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Crustacyanin
Crustacyanin is a carotenoprotein biological pigment found in the exoskeleton of lobsters and responsible for their blue colour. β-Crustacyanin (β-CR), is composed of two stacked astaxanthin carotenoids that absorb at λ = 580–590 nm (2.10–2.14 eV). α-crustacyanin (α-CR) is an assembly of eight β-CR protein dimers. It is a 320 kDa (atomic mass The atomic mass (''m''a or ''m'') is the mass of an atom. Although the SI unit of mass is the kilogram (symbol: kg), atomic mass is often expressed in the non-SI unit dalton (symbol: Da) – equivalently, unified atomic mass unit (u). 1&n ...) complex containing 16 astaxanthin molecules. Although the β-CR dimer has a peak wavelength of 580 nm, α-CR exhibits a bathochromic shift to 632 nm; the mechanism and function of the additional wavelength shift is not understood. References {{reflist Biological pigments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Pigment
Biological pigments, also known simply as pigments or biochromes, are substances produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigments. Many biological structures, such as skin, eyes, feathers, fur and hair contain pigments such as melanin in specialized cells called chromatophores. In some species, pigments accrue over very long periods during an individual's lifespan. Pigment color differs from structural color in that it is the same for all viewing angles, whereas structural color is the result of selective reflection or iridescence, usually because of multilayer structures. For example, butterfly wings typically contain structural color, although many butterflies have cells that contain pigment as well. Biological pigments See conjugated systems for electron bond chemistry that causes these molecules to have pigment. * Heme/porphyrin-based: chlorophyll, bilirubin, hem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lobster
Lobsters are a family (Nephropidae, synonym Homaridae) of marine crustaceans. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs have claws, including the first pair, which are usually much larger than the others. Highly prized as seafood, lobsters are economically important and are often one of the most profitable commodities in coastal areas they populate. Commercially important species include two species of '' Homarus'' from the northern Atlantic Ocean and scampi (which look more like a shrimp, or a "mini lobster")—the Northern Hemisphere genus ''Nephrops'' and the Southern Hemisphere genus '' Metanephrops''. Distinction Although several other groups of crustaceans have the word "lobster" in their names, the unqualified term "lobster" generally refers to the clawed lobsters of the family Nephropidae. Clawed lobsters are not closely related to spiny lobsters or slipper lobsters, which have no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astaxanthin
Astaxanthin is a keto- carotenoid within a group of chemical compounds known as terpenes. Astaxanthin is a metabolite of zeaxanthin and canthaxanthin, containing both hydroxyl and ketone functional groups. It is a lipid-soluble pigment with red coloring properties, which result from the extended chain of conjugated (alternating double and single) double bonds at the center of the compound. Astaxanthin is produced naturally in the freshwater microalgae ''Haematococcus pluvialis'' and the yeast fungus ''Xanthophyllomyces dendrorhous'' (also known as ''Phaffia rhodozyma''). When the algae are stressed by lack of nutrients, increased salinity, or excessive sunshine, they create astaxanthin. Animals who feed on the algae, such as salmon, red trout, red sea bream, flamingos, and crustaceans (shrimp, krill, crab, lobster, and crayfish), subsequently reflect the red-orange astaxanthin pigmentation. Astaxanthin is used as a dietary supplement for human, animal, and aquaculture co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Dimer
In biochemistry, a protein dimer is a macromolecular complex formed by two protein monomers, or single proteins, which are usually non-covalently bound. Many macromolecules, such as proteins or nucleic acids, form dimers. The word ''dimer'' has roots meaning "two parts", '' di-'' + '' -mer''. A protein dimer is a type of protein quaternary structure. A protein homodimer is formed by two identical proteins. A protein heterodimer is formed by two different proteins. Most protein dimers in biochemistry are not connected by covalent bonds. An example of a non-covalent heterodimer is the enzyme reverse transcriptase, which is composed of two different amino acid chains. An exception is dimers that are linked by disulfide bridges such as the homodimeric protein NEMO. Some proteins contain specialized domains to ensure dimerization (dimerization domains) and specificity. The G protein-coupled cannabinoid receptors have the ability to form both homo- and heterodimers with several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Mass Unit
The dalton or unified atomic mass unit (symbols: Da or u) is a non-SI unit of mass widely used in physics and chemistry. It is defined as of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at rest. The atomic mass constant, denoted ''m''u, is defined identically, giving . This unit is commonly used in physics and chemistry to express the mass of atomic-scale objects, such as atoms, molecules, and elementary particles, both for discrete instances and multiple types of ensemble averages. For example, an atom of helium-4 has a mass of . This is an intrinsic property of the isotope and all helium-4 atoms have the same mass. Acetylsalicylic acid (aspirin), , has an average mass of approximately . However, there are no acetylsalicylic acid molecules with this mass. The two most common masses of individual acetylsalicylic acid molecules are , having the most common isotopes, and , in which one carbon is carbon-13. The molecular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathochromic Shift
Bathochromic shift (from Greek βαθύς ''bathys'', "deep"; and χρῶμα ''chrōma'', "color"; hence less common alternate spelling "bathychromic") is a change of spectral band position in the absorption, reflectance, transmittance, or emission spectrum of a molecule to a longer wavelength (lower frequency). Because the red color in the visible spectrum has a longer wavelength than most other colors, the effect is also commonly called a '' red shift''. Hypsochromic shift is a change to shorter wavelength (higher frequency). Conditions It can occur because of a change in environmental conditions: for example, a change in solvent polarity will result in solvatochromism. A series of structurally-related molecules in a substitution series can also show a bathochromic shift. Bathochromic shift is a phenomenon seen in ''molecular'' spectra, not ''atomic'' spectra; it is thus more common to speak of the movement of the peaks in the spectrum rather than lines. :\Delta\lambda = ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John R
John R. (born John Richbourg, August 20, 1910 - February 15, 1986) was an American radio disc jockey who attained fame in the 1950s and 1960s for playing rhythm and blues music on Nashville radio station WLAC. He was also a notable record producer and artist manager. Richbourg was arguably the most popular and charismatic of the four announcers at WLAC who showcased popular African-American music in nightly programs from the late 1940s to the early 1970s. (The other three were Gene Nobles, Herman Grizzard, and Bill "Hoss" Allen.) Later rock music disc jockeys, such as Alan Freed and Wolfman Jack, mimicked Richbourg's practice of using speech that simulated African-American street language of the mid-twentieth century. Richbourg's highly stylized approach to on-air presentation of both music and advertising earned him popularity, but it also created identity confusion. Because Richbourg and fellow disc jockey Allen used African-American speech patterns, many listeners thoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
