Related topics 11 relations. In the core antennae, the primary function of β-carotene appears to be quenching of triplet chlorophyll (Groot et al., 1995, 1999; Jordan et al., 2001), while the two carotenes in the PS II reaction center act as quenchers of singlet oxygen (Telfer, 2002) and are involved in cyclic electron transfer in PS II (Tracewell and Brudvig, 2003; Ishikita et al., 2007). ATP synthase consisting of (i) a hydrophobic membrane-bound portion (CF0) that forms a channel to allow protons to be passed through the membrane and (ii) a portion that protrudes into the stroma (CF1) and is made up of several peptides (McCarty et al., 2000). Thus, NR might function as a source of NO in plants. Figure 29.1. The core of the reaction center consists of two membrane proteins known as D1 and D2, as well as other proteins. Although the emerging evidence suggests that NO has an important role in plant growth, development, and stress response (Yu et al., 2014), the source of NO remains controversial (Yu et al., 2014). 22:46. The latter suggestion was inferred from both in vitro and in vivo studies of the antioxidant activity of astaxanthin and its esters (Kobayashi et al., 1997a; Kobayashi and Sakamoto, 1999). These fatty acids are released to the endoplasmic reticulum for chain elongation and desaturation (Chi et al., 2008). 8 Steps to a Clean Balance – and 5 Solutions to Keep It Clean. During proton translocation, the stroma becomes alkaline while the lumen becomes acidic. Thus, the expression of cytochrome b6f subunits is seemingly hierarchical with the presence of cytochrome b6 and subunit IV being required for sustained expression of the CES subunit cytochrome f. Studies of Chlamydomonas mutants have uncovered similar hierarchies in the synthesis of chloroplast-encoded subunits from all major photosynthetic proteins, as illustrated in Figure 29.1. However, a NOS similar to those found in mammals has not been found in higher plants. Restored PsaB synthesis in this suppressor strain is correlated with that of PsaA, suggesting that the presence of PsaB is required for efficient translation of the psaA mRNA (Stampacchia et al., 1997). • PQH 2 and PC are mobile carriers that can transport electrons between distantly separated photosystems. The Cyt b6f complex is a large multi-subunit protein with several prosthetic groups containing two b-type hemes and one c-type heme (Cyt f). It is phylogenetically related to the cytochrome bc 1 complex of mitochondria and photosynthetic bacteria (Widger et al., 1984), with which there are many structure-function similarities. A novel thylakoid membrane protein (ssr2016, PGR5) transfers the recycled electron from ferredoxin to plastoquinone (Yeremenko et al., 2005). Along with the Tat pathway, thylakoid or lumenal targeting can occur via two other pathways with bacterial homologues, the Sec and SRP routes (Michl et al., 1994; also see Chapter 19). In the light-dependent reaction, adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH) are generated via proton motive force and the electron transport chain (Figure 1). Since crystallization experiments are generally performed at low LPRs, weak lipid adsorption may have some effects. In particular, cyanobacteria require acyl carrier protein as a cofactor not only to elongate fatty acids but also to generate glycerolipids. What is the Correct Way to Check Repeatability in Balances? Abbreviations: Fd: ferredoxin; FNR: Fd–NADP reductase; PSI and PSII: photosystems I, II; PQ: plastoquinone; PC: plastocyanin. Contrasted effects of inhibitors of cytochrome b6f complex on state transitions in Chlamydomonas reinhardtii: The role of Q o site occupancy in LHCII kinase activation. These three pathways differ not only in their protein specificities but also from an energetic point of view. Descriptors are arranged in a hierarchical structure, which enables searching at various levels of specificity. Light absorbed by carotenoids or Chlb in the LHC proteins is rapidly transferred to Chla and then to other antenna pigments that are closely associated with the reaction center (Lawlor, 2001; Taiz and Zeiger, 2010). What does cytochrome b6f complex mean? Le complexe cytochrome b6f, ou complexe de cytochromes b6f, est une oxydoréductase qui catalyse la réaction: Cette réaction est analogue à celle catalysée par la coenzyme Q-cytochrome ''c'' réductase de la chaîne respiratoire dans les mitochondries. 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