Absorbance maximal

A low potential electron carrier, the fluorescent factor F420 [37333-48-5, 64885-97-8] (29) (it absorbs maximally at 420 nm), possessing a... 

Phycochrome a, extracted from Tolypothrix distorta, Phormidium luridum, Nostoc muscorum and Anacystis nidulans, has one form absorbing maximally at about 590 nm, formed in red light, and another one absorbing at 570 nm, formed in yellow-green and blue-green light. 

Phycochrome b, also found in Tolypothrix, occurs in two forms absorbing maximally at 510 and 570 nm respectively, and produced in yellow-green and blue-green light respectively. 

Bradford reagent contains the dye Coomassie blue G-250 in an acidic solution. The dye binds to protein, yielding a blue colour that absorbs maximally at 595 nm Copper-containing reagent that, when reduced by protein, reacts with bicinchonic acid yielding a complex that displays an absorbance maximum at 562 nm Essentially involves initial precipitation of protein out of solution by addition of trichloroacetic acid. The protein precipitate is redissolved in NaOH and the Lowry method of protein determination is then performed Interaction of silver with protein - very sensitive method... 

Protein determination procedures using bicinchonic acid were developed by Pierce Chemicals, who hold a patent on the product. The procedure entails the use of a copper-based reagent containing bicinchonic acid. Upon incubation with a protein sample, the copper is reduced. In the reduced state it reacts with bicinchonic acid, yielding a purple colour that absorbs maximally at 562 nm. 

FIGURE 49-4 Intermediates formed after photic bleaching of vertebrate rhodopsin. Numbers in parentheses are wavelengths of light (in nanometers) absorbed maximally by the individual intermediates. 

Rods absorb maximally at 509 nm, blue-sensitive cones at 420 nm, green-sensitive cones at 530 nm and red-sensitive cones at 565 nm. Colour blindness results from mutations that occur in the genes for the three different colour-sensitive opsin molecules. 

The complex with anthrone absorbs maximally at 625 nm. The concentration of lactose is determined from a standard curve prepared using a range of lactose concentrations. 

The free dye (M) has an absorption maximum at 520 nm while Ca M absorbs maximally at 480 nm. The concentration of Ca2 + can be calculated from a standard curve in which A480 is plotted as a function of [Ca2+] or preferably from a standard curve of (A520 — A480) as a function of [Ca2+] which is less curved and more sensitive (Figure 5.9). Using this method, the [Ca2+] in milk was found to be 2.53-3.4 mM and appears to be 0.8 mM higher than that determined by the other methods. 

The reduced coenzymes NADH and NADPH were characterized by a new light-absorption band at 340 nm. This is not present in the oxidized forms, which absorb maximally at 260 nm (Fig. 15-2). The reduced forms are stable in air, but their reoxidation was found... 

In solution, 1 1-em-retinal absorbs maximally near 380 nm, but in rhodopsin the peak is at 500 nm (fig. S2.5). The absorption spectrum of rhodopsin is essentially identical to the spectrum of the sensitivity of the rod cells (after correction for absorption in the cornea and lens). The per-... 

To explore the changes in rhodopsin that precede release of all-tram-retinal from the protein, Torn Yoshizawa and Wald measured the optical absorbance changes that occurred when they illuminated rhodopsin at low temperatures. At 77 K, illumination caused the absorption band of the rhodopsin to shift from 500 to 543 nm. The product of this transformation is now called bathorhodopsin. Bathor-hodopsin is stable indefinitely in the dark at 77 K, but if it is warmed above about 130 K it decays spontaneously to a species that absorbs maximally at 497 nm. This is called lumirhodopsin. If the sample is warmed further to about... 

Azidoadenine derivatives (e.g. Czamecki et al., 1979) have proved exceptionally useful and they absorb maximally at 280 nm. These molecules bear a structural resemblance to carbonylazides, which yield extremely reactive nitrenes. 

The absorption and rotatory dispersion of the complexes of ovotransferrin and serum transferrin with Mn3+ and Cu2+ were compared to those of the ferric complexes (Fig. 5 and Fig. 9). The Mn3+ complexes absorbed maximally at 429 mp and gave rise to positive Cotton effects closely similar in both transferrins. The Cu2+ complexes absorbed maximally at 436 mp but this absorption, in contrast to those of the Fe3+ and Mn 3+ complexes, was not optically active. It was concluded that copper does... 

Manganese in the human is also thought to be absorbed maximally in the duodenum in the II valence state. Therefore, as with manganese uptake by plants, the pH of the upper gastro-intestinal tract might be expected to be of importance in the absorption of manganese by the human. 

The biochemistry that mediates photon absorption in the disk membranes and closing of the ionic channels in the plasma membrane is summarized in Fig. 2 and discussed in detail in reviews that provide access to the original literature (Helmreich and Hofmann, 1996 Menon et al, 2001 Hamm 1998, 2001 Bunemann and Hosey, 1999 Krupnick and Benovic, 1998). In the dark (inactive) state, rhodopsin (R) contains a covalently bound 11 -cis retinal chromophore buried within the protein core. In rhodopsin, the chromophore absorbs maximally around 500 nm, and absorption of a photon isomerizes the retinal to the all-trans form within about 200 fs (Peteanu et al, 1993) with a quantum efficiency of 0.67 (Dartnall, 1972). The change in chromophore shape creates strain, and subsequent thermal relaxation of both chromophore... 

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