Leaves change color in the fall because their chromophores (chlorophyll molecules) break down and stop absorbing red and blue light.[1]
A chromophore is a molecule which absorbs light at a particular wavelength and emits 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'. Many molecules in nature are chromophores, including chlorophyll, the molecule responsible for the green colors of leaves.
The color that is seen by our eyes is that of the light not absorbed by the reflecting object within a certain wavelength spectrum of visible light. The chromophore indicates a region in the molecule where the energy difference between two separate molecular orbitals falls within the range of the visible spectrum (or in informal contexts, the spectrum under scrutiny). Visible light that hits the chromophore can thus be absorbed by exciting an electron from its ground state into an excited state. In biological molecules that serve to capture or detect light energy, the chromophore is the moiety that causes a conformational change in the molecule when hit by light.
Healthy plants are perceived as green because chlorophyll absorbs mainly the blue and red wavelengths but green light, reflected by plant structures like cell walls, is less absorbed.[2]The eleven conjugated double bonds that form the chromophore of the β-carotene molecule are highlighted in red.
^Kräutler, Bernhard (26 February 2016). "Breakdown of Chlorophyll in Higher Plants—Phyllobilins as Abundant, Yet Hardly Visible Signs of Ripening, Senescence, and Cell Death". Angew. Chem. Int. Ed. 4882 (55): 4882–4907. doi:10.1002/anie.201508928. PMC 4950323. PMID 26919572.
^Virtanen, Olli; Constantinidou, Emanuella; Tyystjärvi, Esa (2020). "Chlorophyll does not reflect green light – how to correct a misconception". Journal of Biological Education. 56 (5): 1–8. doi:10.1080/00219266.2020.1858930.
A chromophore is a molecule which absorbs light at a particular wavelength and emits color as a result. Chromophores are commonly referred to as colored...
tool in many forms of biology due to its ability to form an internal chromophore without requiring any accessory cofactors, gene products, or enzymes...
(chrōma) 'colour') is a group of atoms attached to a chromophore which modifies the ability of that chromophore to absorb light. They themselves fail to produce...
Larry R. Dalton (2001). "Low Vπ Electrooptic Modulators from CLD-1: Chromophore Design and Synthesis, Material Processing, and Characterization". Chem...
up the chromophore. This changes the molecule into a different substance that either does not contain a chromophore or contains a chromophore that does...
up the chromophore. This changes the molecule into a different substance that either does not contain a chromophore, or contains a chromophore that does...
α-allophycocyanin requires an exogenous protein, known as a lyase, to attach the chromophore, phycocyanobilin. Phycocyanobilin is not present in mammalian cells....
range of 550-650 nm. mCherry belongs to the group of fluorescent protein chromophores used as instruments to visualize genes and analyze their functions in...
form the basis of chromophores, which are light-absorbing parts of a molecule that can cause a compound to be colored. Such chromophores are often present...
indicators on litmus owe their properties to a 7-hydroxyphenoxazone chromophore. Some fractions of litmus were given specific names including erythrolitmin...
isolated from an Actinomycete in 1992, comprising an ansa-bridged enediyne chromophore (shown) as well as an apoprotein that serves to stabilize the toxin in...
Retinal (also known as retinaldehyde) is a polyene chromophore. Retinal, bound to proteins called opsins, is the chemical basis of visual phototransduction...
the reaction centers, proteins that contain photosynthetic pigments or chromophores. In plants, these proteins are chlorophylls (a porphyrin derivative that...
In a reactive dye, a chromophore (an atom or group whose presence is responsible for the colour of a compound) contains a substituent that reacts with...
purple, and orange pigments, all through intentional addition of a chromophore in the trigonal bipyramidal coordination environment. The discovery of...
replenishes the molecule retinal for its use in vision. Retinal is the chromophore of most visual opsins, meaning it captures the photons to begin the phototransduction...
Phytochromes consist of a protein, covalently linked to a light-sensing bilin chromophore. The protein part comprises two identical chains (A and B). Each chain...
first features the chromium chromophore that creates the red color of ruby, combined with the iron + titanium chromophore that produces the blue color...
known as Witt theory stated that a colored dye had two components, a chromophore which imparts color by absorbing light in the visible region (some examples...
employed as an IR-emitting chromophore for in vivo imaging. In contrast to fluorescent proteins which form their chromophore through posttranslational...
they absorb light. The term is generally applied to the non-protein chromophore moiety of photosensitive chromoproteins, such as the pigments involved...
LWS opsins from 500-570 nm. However, some fish that use alternative chromophores can extend their LWS opsin sensitivity to 625 nm. The popular belief...
out essential functions. For example, the 11-cis-retinal isomer is the chromophore of rhodopsin, the vertebrate photoreceptor molecule. Rhodopsin is composed...
approaches used in the past to enhance nonlinearities include extending chromophore π-systems, adjusting bond length alternation, inducing intramolecular...
phycobiliproteins, it is composed of a protein part covalently binding chromophores called phycobilins. In the phycoerythrin family, the most known phycobilins...
polarizability of the local chromophore environment as well as providing additional electron density into the chromophore. "Venus" contains a novel amino...
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