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In biology, pigment is any material resulting in color in plant or animal cells which is the result of selective absorption. Some biological material has so-called structural color, which is the result of selective reflection or iridescence, usually done with multilayer structures. Unlike structural color, pigment color is the same for all viewing angles. Nearly all types of cells, such as skin, eyes, fur and hair contain pigment. Butterfly wings typically contain structural color, although many of them contain pigment as well. Creatures that have deficient pigmentation are called albinos.Because pigment color is the result of selective absorption, there is no such thing as white pigment. A white object is simply a diffuse reflecting object which does not contain any pigment.
In the coloring of paint, ink, plastic, fabric and other material, a pigment is a dry colorant, usually an insoluble powder. There are both natural and synthetic pigments, both organic and inorganic ones. Pigments work by selectively absorbing some parts of the visible spectrum (see light) whilst reflecting others.
A distinction is usually made between a pigment, which is insoluble, and a dye, which is either a liquid, or is soluble. There is no well-defined dividing line between pigments and dyes, however, and some coloring agents are used as both pigments and dyes. In some cases, a pigment will be made by precipitating a soluble dye with a metallic salt. The resulting pigment is called a "lake".
1 List of pigments
1.1 Heme/ PorphyrinA porphyrin is a heterocyclic macrocycle made from 4 pyrrole subunits linked on opposite sides through 4 methine bridges. The macrocycle, therefore, is completely aromatic, unlike the related corrins or chlorins. Types of porphyrins Porphyrins combine rea based
- ChlorophyllChlorophyll is the green photosynthetic pigment present in chloroplasts, which provides the energy necessary for photosynthesis. The intense green color of chlorophyll is due to its strong absorbence in the red and blue regions of the electromagnetic spec
- BilirubinBilirubin is a yellow breakdown product of haem heme in American English). Haem is a special ring shaped molecule that is found in haemoglobin. The haem ring holds the iron atoms of haem and is essential to the oxygen carrying capacity of blood. Bilirubin
- HemocyaninThe hemocyanins (also spelled haemocyanins are respiratory proteins containing two copper atoms that reversibly bind oxygen by changing between the colorless Cu(I) deoxygenated form and the blue Cu(II) oxygenated form. They are found in the blood of some
- HemoglobinHaemoglobin ( BE) or hemoglobin ( AE), is the iron-containing oxygen-transport metalloprotein in the red cells of the blood in mammals and other animals. The molecule consists of globin, the apoprotein, and four haem groups, an organic molecule with an ir
- MyoglobinMyoglobin is a single-chain protein of 153 amino acids, containing a heme ( iron-containing porphyrin) group in the center. With a molecular weight (MW) of 16,700, it is the primary oxygen-carrying pigment of muscle tissues. Unlike the blood-borne hemoglo
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