🎵 Luyện Nghe Bài Hát: Photosynthesis - The Light Reactions - Glenn Wolkenfeld

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