Final answer:
The Coomassie reagent, specifically Coomassie Brilliant Blue G-250, absorbs at around 595 nm when bound to proteins and at about 465 nm when it is not. A green chromophore would absorb photons in the red and violet wavelengths of the visible spectrum.
Step-by-step explanation:
The Coomassie reagent, which is commonly used in biochemistry labs for protein quantification, absorbs light at specific wavelengths depending on its form. When bound to protein, Coomassie Brilliant Blue G-250, the dye used in the Coomassie reagent, normally absorbs light at a maximum wavelength (Amax) of around 595 nm, which is within the orange region of the visible spectrum. However, when the Coomassie reagent is not bound to protein, it absorbs light at about 465 nm, which is in the blue part of the spectrum. This shift in absorption is due to the binding of the dye to the protein, which causes a change in the dye's electronic structure, as it involves the extended system of conjugated pi bonds. For instance, an absorption peak at 1716 cm-1 (equivalent to a wavelength of approximately 5.86 μm) is indicative of a carbonyl group, a functional group commonly found in various biochemical compounds.
A chromophore that appears green would absorb photons of complementary colors, which, based on the color wheel, are typically in the red and violet wavelengths, or around 400 nm and 800 nm.