5 Fosforylacja oksydacyjna niecykliczna(1)

Thylakoid

Chloroplast

Outer membranę membranę

2H⁺

Cytochrome btf

PSI

8H+

4H⁺ + O,

2H*0

Figurę 24-17 Schcmatic representation of the thylakoid membranę showing the componcnts of its clectron-transport chain. The system consists of threc protein complexcs: PSU. the cytochrome fc₆/complex. and PSI. which are electrically “connected" by the diffusion of the elcctron carriers p!astoquinol (O) and plastocyanin (PC). Light-driven transport of electrons (btack arrows) from H₂0 to NADP* forming NADPH motivates the transport of protons (red arrows) into the thylakoid space (Fd is ferrcdoxin). Additional protons are split off from water by

Thylakoid 3H⁺ translocating lumen ATP synthase

+ 2NADP+

Stroma

Fd-NADP⁺

reductase

the oxygen-evolving complex (OEC), yielding 0₂.The rcsulting proton gradient powers the synthesis of ATP by the CFjCF₀ proton-translocating ATP synthase [CFi and CF₀ are chloroplast (C) analogs of mitochondrial Fi and Fol-The membranę also contains light-harvesting complexes whosc component chlorophylls and other chromophores transfer their cxcitations to PSI and PSII. (After Ort. D.R. and Good. N.E., Trends Hiochem. Sci. 13,469 (1988).!