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 Photosynthesis
 Non Cyclic Electron Flow and  Calvin Cycle
 Amusical Lecture  Glenn Wolkenfeld
 
  for joining us for Episode Two,
 Wher more  photosynthesic waits for you.
 We last saw how  cells create, O¬¬2, ATP, and NADPH.
 Now we’ll start with a twist on  light reactions,
 Called  flow, we’ll see how it happens.
  we will investigate how the Calvin Cycle makes carbohydrate.
 
 (Part I, Cyclic Electron 
 Non – cyclic flow is also called the “Z – scheme”  Z on its site and see what I mean.
 Electrons rise  energy then fall and rise again.
 Making ATP and  my friends.
 A variation on this  cyclic flow.
 Which makes ATP, no NADPH or 
 Cyclic flow results  the Calvin Cycle’s needs.
 It  less NADPH than ATP.
 NADPH buildup has the repercussion,  inhibiting NADP+ reduction.
 ‘cause  clogs up reductase.
  NADP+ from moving into place.
  electrons don’t go to NADP+.
  clogged, stuck like a pimple’s pus.
 Where can  go from P700?
 Nature evolved them a place  flow.
 A shunt pathway moves them  the ETC.
 I’m talking ‘bout the one in PS II tou 
 These energized alectrons flow  release energy.
  as you know is used to synthesize ATP.
 
 ( Part  Calvin Cycle)
 Now it’s time to learn the cycle named for 
 Which results  the fixation of carbon.
 Consider that each carbon in  bones, blood and hair,
  once in a CO2 in the air.
 The Calvin  has three parts.
  of carbon is how it starts.
 The molecules produced  then reduced.
 ‘cause reduction is the key thing that happens in  2.
 Part 2 is the  as you will see.
 It produces  G3P
 A  molecule with lots of energy.
 And a starting point for all  molecules that cells need.
 Part 3 sets up conditions for the cycle’s 
 By recreating  at the cycle’s heart.
 RuBP (Ribulose Bisphosphate), a five carbon molecule that seems to 
 ‘Cause RuBP’s  the cycle’s start.
 Then reappears at the very  part.
 The role of RuBP at the start and 
 Is why this is a cycle like the one  Krebs.
 The cycle’s inputs are know  you: NADPH and ATP and CO2
 Fixation of carbon is catalyzed  RuBP Carboxylase Enzyme
  enzyme’s nickname you should know.
 Sounds like a cookie  it’s RUBISCO.
 An enzyme so old it was already 
  O2 accumulated in the air.
 The CO2 enters through leaf stoma,  through the leaf and arriving at the stroma.
 There RuBisCO grabs it in its active site, and squeezes  with RuBP tight.
 RuBP has carbons five, it has two phosphates, one on  side.
 When CO2 combines  RuBP it makes a six carbon compound you won’t see.
 It instantly dissociates into two 3 – 
 Each  three carbons and one phosphate.
 Each  phosphorylated to bisphosohoglycerate.
 Phosohorylated means that each receives aphosphate group from 
  phospharylation, is followed by reduction.
 And you know  an enzyme with the function.
 Of taking electrons and H from NADPH and  them to to bisphosphoglycerate.
 Take off a phosphate for  – Phosphate.
 A  point for compounds like carbohydrates.
 
 (Part III:  Cycle, conclusion)
 Glyceraldehyde- 3 – phosphat,  as G3P,
  a product cells harvest, and I hope you see,
 how light  NADPH and ATP,
 are needed to fix CO2  make organic energy.
 And to  the cycle we must now regenerate.
 The starting  of Calvin Cycle ribulose bisphosphate.
 The  involved in taking G3Ps,
 And recombining them into 
 Are too much  freshman biology.
 You can get the details when you get  Ph. D.
 But know for now that to get 3  from 5 G3Ps cost 3 ATPs!
 
 (Part IV: Conclusion)
 Now this journey  whit its emphasis,
  the reaction of photosynthesis.
 For over  billion years it’s been the food chains basis.
 In  from that era you can see the traces,
 Of tiny  with prokaryotic form.
 Stromatolites  lived in waters warm.
 Through  they transformed our planet,
 So aerobic  can live upon it.
  so evolved sentient beings who can analyze,
  photoautotrophs can photosynthesize.
 You could say that photosynthesis gave birth to codiyions  cons ciousness on Planet Earth!