USC BISC 330 Final - Photosynthesis

USC BISC 330 Final - Photosynthesis

1. Rhodopseudomonas viridus

   • P960
     • P960
       • Bacteriochlorophyll b ->
         • Bacteriopheophytin
           • 10 picosecond to transfer e- to here!
           • no Mg
           • Quinone A
             • Semiquinone B
               • Light
               • Quinone B H2
                 • 2H+
                 • Cytochrome bc1 Complex
                   • Completes cyclic e- transfer
         • has Mg
       • <- Heme from Cytochrome C
         • Donates e- to neutralize charge
           • Fe3+
           • Keeps e- from Falling back down to P960
         • Fe2+
     • Light
     • Photo-induced Charge Separation
     • Reaction Center sits in Periplasm Membrane
     • Anchored by long Fatty Acid tail

2. Plants

   • PS II
     • P680
       • <- Mn Ca Oxygen Evolving Complex
         • 4 Light
           • Antennae, Light Harvesting Complexes
             • Resonance energy transfer by EM interactions
         • 2 H2O from Lumen
         • Donates 4e- to neutralize charge
           • O2 to Lumen
           • 4H+ in Lumen
         • 4 step Oxidation by 4 Photons
     • Pheophytin
       • Plastoquinone
         • 2 Plastoquinol
           • Cytochrome bf Complex
             • 1 e- at a time
               • Cu2+ -> Cu+
             • Semiquinone
               • QH2
                 • 2H+
                 • Can reduce Plastocyanin again, so we get double H+ yield
                   • 4H+
                     • 3 ATP
                       • Where did we get 12 H+?
               • 2H+
                 • Into thylakoid lumen
                   • • ATP Synthase
                     • Proton Gradient powered, no Electrochemical Force
                     • Cl- and Mg2+ can freely cross Thylakoid Membrane
                     • Mg2+ Ions
                       • Activates
                   • CF0
                     • CF1
                       • Bulky, cannot fit in folds
           • 2 Plastocyanin
             • PS I
               • 4 Light
               • P700
                 • Chlorophyll A0
                   • Quinone A1
                     • 4 Ferredoxin
                       • Ferredoxin NADP Reductase
                         • FAD
                         • In Stroma
                       • FADH+
                         • FADH2
                           • 2 NADPH
                             • Thus needs 8 photons!
                             • Takes 2 H+ from Stroma
                               • Does not contribute to Gradient!
                           • NADP+
                             • If Low, Redirected
                           • Returns to FAD
                       • Cytochrome bf Complex
                         • 8H+
                         • 2 Plastocyanin
                           • e- Recycled back
                       • Thioredoxin
                         • Active Calvin Cycle enzymes (Rubisco)
                         • Ferredoxin reduction power breaks Disulfide Bridges
                     • 1 e- at a time
                       • Fe/S clusters
                 • Paraquat
                   • Sucks up e-
                     • R.O.S
             • Faces Thylakoid Lumen
         • PSII Inhibitor
           • Bind to QB
           • Urea derivative, looks like Ligand
     • Special pair of pigments acts like a "sink"

3. Pigments

   • Carotenoids
   • 400
     • 450
       • 500
         • 600
           • 650
   • Chlorophyll a
     • Methyl
     • Chlorophyll a
   • Chlorophyll b
     • Formyl
     • Chlorophyll
   • Phycoerythin
     • Phycocyanin
     • Aquatic

4. Thylakoid Space

   • Granum
     • ATP Synthase
       • access to ADP
     • PS I
       • access to NADP+
   • Granum
     • Thylakoid Space
       • Granum
     • PS II
       • all areas, Proton Gradient
   • Cytochrome bf

5. Calvin Cycle

   • Ribulose 1,5-BP
     • Enediolate
       • 6-C Unstable
         • 3-Phosphoglycerate
           • 1,3 BPG
             • GADP
               • F1,6 BP
                 • F6P
                   • G6P
                     • Hexose
                   • 4C Aldose P
                     • 5C Ketose P
                       • 5C Ketose P
                         • Ribulose 5-P
                       • Xylulose 5-P
               • 7C Ketose 2P
                 • DHAP
                 • 7C Ketose P
                   • 5C Aldose P
                     • 5C Ketose P
                     • Ribose 5-P
                   • 5C Ketose P
                     • GADP
                     • 5C Ketose P
                       • Ribulose 1,5-BP
                         • 3 ATP
                         • Needs 6 Per Hexose
                       • Ribulose 1,5-BP
                       • Ribulose 1,5-BP
                     • Xylulose 5-P
               • NADPH
             • ATP
         • 3-Phosphoglycerate
         • CO2
           • 6 Cycles to get 2 DHAP, 4 GADP, 2 F1,6P, 1 Hexose
           • Concentrated using C4 Pathway
           • Oxaloacetate->
             • Malate
               • <- Pyruvate
                 • PEP
                   • "2 ATP"
                     • cuz it leaves as AMP
               • CO2 (In Bundle Sheathe Cell)
                 • Calvin Cycle
               • - NADPH
               • + NADPH
             • Mesophyll
         • Hydrolysis
       • Carboxylation
       • Hydroperoxide Intmd
         • Phosphoglycolate
           • Glycolate
             • Glyoxalate
               • Glycine
                 • Serine
                   • 3-Phosphoglycerate <-
                   • NH3
               • Glycine
                 • CO2
                   • Lost
                   • Organic molecules converted to CO2 without any ATP or NADPH made
                 • NH4+
                   • Glutamine
                   • Glutamate
                   • ATP
                 • Mitochondria
               • O2
                 • Photorespiration
               • H2O2
             • Peroxisome
         • 3-Phosphoglycerate
         • O2
           • Binds 25 times less strongly than CO2, but how about times when CO2 is limiting?
           • Affinity increases with Tempearture
             • Thus Tropicals at most risk
             • Since CO2 is less soluble at Higher T
     • Dehydrogenated
   • Ribulose 1,5-BP Carboxylase/Oxygenase
     • Exergonic and Rate-Limiting Step
     • 8 Regulatory Subunits
     • 8 Large Catalytic Subunits
       • Lysine
         • CO2 binds here to create Carbamate
           • Mg2+
             • Binds to Ru 1,5-BP C=O and O-H
     • Rubisco for plants 8 times more specific for Carboxylase
   • Aldolase
     • Aldol Condensation
   • Transketolase
   • Phosphatase
   • Transketolase
   • Phosphopentose Epimerase
   • Phosphopentose Isomerase
   • Phosphoribulose Kinase
   • PEP Carboxylase