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- https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Organic_Chemistry_(OpenStax)/14%3A_Conjugated_Compounds_and_Ultraviolet_Spectroscopy/14.09%3A_Conjugation_Color_and_the_Chemistry_of_VisionWhy are some organic compounds colored while others are not? β-Carotene, the pigment in carrots, is yellow-orange, for instance, while cholesterol is colorless. The answer involves both the chemical s...Why are some organic compounds colored while others are not? β-Carotene, the pigment in carrots, is yellow-orange, for instance, while cholesterol is colorless. The answer involves both the chemical structures of colored molecules and the way we perceive light.
- https://chem.libretexts.org/Workbench/LCDS_Organic_Chemistry_OER_Textbook_-_Todd_Trout/14%3A_Conjugated_Compounds_and_Ultraviolet_Spectroscopy/14.10%3A_Conjugation_Color_and_the_Chemistry_of_VisionThe key substance for vision is dietary β-carotene, which is converted to vitamin A by enzymes in the liver, oxidized to an aldehyde called 11-trans-retinal, and then isomerized by a change in geometr...The key substance for vision is dietary β-carotene, which is converted to vitamin A by enzymes in the liver, oxidized to an aldehyde called 11-trans-retinal, and then isomerized by a change in geometry of the C11–C12 double bond to produce 11-cis-retinal. Isomerization of rhodopsin is accompanied by a change in molecular geometry, which in turn causes a nerve impulse to be sent through the optic nerve to the brain, where it is perceived as vision.
- https://chem.libretexts.org/Courses/Smith_College/CHM_223_Chemistry_III%3A_Organic_Chemistry_(2024)/08%3A_Conjugated_Compounds_and_Ultraviolet_Spectroscopy/8.10%3A_Conjugation_Color_and_the_Chemistry_of_VisionAlthough its wavelength response is restricted to 400-800 nm, but its degree of sensitivity is such that a fully dark-adapted eye can clearly detect objects in light so dim as to correspond to a light...Although its wavelength response is restricted to 400-800 nm, but its degree of sensitivity is such that a fully dark-adapted eye can clearly detect objects in light so dim as to correspond to a light input over the retina of only about 10,000 quanta per second - one light quantum per three minutes per receptor cell in the retina! It absorbs most strongly in the blue-green region of the visible spectrum (λ max = 500nm) and is essentially unaffected by the far-red end of the spectrum.
- https://chem.libretexts.org/Courses/can/CHEM_232_-_Organic_Chemistry_II_(Puenzo)/01%3A_Conjugated_Compounds_and_Ultraviolet_Spectroscopy/1.09%3A_Conjugation_Color_and_the_Chemistry_of_VisionFigure \PageIndex2: The key substance for vision is dietary β-carotene, which is converted to vitamin A by enzymes in the liver, oxidized to an aldehyde called 11-trans-retinal, and then isomeri...Figure \PageIndex2: The key substance for vision is dietary β-carotene, which is converted to vitamin A by enzymes in the liver, oxidized to an aldehyde called 11-trans-retinal, and then isomerized by a change in geometry of the C11–C12 double bond to produce 11-cis-retinal.
- https://chem.libretexts.org/Courses/Brevard_College/CHE_202%3A_Organic_Chemistry_II/05%3A_Structural__Determination_I/5.07%3A_Conjugation_Color_and_the_Chemistry_of_VisionOpsin does not absorb visible light, but when it bonded with 11-cis-retinal by its lysine side-chain to from rhodopsin, the new molecule has a very broad absorption band in the visible region of the s...Opsin does not absorb visible light, but when it bonded with 11-cis-retinal by its lysine side-chain to from rhodopsin, the new molecule has a very broad absorption band in the visible region of the spectrum.[2][3] By removing the oxygen atom form the retinal and two hydrogen atom form the free amino group of the lysine, the linkage show on the picture above is formed, and it is called Schiff base.
- https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Organic_Chemistry_(Morsch_et_al.)/14%3A_Conjugated_Compounds_and_Ultraviolet_Spectroscopy/14.09%3A_Conjugation_Color_and_the_Chemistry_of_VisionAlthough its wavelength response is restricted to 400-800 nm, but its degree of sensitivity is such that a fully dark-adapted eye can clearly detect objects in light so dim as to correspond to a light...Although its wavelength response is restricted to 400-800 nm, but its degree of sensitivity is such that a fully dark-adapted eye can clearly detect objects in light so dim as to correspond to a light input over the retina of only about 10,000 quanta per second - one light quantum per three minutes per receptor cell in the retina! It absorbs most strongly in the blue-green region of the visible spectrum (λ max = 500nm) and is essentially unaffected by the far-red end of the spectrum.
- https://chem.libretexts.org/Courses/Brevard_College/LNC_216_CHE/08%3A_Chemistry_of_color/8.04%3A_Conjugation_Color_and_the_Chemistry_of_VisionAlthough its wavelength response is restricted to 400-800 nm, but its degree of sensitivity is such that a fully dark-adapted eye can clearly detect objects in light so dim as to correspond to a light...Although its wavelength response is restricted to 400-800 nm, but its degree of sensitivity is such that a fully dark-adapted eye can clearly detect objects in light so dim as to correspond to a light input over the retina of only about 10,000 quanta per second - one light quantum per three minutes per receptor cell in the retina! It absorbs most strongly in the blue-green region of the visible spectrum (λ max = 500nm) and is essentially unaffected by the far-red end of the spectrum.
- https://chem.libretexts.org/Workbench/SC_149%3A_Cosmetic_Chemistry/13%3A_Sensory_PerceptionA major role of sensory receptors is to help us learn about the environment around us, or about the state of our internal environment. Stimuli from varying sources, and of different types, are receive...A major role of sensory receptors is to help us learn about the environment around us, or about the state of our internal environment. Stimuli from varying sources, and of different types, are received and changed into the electrochemical signals of the nervous system. This occurs when a stimulus changes the cell membrane potential of a sensory neuron. The stimulus causes the sensory cell to produce an action potential that is relayed into the central nervous system (CNS).
- https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Map%3A_Physical_Chemistry_for_the_Biosciences_(Chang)/15%3A_Photochemistry_and_Photobiology/15.03%3A_VisionVision is such an everyday occurrence that we seldom stop to think and wonder how we are able to see the objects that surround us. Yet the vision process is a fascinating example of how light can prod...Vision is such an everyday occurrence that we seldom stop to think and wonder how we are able to see the objects that surround us. Yet the vision process is a fascinating example of how light can produce molecular changes. The retina contain the molecules that undergo a chemical change upon absorbing light, but it is the brain that actually makes sense of the visual information to create an image.
- https://chem.libretexts.org/Courses/Smith_College/Organic_Chemistry_(LibreTexts)/14%3A_Conjugated_Compounds_and_Ultraviolet_Spectroscopy/14.10%3A_Conjugation_Color_and_the_Chemistry_of_VisionAlthough its wavelength response is restricted to 400-800 nm, but its degree of sensitivity is such that a fully dark-adapted eye can clearly detect objects in light so dim as to correspond to a light...Although its wavelength response is restricted to 400-800 nm, but its degree of sensitivity is such that a fully dark-adapted eye can clearly detect objects in light so dim as to correspond to a light input over the retina of only about 10,000 quanta per second - one light quantum per three minutes per receptor cell in the retina! It absorbs most strongly in the blue-green region of the visible spectrum (λ max = 500nm) and is essentially unaffected by the far-red end of the spectrum.
- https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Organic_Chemistry_II_(Morsch_et_al.)/14%3A_Conjugated_Compounds_and_Ultraviolet_Spectroscopy/14.09%3A_Conjugation_Color_and_the_Chemistry_of_VisionAlthough its wavelength response is restricted to 400-800 nm, but its degree of sensitivity is such that a fully dark-adapted eye can clearly detect objects in light so dim as to correspond to a light...Although its wavelength response is restricted to 400-800 nm, but its degree of sensitivity is such that a fully dark-adapted eye can clearly detect objects in light so dim as to correspond to a light input over the retina of only about 10,000 quanta per second - one light quantum per three minutes per receptor cell in the retina! It absorbs most strongly in the blue-green region of the visible spectrum (λ max = 500nm) and is essentially unaffected by the far-red end of the spectrum.
