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Published byJacey Colby Modified over 10 years ago
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The Dark Side of Photosynthesis In stroma In 3 stages
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Dark Reaction/ Calvin Cycle
of Photosynthesis In stroma In 3 stages
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Dark Reaction/ Calvin Cycle
uses ATP and NADPH (from light reaction) to convert CO2 to sugar
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Dark Reaction/ Calvin Cycle
Phase 1: Carbon Fixation Phase 2: Reduction Phase 3: Regeneration of RuBP
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We are in the STROMA
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We are in the STROMA
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phase 1 Carbon Fixation --> X3
CO2 attaches to a 5C sugar Ribulose Biphosphate (RuBP) via. Rubisco: P-C-C-C-C-C-C-P Rubisco (RuBP carboxylase) = enzyme
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phase 1 Carbon Fixation --> X3
2)very unstable molecule immediately splits to form 2 molecules of 3 PGA (carbonphosphoglycerate) P-C-C-C C-C-C-P
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We are in the STROMA
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forming 1, 3 biphosphoglycerate
phase 2 Carbon - Reduction > X3 addt’l phosphate group to each 3-phosphoglycerate from ATP (from light reaction) : P-C-C-C-P P-C-C-C-P forming 1, 3 biphosphoglycerate
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We are in the STROMA
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(stores more potential energy) (same sugar as in glycolysis)
phase 2 C - Reduction --> (X3) 2)reduced (e- gained) by NADPH (from light reaction) to make G3P P-C-C-C P-C-C-C (stores more potential energy) (same sugar as in glycolysis)
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We are in the STROMA
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phase 2 Reduction --> (X3)
3)one G3P molecule exits (used later by the plant) P-C-C-C P-C-C-C P-C-C-C P-C-C-C
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We are in the STROMA
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phase 3 Regeneration of CO2 acceptor RuBP -->
1) series of reactions rearranges the 5 G3P molecules into 3 RuBP … using up 3 more ATP’s.
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We are in the STROMA
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RuBP is then prepared to receive CO2 again
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For 1 G3P molecule the one that exited… (precursor to sugar) the cycle:
uses 9 ATP uses 6 NADPH uses 3 CO2
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We are in the STROMA (6)
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