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 Photosynthesis
 Non  Electron Flow and The Calvin Cycle
 Amusical Lecture by Glenn 
 
  for joining us for Episode Two,
 Wher more  photosynthesic waits for you.
 We last saw how plant cells create, O¬¬2, ATP,  NADPH.
 Now we’ll start  a twist on the light reactions,
  cyclic flow, we’ll see how it happens.
 Then we will investigate how the Calvin Cycle makes 
 
 (Part  Cyclic Electron Flow)
  – cyclic flow is also called the “Z – scheme” Put Z on its site and see what I mean.
 Electrons rise in energy  fall and rise again.
 Making ATP  NADPH my friends.
 A variation on this  cyclic flow.
 Which makes ATP, no  or O.
 Cyclic  results from the Calvin Cycle’s needs.
 It uses less NADPH  ATP.
 NADPH buildup has  repercussion, of inhibiting NADP+ reduction.
 ‘cause NADPH clogs  reductase.
  NADP+ from moving into place.
 So electrons don’t go to 
 They’re clogged, stuck like a  pus.
 Where can they go from 
 Nature  them a place to flow.
 A shunt pathway moves them  the ETC.
 I’m talking ‘bout the  in PS II tou see.
 These energized alectrons flow and release 
 Which as you know is used  synthesize ATP.
 
 ( Part II: Calvin 
 Now  time to learn the cycle named for Calvin.
 Which results in the fixation of 
 Consider that each carbon in your bones,  and hair,
 Was once in a CO2 in the 
 The Calvin  has three parts.
 Fixation of carbon  how it starts.
 The molecules  rae then reduced.
 ‘cause reduction  the key thing that happens in part 2.
  2 is the payoff as you will see.
  produces molecule G3P
 A reduced molecule with  of energy.
 And a starting point  all the molecules that cells need.
 Part 3 sets up conditions for the cycle’s 
 By recreating what’s  the cycle’s heart.
 RuBP (Ribulose Bisphosphate), a five carbon molecule that seems to 
 ‘Cause RuBP’s at the cycle’s 
 Then reappears at  very last part.
 The role of RuBP at  start and end.
 Is why this is  cycle like the one named Krebs.
 The cycle’s inputs are know  you: NADPH and ATP and CO2
 Fixation of carbon is  by RuBP Carboxylase Enzyme
  enzyme’s nickname you should know.
 Sounds like a  maker: it’s RUBISCO.
 An enzyme  old it was already here,
 Before  accumulated in the air.
 The CO2 enters through leaf stoma, diffusing  the leaf and arriving at the stroma.
 There RuBisCO  it in its active site, and squeezes it with RuBP tight.
 RuBP has carbons five, it has two phosphates,  on each side.
 When CO2 combines with RuBP it makes a six carbon  you won’t see.
 It  dissociates into two 3 – phosphoglycerates,
 Each with three carbons  one phosphate.
  gets phosphorylated to bisphosohoglycerate.
 Phosohorylated means that  receives aphosphate group from ATP.
 This phospharylation,  followed by reduction.
 And you  there’s an enzyme with the function.
 Of taking electrons and H from NADPH and adding them to  bisphosphoglycerate.
 Take off a phosphate for  – Phosphate.
 A starting point  compounds like carbohydrates.
 
  III: Calvin Cycle, conclusion)
 Glyceraldehyde- 3  phosphat, known as G3P,
  a product cells harvest, and I hope you see,
 how light  NADPH and ATP,
 are  to fix CO2 and make organic energy.
 And to complete the cycle we must  regenerate.
 The starting point of Calvin Cycle ribulose 
  intermediates involved in taking G3Ps,
 And recombining them  RuBPs.
 Are too much for freshman 
 You can get the details when you  yors Ph. D.
 But know for now that to get 3 RuBPs from 5 G3Ps cost  ATPs!
 
 (Part IV: Conclusion)
 Now this journey ends whit  emphasis,
 On the reaction of 
 For over four  years it’s been the food chains basis.
 In fossils from  era you can see the traces,
 Of tiny cells  prokaryotic form.
 Stromatolites that lived in waters 
 Through photosynthesis they transformed our 
 So aerobic life  live upon it.
 And so evolved sentient  who can analyze,
 How photoautotrophs can 
 You  say that photosynthesis gave birth to codiyions for cons ciousness on Planet Earth!