Absorption spectrum, of chlorophyll

Absorption spectra of chlorophyll a and bacteriochlorophyll a. (Modified from Archer and Bolton, in preparation)... 

Figure 23-22 Absorption spectra of chlorophylls and accessory pigments compared. Redrawn from G. and R. Govindjee,265 and from J. J. Wolken 266...

Spectrophotometric assessment of chlorophyll content is based on the strong electronic absorption spectra of these pigments. Arnon (1949) developed an early method measuring 80% acetone/20% water plant extracts based on the electronic absorption spectra of chlorophylls a and b. Absorbance of the extract was measured at different wavelengths, and simultaneous equations were constructed based on extinction coefficients for each derivative s unique electronic absorption maxima. Over the... 

Fig. 7 Absorption spectra of chlorophylls a and b in diethyl ether. Chlorophyll a (-), chlorophyll b...

Fig. 9. The absorption spectra of chlorophyll a in its ground singlet (broken line) and its bleached state. See ref. 79.

If our postulates are correct the most interesting feature of P-450 is the manner in which the protein has adjusted the coordination geometry of the iron and then provided near-neighbour reactive groups to take advantage of the activation generated by the curious coordination. Vallee and Williams (68) have observed this situation in zinc, copper and iron enzymes and referred to it as an entatic state of the protein. It is also apparent that some such adjustment of the coordination of cobalt occurs in the vitamin B12 dependent enzymes. As a final example we have looked at the absorption spectra of chlorophyll for its spectrum is in many respects very like that of a metal-porphyrin. This last note is intended to stress the features of chlorophyll chemistry which parallel those of P-450. 

Figure 11.7 Structures and absorption spectra of chlorophylls a and b schematic view of light harvesting complex. (Data from Protein Data Bank (DO 10.2210/pdb2BHW/pdb))...

Weiss CJR. The 7T-electron structure and absorption spectra of chlorophylls in solution. J. Mol. Spec. 1972 44 37-80. Yaronskaya, Grimm B. Intermediate steps to PChlide. In Chlorophylls and Bacteriochlorophylls Biochemistry, Biophysics, Functions and Applications. Grimm B, Porra R, Rudiger W, Scheer H, eds. 2006. Springer, Dordrecht, The Netherlands, pp. 173-188. Beale SI. Enzymes of chlorophyll biosynthesis. Photosynth. Res. 1999 60 43-73. 

Fig. 9. Absorption spectra of chlorophylls a and b, p-carotene, phycocyanin and phycoerythrin the overlaid spectrum (thick-line) is that of solar-energy distribution at earth s surface.

For the intramolecular vibrational modes, we adopt the data from the site-selection absorption spectra of chlorophyll-a and pheophytin-a in an n-octane matrix at 4.2 K [6]. 

Fig. 17.2. Absorption spectra of chlorophylls a (I) and b (II). Solvent iethyl ether (I) or diethyl ether +1% CCI4 (II)...

Fl 12.31 The absorption spectra of chlorophylls a and b (Atlas R3), the main pigments in plants, in the visible region. Note that the chlorophylls absorb in the orange-red and blue regions and that green light is not absorbed significantly. 

FIGURE 7.5 Electronic absorption spectra of chlorophyll a (—) and pheoph3ftin a (—). 

FIGURE 7.8 Electronic absorption spectra of chlorophyll fl(—) and Mg-phytol-chlorin eg ( ). 

FIG.5. Absorption spectra of chlorophyll-protein FIG.6.Fluorescence emission complexes (CPC) spectra at -196°C of CPC... 

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