Z-Scheme of Photosynthesis

Integration of PS II and PS I via cyt b6f in chloroplasts (Z scheme of photosynthesis). Pheo a represents pheophytin pQA and pQB represent phytoquinone A and B, respectively A, and At represent electron acceptor chlorophylls, respectively pc represents plastocyanin and Fd represents ferridoxin. 

The pathway of electron flow is called the Z scheme of photosynthesis because the diagram from p680 to p700 resembles the letter Z (Figure 7.10) [37,39]. 

Fig. 26. Z-Scheme of photosynthesis in plants. Chi is chlorophyll, cyt b, f is cytochrome b, / PC is plastocyanine, (Fe-S) is iron sulfer protein. ATP is adenosine triphosphate ADP is adenosine diphosphate Pj is the phosphate ion and NADP is the nicotinamide adenine dinucleotide phosphate ion [203]...

What is the Z scheme of photosynthesis How are the products of this reaction used to fix carbon dioxide ... 

Figure 28 The Z-scheme of photosynthesis for cyanobacteria (from Cornet et al., 1998). The cyclic photophosphorylation pathway enabling values of P/2e greater than 1.0 is indicated.

As for the previous conditions of appHcabihty, it is then possible to use hnear phenomenological thermodynamics of irreversible processes to analyze the couphng between redox reactions leading to reducing NADPF12 synthesis (specific molar rate Jcof) and the photo-phosphorylation mechanisms leading to ATP synthesis (specific molar rate Jatp) according to the Z-scheme of photosynthesis (Fig. 28). The ratio of these two mean specific rates is defined as the P/2e ratio (see Eq. (120)) ... 

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