light energy  C6H12O6 + 6 O2 + 6 H2 O

  35. Cellular Respiration

  36. How Cells Harvest Chemical Energy Introduction to Cell Metabolism Glycolysis Aerobic Cell Respiration Anaerobic Cell Respiration

  37. Breathing and Cell Respiration are related BREATHING O2 CO2 Lungs Muscle cells carrying out CO2 Bloodstream O2 CELLULAR RESPIRATION Sugar + O2 ATP + CO2 + H2O

  38. Cellular Respiration uses oxygen and glucose to produce Carbon dioxide, water, and ATP. Glucose Oxygen gas Carbon dioxide Water Energy

  39. How efficient is cell respiration? Energy released from glucose banked in ATP Energy released from glucose (as heat and light) Gasoline energy converted to movement 100% About 40% 25% Burning gasolinein an auto engine Burning glucose in an experiment “Burning” glucosein cellular respiration

  40. Reduction and Oxidation OILRIG Oxidation is losing electrons Reduction is gaining electrons Loss of hydrogen atoms Energy Glucose Gain of hydrogen atoms Glucose gives off energy and is oxidized

  41. General Outline • Glucose Glycolysis No Oxygen Anaerobic Oxygen Aerobic Pyruvic Acid Transition Reaction Fermentation Krebs Cycle ETS 36 ATP

  42. Glycolysis Where? The cytosol What? Breaks down glucose to pyruvic acid

  43. Steps – A fuelmolecule is energized,using ATP. Glucose 1 3 Step Glycolysis 1 Glucose-6-phosphate 2 Fructose-6-phosphate Energy In: 2 ATP 3 Fructose-1,6-diphosphate Step A six-carbonintermediate splits into two three-carbon intermediates. 4 4 Glyceraldehyde-3-phosphate (G3P) 5 Step A redoxreaction generatesNADH. 5 1,3-Diphosphoglyceric acid(2 molecules) 6 Steps – ATPand pyruvic acidare produced. 3-Phosphoglyceric acid(2 molecules) Energy Out: 4 ATP 6 9 7 2-Phosphoglyceric acid(2 molecules) 8 2-Phosphoglyceric acid(2 molecules) NET 2 ATP 9 Pyruvic acid (2 moleculesper glucose molecule)

  44. General Outline of Aerobic Respiration • Glycolysis Transition Reaction Krebs Cycle Electron Transport System

  45. Transition Reaction Each pyruvic acid molecule is broken down to form CO2 and a two-carbon acetyl group, which enters the Krebs cycle Pyruvic Acid Acetyl CoA

  46. General Outline of Aerobic Respiration • Glycolysis Transition Reaction Krebs Cycle Electron Transport System

  47. Krebs Cycle Where? In the Mitochondria What? Uses Acetyl Co-A to generate ATP, NADH, FADH2, and CO2.

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