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Flashcards in Light reactions Deck (15):
1

What takes place in cytb6f

Q cycle - net effect is proton trasnport

2

Structure of cyt6bf

Homodimer form consisting of 4 subunits: cytb6 (cont. 2 b type hemes), cytf (cont. c type heme), Rieske type FeS protein (2Fe-2S cluster), subunit IV

3

What is the role of cytb6f

Mediate electrons between PSI and PSII oxidising PQH2 and reducing PC (QH2-FeS-Cytf-PC)

4

What is plastocyanin

Mobile 1 electron carrier that cycles between Cu+ and Cu2+ - distorted tetrahedral coord

5

PSI

Uses light energy to generate reduced Ferredoxin - >13 subunits, monomeric in euk but trimeric in cyanobac, RC cofactors bound by 11 TM helices, homologous to PSII, P700 RC

6

PSI process

RC contains 6 Chl, phylloquinones, 3[4Fe-4S] clusters, P700 = special pair of Chl a molecules, electron transferred down pathway via Chl to quinone to set of [4Fe-4S] clusters. Electrons transferred to Ferredoxin (soluble proteins)

7

What is ferredoxin

1 electron carrier protein with Fe2S2 centre - very reducing

8

FNR

Flavin nucleotide reductase - generates ATP

9

FTR

Flavin thioredoxin reductase

10

Ferredoxin-NADP+ reductase

NADPH binds - 2 electron carrier, Ferredoxin + FNR complex

11

NADPH

2 electron carrier, efectively an H- (hydride) carrier, source of reductants for calvin cycle

12

Why are 2 photosystems necessary

Plastoquinol to redcuing enough to make NAPHD

13

PGLR1

Ferredoxin plastoquinone reductase

14

How are the H+ ions moving into thylakoid counterbalanced

Mg2+ ions moving out

15

How does ATP synthase generate ATP

Uses proton gradient to translocate protons out of lumen into stroma - rotating mechanism