Light-harvesting chlorophyll

Owens TG, Shreve AP and Albrecht AC (1992) Dynamics and mechanism of singlet energy transfer between carotenoids and chlorophylls Light harvesting and nonphotochemical fluorescence quenching. In Murata N (ed) Research in Photosynthesis, Vol 4, pp 179-186. Kluwer Academic Publishers, Dordrecht... 

See also Photosystem I, Photosystem Summary, Chlorophyll, Light Harvesting Complex, Figure... 

Chlorophyll molecules form circular rings in the light-harvesting complex LH2... 

The light-harvesting complex LHl is directly associated with the reaction center in purple bacteria and is therefore referred to as the core or inner antenna, whereas LH2 is known as the peripheral antenna. Both are huilt up from hydrophohic a and p polypeptides of similar size and with low hut significant sequence similarity. The two histidines that hind to chlorophyll with absorption maxima at 850 nm in the periplasmic ring of LH2 are also present in LHl, but the sequence involved in binding the third chlorophyll in LH2 is quite different in LHl. Not surprisingly, the chlorophyll molecules of the periplasmic ring are present in LHl but the chlorophyll molecules with the 800 nm absorption maximum are absent. 

Detergent treatment of a suspension of thylakoids dissolves the membranes, releasing complexes containing both chlorophyll and protein. These chlorophyll-protein complexes represent integral components of the thylakoid membrane, and their organization reflects their roles as either light-harvesting com-... 

Hoffman, E., et al., 1996. Structural basis of light harvesting by carotenoids Peridinin-chlorophyll-protein from Amphidinium carterae. Science 272 1788-1791. 

To reveal the light-harvesting process, synthetic studies on cyclic porphyrin oligomers, designed based on the information of the protein structure, are considered. Nature adopted the cyclic alignment of chlorophyll. Is the closed cyclic... 

Chlorophyll b occurs as an accessory pigment of the light-harvesting systems in land plants and green algae, and comprises one-third (or less) of total chlorophyll. The biosynthesis of chlorophyll b has been an area of active research particularly regarding its compartmentalization in chloroplast membranes, identification of the gene for chlorophyllide a oxidase, and characterization of the enzymes involved. ... 

Carotenoids also assist chlorophylls in harvesting light. Carotenoids absorb wavelengths of blue light which chlorophylls do not. The energy that carotenoids harvest in the blue range of the spectrum and transfer to chlorophyll contributes... 

U. Johanningmeier, S. H. Howell (1984) Regulation of light-harvesting chlorophyll-binding protein mRNA accumulation in Chlamydomonas reinhardtii. Possible involvement of chlorophyll synthesis precursors. J. Biol. Chem., 259 13541-13549... 

Carotenoids exhibit multiple physiological roles, i.e. as light-harvesting pigments in photosynthesis, as quenching solutes for the triplet state of chlorophyll a to... 

Nonradiative energy transfer has a major role in the process of photosynthesis. Light is absorbed by large numbers of chlorophyll molecules in light-harvesting antennae and energy is transferred in a stepwise manner to photosynthetic reaction centres, at which photochemical reactions occur. This fundamental energy-transfer process will be considered in more detail in Chapter 12. 

Carotenoids complement chlorophylls in the light-harvesting process. 

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