light-independant reactions

• where do the light independant reactions take place?

  stroma
• what cycle describes the light independant reaction?

  calvin cycle
• step 1, how does the carbon dioxide get to where it needs to?

  1. carbondioxide diffuses into the stomata and dissolves by the water around the cell of the mesophyll cells then diffuses through the surface membrane , cytoplasm then chlroplast membrane
• step2, what happens after co2 diffuses into the chloroplast?

  • in the stroma co2 reacts with the 5-carbon compound ribulose bisphospate ( RuBP)
  • this reaction is catalysed by an enzyme called ribulose bisphosphate carboxylase ( RUBISCO)
• step3, describe the reaction between carbondioxide and RuBP?

  • carbondioxide and RuBP produces two molecules of the 3-carbon glycerate 3 - phosphate ( GP )
• step4, what happens to GP after?

  • NADPH is used to reduce GP to triosphosphate TP using energy supplied by ATP
  • the NADP is reformed and goes back to the light dependant reaction
• what happens to the TP?

  • some TP molecules are converted to organic substances that plants require such as starch , cellulose ,lipids, ect
  • most TP molecules are used to regenerate RUBP using ATP from the light dependant reaction
• what does RuBP stand for ?

  (five carbon) ribulose bishphosphate
• what does GP stand for?

  ( 3 carbon) 3 -carbonglycerate 3 -phosphate
• what TP stand for?

  triosphosphate
• describe the adaptation of the fluid of the stroma?

  • the fluid of the stroma contains all the enzymes required fr the reactions,
  • stromal fluid is membrane bound in the chroplast so the environment has a high conc of enzymes and subsrates
• describe the adaptation of how the products of the light - dependant products get the to stroma?

  stromal fluid surrounds the grana and so products from the light dependant reactions readily diffuse
• describe another adaptation of the stromal fluid ?

  • it contains dna and ribsosomes so it can quickly and easily manufacture some of the proteins involved in the light - independant reaction