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 Photosynthesis : part  - The Light Reactions
 Amusical  by Glenn Wolkenfeld
 
 A music Lecture by Glenn 
  and girls tell me what you think of this,
 Time  a lesson ‘bout photosynthesis
 Cells use light  combine water carbon dioxide.
 Gonna see  going for a wild ride.
 Making  making sweet O¬2.
 But why  photosynthesis matter to you?
 Food on your 
 O2 rich atmosphere.
 Without photosynthesis you simple wouldn’d be 
 
 ( Part  The Big Picture)
 Photosynthesis  a redox reaction.
 Powered  light using enzymatic action.
 Water’s  CO2’s re duced
 The sugar that results  drink in orange juice.
 The overall reaction has  phases.
 First is the light reactions  has as its basis.
 Light powered production  ATP.
 O2 is the by – product and you will 
  of electron carrier NADPH
 Which provides reducing  needed in the second phase
 ‘Cause NADPH, during phase 
 Provides what’s needed  reducing CO2
 NADPH ia  by a reduction of NADP+, whose function
 Is to absorb electrons and  up H,
 Gaining  and making NADPH.
 Phase 2 is  Calvin Cycle makes carbohydrate,
 Like sugar and  and fibers on your lunch plate.
 It’s how plants make food  eat.
 Photosynthesis,  so sweet!
 
 (Part II: Chloroplasts, Thylakoids,  and Chlorophyll)
 In  lesf there’s mesophyllic tissue
 And cells with chloroplasts key to  issue.
 Chloroplasts are almost  cells in every way,
 With their own ribosomes and their  DNA.
 They even  themselves, splitting into half.
  clue for this organelle’s independent past.
 This  has a name endosymbiosis,
  in the 60s by Lynn Margulis.
 Inside the chloroplast is the fluid 
 It’s true  Tokyo.
 It’s  in Roma.
  syrrounds little thylakoids.
 Each one has a hollow space 
 The thylakoid’s membrane is loaded with 
 ‘Cause it’s the  reactions’ scene.
 It’s all about  light for powering electrons,
 All about grabbing the power  photons.
  photons needed are are those from light,
 Which has the energy to  the world bright.
 The  frequency that we can see,
 Is violet light with wavelength 
 380  sounds small,
 But next to gamma rays it’s  tall.
 Red light shines  750.
 Isn’t  visible spectrum nifty?
 Photons are  of light energy,
 Both  wave and a particle, you see.
 Phootins  adsorbed by pigments.
 It’s real, it’s  it ain’t no figment!
 Most important  green chlorophylls.
  carotenoids, and yellow xanthophylls.
 Together  absorb light, mostly red and blue.
 The green is not absorbed it reflects back  you.
 In chlorophyll see  porphyrin ring.
 See the magnesium, which  you want to sing,
 Magnesium, metal with valence 
 You’ll see those electrons rocketing 
 Notice  tail, a hydrocarbon chain.
 Which anchors chlorophyll  the thylakoid membrane.
 A molecule with  so pretty,
  the thylakoid it makes electricity!
 
 ( Part III)
 Englemann  us the action spectrum.
 Used a prism to break  sun’s
 Light  its frequencies.
  it on spirogyra, filamentous algae.
 The O2 algae  will stimulate bacteria.
 Which will grow  any oxygen – rich area.
  loved it over blue and red,
 But hardly grew over green, they might as  be dead!
 The line of growth  a refection, of photosynthesis’ action spectrum.
 Note this won’t match, 
 The absorption  of chlorophyll a or b.
 ‘Cause the cartenoids and  we’ve met,
 Absorb light frequencies the chlorophylls can’t 
  in the thylakoid they all cooperate,
  using light to synthesize carbohydrate.
 Consider chlorophyll  isolation,
 Shine  light upon it (call it photoexcitation)
  valence electrons in magnessium
 Jump to an excited state,  so fun!
 But once up at that level, they can  fall.
 Back to where they started, like  bouncing ball.
 These falling  release energy,
 Fluorescing as red light, as you can 
 But in thylakoids, chlorophyll’s not 
 Instesd a photosystem  chlorophyll’s home.
 The photosystem’s parts  take photons,
 And use their energy  move electrons.
 The  antenna complex does the first capture,
 Changing photon anergy into  rapture.
 The energized electrons bounce like a 
 At the reaction center, they jump but do not 
 A primary electron acceotor  them from on top,
 And yanks them  a force reaction center cannot stop.
 To  oxidized reaction center we’ll return,
 But the details of  flow it now is time to learn.
 
 ( Part IV) ATP Synthesis in Non –  Electron Flow.
 Non -  cycle flow is the main pathway.
 Much confustion relates  the way
 Hootoystm II precedes photosystem 
  a fct to memorize, just get it done!
 PS  antenna captures a photon,
  a flow of electrons.
 All around the world, even  Haiti,
 They flow  reaction center P680.
 There electrons do  hover,
 Electron acceptor passes them 
 To  electron transport chain,
 In  thylakoid membrane.
 This chain’s like a bucket 
 Each  has a similar trade.
 They  energized electrons,
  use their energy for pumping protons.
 From stroma to the thylakoid 
 Packing protons  that place.
  makes a gradient across the thylkoid membrane
 The protons want “out” or  go insane.
  the protons can’t permeate.
 The membrane  allow escape.
 There’s only one  through which they travel.
 It’s the ATP Synthase 
 The “-ase” tells you this is an 
 Which  ATP all the time.
  has binding sites for ADP and Pi,
  channels for diffusing protons whose knetic energy.
 Changes the  sites’ conformation.
 Fusing ADP with Pi which  your information.
 Is how  make ATP.
 Life’s  form of energy.
 From respiration  might feel familiar.
 ATP is  this way in mitochondria.
 Chemiosomosis is  name
  production is the game.
 
 ( Part V: NADPH Synthesis  Non – Cyclic Elecron Flow)
 Back  our electons moved by the sun.
 Flowing from Photosystem II to System 
 They get to PS I  a used up battery.
 The transport chain used  their energy.
 But when light hits PS I’s 
 Electrons  to reaction center.
 This one’s P700,
  wavelength makes electrons go!
 PS T’s electron acceptor grabs  away,
 Leaving  in an oxidized way.
  P700 with its oxidized blues accepts the alectrons from PS II.
 Bak to electron from  I.
 It now gose  a ride, having its own fun.
 But powering proton pumps  its fate.
 It travels  NADP+ reductase.
 An enzyme  cells count upon.
  pass some H and electrons.
 To NADP+  gets reduced.
 It’s how  get produced.
 
 (Part VI: Oxygen  in Non – Cycli Electron Flow)
 The by – product  these light reactions
 Is oxygen here’s  it happens.
 Back PS II, it  to arise,
 That P680  oxidized
 To replace  electrons P680 liberates.
 Electrons from  which dissociates.
 Into one  and protons two,
 The  O will meet anoher forming O2.
 These protons are formed in  thylakoid space.
 Increasing proton concentration in that 
  we see a side effect of water’s oxidation.
  enhancement of ATP creation.