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A chromophore is a molecule which absorbs light at a particular wavelength and reflects color as a result. Chromophores are commonly referred to as colored molecules for this reason. The word is derived from Ancient Greek χρῶμᾰ (chroma) 'color' and -φόρος (phoros) 'carrier of'.
An examples of negative solvatochromism is provided by 4-(4 ′ -hydroxystyryl)- N -methylpyridinium iodide , which is red in 1-propanol , orange in methanol , and yellow in water . Positive solvatochromism corresponds to a bathochromic shift (or red shift) with increasing solvent polarity.
The retinal chromophore differs from the animal 11-cis form and is an all-trans retinal isomer at the ground state, which isomerizes to 13-cis upon light activation; the chromophore is also known as microbial-type chromophore. Examples are bacterial sensory rhodopsins, channelrhodopsins, bacteriorhodopsins, halorhodopsins, proteorhodopsins ...
Haem, for example, is a biochrome responsible for the red appearance of blood. It is found primarily in red blood cells (erythrocytes), which are generated in bone marrow throughout the life of an organism, rather than being formed during embryological development. Therefore, erythrocytes are not classified as chromatophores.
Visual phototransduction is the sensory transduction process of the visual system by which light is detected by photoreceptor cells (rods and cones) in the vertebrate retina.A photon is absorbed by a retinal chromophore (each bound to an opsin), which initiates a signal cascade through several intermediate cells, then through the retinal ganglion cells (RGCs) comprising the optic nerve.
The apoprotein with its chromophore is called phycocyanin, phycoerythrin, and allophycocyanin, respectively. They often occur as hexamers of α and β subunits (α 3 β 3) 2. They enhance the amount and spectral window of light absorption and fill the "green gap", which occurs in higher plants. [17]
A donor chromophore, initially in its electronic excited state, may transfer energy to an acceptor chromophore through nonradiative dipole–dipole coupling. [2] The efficiency of this energy transfer is inversely proportional to the sixth power of the distance between donor and acceptor, making FRET extremely sensitive to small changes in ...
Unlike negative staining, positive staining uses basic dyes to color the specimen against a bright background. While chromophore is used for both negative and positive staining alike, the type of chromophore used in this technique is a positively charged ion instead of a negative one. The negatively charged cell wall of many microorganisms ...