Chloroplasts chlorophyll

See also Light Absorbing Pigments, Chloroplast Anatomy, Photosystem II, Photosystem I, The Chloroplast, Chlorophyll, Chlorophyll a, Chlorophyll b... 

Inhibition of photosynthesis e--transport photosynthesis Oj-production, chloroplasts (chlorophyll-fluorescence) Atrazine, diuron... 

There are two types of pigments in the chloroplasts, chlorophyll and carotenoids. Besides chlorophyll, the chloroplasts of the red algae contain other tetrapyrrole pigments which are active in photosynthesis, these are the phycobilins. The leaves of green plants often contain in the vacuole (i.e. outside the cytoplasm), pigments such as the anthocyanins which do not play any part in photosynthesis. 

In the chloroplast, chlorophylls a and b (Atlas R3) and carotenoids (of which p-carotene. Atlas El, is an example) bind to integral proteins called light-harvesting complexes, which absorb solar energy and transfer it to protein complexes known as reaction centers, where light-induced electron transfer reactions occur. The combination of a light harvesting complex and a reaction... 

Kolubayev T, Geacintov N E, Paillotin G and Breton J 1985 Domain sizes in chloroplasts and chlorophyll-protein complexes probed by fluorescence yield quenching induced by singlet-triplet exciton annihilation Biochimica Biophys. Acta 808 66-76... 

Light and photosynthetic electron transport convert DPEs into free radicals of undetermined stmcture. The radicals produced in the presence of the bipyridinium and DPE herbicides decrease leaf chlorophyll and carotenoid content and initiate general destmction of chloroplasts with concomitant formation of short-chain hydrocarbons from polyunsaturated fatty acids (37,97). 

Krause, G.H. Behrend, U. (1986). A pH-dependent chlorophyll fluorescence quenching indicating a mechanism of protection against photoinhibition of chloroplasts. FEBS Letters, 200, 298-302. 

Krause, G.H. Laasch, H. (1987). Energy-dependent chlorophyll fluorescence quenching in chloroplasts correlated with quantum yield of photosynthesis. Zeitschrift fiir Naturforschung, 42, 581. ... 

Powles, S.B. Bjorkman, O. (19826). Photoinhibition of photosynthesis effect on chlorophyll fluorescence at 77 K in intact leaves and chloroplast membranes of Nerium oleander. Planta, 156, 97-107. 

These extensive alterations in cell structure and the biochemical machinery are indicative of entry into an ametabolic condition. In this condition damage from free radicals is potentially decreased, certainly the loss of chlorophyll and chloroplast structure removes a major source of free radical generation. About 50% of the extremely desiccation tolerant monocots exhibit extensive loss of chlorophyll and ultrastructural organisation when desiccated. Dicots, ferns and bryophytes retain most of their chlorophyll and exhibit small changes in structure when dry (see Gaff,... 

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. ... 

Although chlorophyll and chlorophyllin colorants seem to be easily obtained, in practice their production as natural food colorants is rather difficult. The sensitivity of chlorophylls to certain enzymes, heat, and low pH, and their low tinctorial strength greatly limit their manufacture and application as food additives, principally when the pigments are isolated from the protective environment of the chloroplasts. The well-known instability of chlorophylls prompted extensive research for developing... 

The photosynthetic apparatus in green plants and algae is located in the chloroplast, which is a flattened, double-membraned structure about 150-200 A thick/4,5 The two flat membranes lie one above the other and are united at their peripheries. These double-membraned structures have been termed thylakoids (from the Greek sacklike )/ Each membrane of the thylakoid consists of a water-insoluble lipoprotein complex which contains the light-absorbing chlorophyll and other pigments utilized in photosynthesis. 

Plastids are any of a number of interrelated organelles occurring in the cytoplasm of plant cells in which starch, oil, protein, pigments, etc., are stored. The chlorophyll-containing chloroplasts, the site of photosynthesis, are referred to as green plastids. 

For example, lignin fluorescence in roots, vascular tissues, and cell walls of aerial plant parts interferes with imaging at wavelengths between 490 and 620 nm while the chlorophyll autofluorescence in leaves and stems is most problematic between 630 and 770 nm. Thus imaging of GFP and its closest spectral variants such as CFP and YFP is most likely to be problematic in roots, whereas RFPs may be hard to discriminate in chloroplast containing aerial plant tissues [17], These problems have only recently been effectively... 

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