Pigments (from lat. pigmentum - paint) - coloring organic matter complex chemical structures. Widely distributed in nature, found in cells, tissues and fluids organisms, giving them the appropriate color.
The most important pigment organisms are porphyrins (see), chromoproteids, melanin (see), carotenoids (see), anthocyanins and flavones (see). The chromoproteids-complex proteins, including simple protein and painted prosthetic group pigments non-protein nature. Such chromoproteids as red pigments blood and muscles [hemoglobin (see) and myoglobin], P. green blood worms (chloroquin), catalase, cytochromes (see) and others, as prosthetic group includes porphyrin metal derivatives in the form zhelezovanadievoj complex (heme). Green P. plant chlorophyll, also related to the chromoproteids, contain a molecule magnitosfernoi complex (forbid). On the chemical nature to the chlorophyll close bakteriokhlorofill located in the body of photosynthetic bacteria.
At destruction in the animal organism of hemoglobin, myoglobin and cytochromes are formed bile pigment (see), pigments feces and urine - stercobilin and urobilin (see).
To chromoproteids, not containing in the structure of heme are brown iron-containing protein - hemerythrin, located in the cells of abdominal fluid annelids, and a dark blue or greenish-blue hemocyanine, copper-containing proteins haemolymph invertebrates. From the amino acid tyrosine in the animal organism are brown-black P. hair, skin and body iris - melanin. To P. animals is also lipofuscin (see), which consists of carbohydrate, lipid and protein components.
In the vegetable world have a significant distribution carotenoids, yellow and orange pigments related to unsaturated hydrocarbons. Many P. microorganisms according to its chemical structure are carotenoids, and anthocyanin.
Extremely important biological role of a number of P. Hemoglobin, chloroquin and some other chromoproteids are carriers of oxygen. Myoglobin creates a certain reserve of oxygen in the muscles, chlorophylls are involved in photosynthesis. Cytochromes, catalase and other P. enzymes are biological oxidation. Carotenoids, apparently, are involved in respiration of plants and are sources for the formation of vitamin a and visual purple. Anthocyanins and flavones, painting the fruits, leaves and flowers of plants, also perform light protection function. Cm. also, Pigmentary exchange.