Flashcards
Photosynthesis
Cards in this deck (18)
- 1What are the 2 types of photosynthesis?Anoxygenic (cyclic)
Oxygenic (generates oxygen from water) - 2Name a model organism for understanding cyclic photosynthesisRhodobacter
- 3Name the things & complexes in the structure of the rhodobacter light harvesting complexreaction centre
light harvesting complex 1
light harvesting complex 2
(reaction centre in the middle, surrounded by LHC1 horseshoe, LHC2 on outside) - 4What is another name for the light harvesting complex 2?peripheral antennae
- 5What is another name for the light harvesting complex 1core antenna
- 6In short, how does the rhodobacter mechanism work?LH2 & LH1 channel light towards the reaction center and the reaction center converts light E to chemical E
- 7How many proteins is the reaction center made of and what are their names?3;
Heavy
Light
Medium - 8Which of these proteins contain cofactors?H & L
- 9What is the mechanism for rhodobacter?1) Light energy is aborbed by Bchl800, and it becomes ‘excited’
2) As excited Bchl800 decays back to ‘normal’, energy is released
3) Bchl850 is close enough, and the energy is of the correct wavelength, to excite this chlorophyll
4) Excited Bchl850 decays back to ‘normal’, and energy is released
5) This can excite another Bchl850 in LH2 (and so on round the ring)
6) or this can excite a Bchl870 in LH1
7) Excited Bchl870 decays back to ‘normal’, and energy is released
8) This can excite another Bchl870, and so on round the ring
9) or this can excite the ‘special pair’ in the reaction centre
10) The excited special pair passes an electron to Bchl (A)
11) Bchl (A) passes electron to Bpheo (A)
12) Bpheo (A) passes electron to quinone in Q (A) site - 10...continued13) electron passes to quinone in Q (B) site to form a semi-quinione
14) Cytochrome c2 reduces the special pair
15) special pair’ get excited by energy from light again (transferred by LH2 and LH1)
16) special pair passes the second electron to Bchl (A)
17) Bchl (A) passes the second electron to Bpheo (A)
18) Bpheo (A) passes the second electron to quinone in Q (A) site
19) second electron passes to semi-quinone in Q (B) site to form quinol
20) Quinol interacts with the cytochrome bc1 complex to form quinone
21) cytochrome bc1 undergoes the q-cycle and generates proton motive force
22) Now reduced cytochrome c2 can re-reduce the special pair - 11what is a model organism for oxygenic photosynthesisCyanobacteria
- 12What do cyanobacteria use as an e- donor?H2O
- 13Where are the light harvesting pigments and the photosynthetic e- transfer systems located?in the internal thylakoid membrane systems
- 14How many photosystems are involved?two
- 15In short, what does photosytem 2 do?it captures light and converts it
- 16How does non cyclic photosynthesis work?1) P680 Special chlorophylls get excited by energy from light
2) P680 passes an e- to Pheo (D1)
3) Pheo (D1) passes the e- to plastoquinone in the A site
4) The e- is passed to plastoquinone in the B site to form a semi quinone
5) 1 of 4 e- is extracted from the Mn4Ca2+O5 water-splitting-oxygen-evolving complex7
6) The Mn4Ca2+O5 cluster replenishes its own e- by splitting water
7) P680 special chlorophylls get excited by a second quantum of light E
8) P680 passes second e- to Pheo (D1)
9) Pheo (D1) passes 2nd e- to plastoquinone in A site
10) 2nd e- is passed to semi-quinone in the B site to form plastoquinol
11) Plastoquinol interacts with the cytochrome B6f complex
12) Plastocyanin replenishes the special e- lost from complex I P700 chlorophylls - 17And again to summariseLight -> P680 chlorophylls -> Pheo (D1) -> plastoquinone in A site -> plastoquinone in B site -> (semi quinone is formed) -> an e- is extracted from Mn4Ca2+O5 -> Mn4Ca2+O5 splits water to replenish its own e- -> P680 excites by light again -> Pheo (D1) -> plastoquinone in A site -> semi-quinone in B site -> (plastoquinol is formed) -> plastoquinol interacts with cytochrome of B6f complex -> plastocyanin replenishes special e- lost from complex I P700 chlorophylls
- 18Name the proteins in the light harvesting complex IICP43, CP47, D1, D2
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- Biochemistry & cell biology (Bioenergetics & Photosynthesis) Flashcards on Photosynthesis, created by Sophia Puliasis on 06/12/2017.
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- Sophia Puliasis
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