Lect_12_PSII - Photosynthesis II CO2 Fixation Finish light...

Info icon This preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
Photosynthesis II - CO 2 Fixation Carbon cycle Pathways of CO 2 fixation during PS History C-3 plant and the Calvin cycle carboxylation reduction regeneration Photorespiration C-4 plants and the Hatch-Slack pathway Reductive carboxylation in microorganisms Synthesis of starch Finish light reactions
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Second Midterm: Thursday, Nov. 15, 2007 Will primarily cover materials from lectures 7-12. Review session: Tuesday, Nov. 13, 2007 7:10 - 9:00 pm 1001 Giedt Hall
Image of page 2
A 1 P700 h γ h γ -1.4 cyt bf PC P700 P700 Fd Cyclic electron pathway ATP h γ BIS 103 - #11 - 3 - Photosynthesis - Hill-Bendall Scheme FP (Fd-NADP + oxido reductase) Fd (ferridoxin) FeS protein (phylloquinone) A o (electron accepting chl) NADP + NADPH + H + (non-cyclic) Q A Q B Ph (pheophytin) (plastoquinone) ADP + Pi ATP PC ( plastocyanin ) cyt bf complex Volts Photosystem II Photosystem I P700* P680* -0.432 -0.32 Volts 0.0 +0.8 P680 (cyclic) ATP ADP + Pi -0.8 4e- + 4H + + O 2 2H 2 O Water splitting Mn complex ADP + Pi PS I
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
How does the Z-scheme furnish the ATPs and NADPHs? 2 NADP + + 2H 2 O 2 NADPH + 2H + + O 2 2 ADP + 2Pi 2 ATP Cyclic photophosphorylation results in the following: ADP + Pi ATP 9 photons of light produced 3 ATPs and 2 NADPHs To reduce 1 CO 2 to CH 2 O, requires 3 ATPs and 2 NADPHs 4 photons activate PSI 4 photons activate PSII 1 photon activates PSI Non-cyclic photophosphorylation yields:
Image of page 4
BIS 103 - 11- PS - Quantum requirement for reducing CO 2 to C(H 2 O) CO 2 + 2 NADPH + 3 ATP + 2 H 2 O C(H 2 O) + 2 NADP + + 3 ADP + 3 Pi + O 2 + H 2 O Need one quantum to excite one electron How many quanta are required to reduce CO 2 to C(H 2 O)? - need 4 e- in PSI to synthesize 2 NADPH + H + = 4 quanta - need 4 e- in PSII to fill electron hole in PS1 & make 2ATPs = 4 quanta - need 1 e- in PSI to form 1 ATP by cyclic photophosphorl. = 1 quantum Therefore need 9 quanta of light to reduce 1 CO 2 to 1 C(H 2 O). Total = 9 quanta
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
At 700 nm, 1 quantum (einstein) of light contains about 176 kJ of energy Efficiency of photosynthesis : CO 2 + 2 H 2 O + n (hn) CH 2 O + H 2 O + O 2 G’ = + 477 kJ/mol 477/176 = 2.7 quanta or about 3 quanta of light are required to reduce CO 2 to C(H 2 O) at 100% efficiency. Green plants require 9 quanta, therefore efficiency is 3/9 x 100 = 33% efficiency
Image of page 6
Photosynthesis - CO 2 Fixation or dark reactions Carbon cycle Pathways of CO 2 fixation during PS History C-3 plant and the Calvin cycle carboxylation reduction regeneration Photorespiration C-4 plants and the Hatch-Slack pathway Reductive carboxylation in microorganisms Synthesis of starch
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Carbon cycle - page 51 The carbon cycle on earth involves photosynthesis by plants and microorganisms, which fix CO 2 into organic matter. CO 2 is produced by burning of fossil fuels and by catabolic metabolism of plants, animals, and microorganisms. Animals depend on the products of photosynthesis for their energy supply and oxygen. Plants and some microorganisms are able to convert sunlight energy and CO 2 to metabolizable carbon compounds.
Image of page 8
Photosynthesis Atmospheric CO 2 CO 2 fixation Photolithotrophs Chemolithotrophs Fossil fuel combustion Respiration Heterotrophs Dead organic matters Ocean sediment Coal and oil The Carbon Cycle Animal life is dependent on plants and microorganisms for its energy!
Image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern