Biological pigment

The term pigment ( pigmentum from the Latin color, coloring matter ) denotes the coloring substances in plant, animal and human cells, particularly of the skin as well as surface defects such as hair, feathers, scales (eg on the butterfly wings ), bowls in biology or cuticle. You can of energy (photosynthesis in plants ), oxygen transport, of visual perception in the eye of camouflage, as a signal or protection against UV radiation are used.

Pigments in plants

The main pigments present in plants and algae, which are also responsible for the green color in Embryophyten and green algae are chlorophylls. All plants ( kingdom Plantae Archaeplastida = ) and algae contain chlorophyll a The Archaeplastida be, besides morphological differences, differentiated according to the type of pigments in addition contained in three subgroups, depending on whether additional chlorophyll b, xanthophylls and / or phycobilins are included.

Algae with complex plastids, which come from a endosymbiosis with a red alga, contain instead of chlorophyll b, chlorophyll c most.

The phycobilisomes, the light -harvesting complexes of cyanobacteria, red algae, and the Glaucocystophyceen thekaten amoeba Pauli Ella chromatophora consist of biliproteins. While phycocyanin and allophycocyanin are present in all phycobilisome, phycoerythrin in red algae and cyanobacteria is only - but not all - is formed. Cryptophyceae instead of phycobilisomes contain only a single strongly modified phycoerythrin as a light -harvesting complex.

Also the pigments dissolved in the cell sap anthocyanins and flavones are counted as well as the phlobaphenes, which are embedded in the walls of dead cells.

Pigments in humans and animals

In animals, melanins, carotenoids, guanine, as well as the bile pigments are the most important pigments represents the pigments are including in skin, hair, scales, feathers, or Chitinpanzern. Animal pigments can be concentrated in pigment cells ( chromatophores ) or dissolved in body fluids.

Butterflies generate additional color effects by interference on the scales. Skeletons and shells from calcium carbonate (lime), such as those found in sponges, clams or snails may contain inorganic pigments.

The skin color of mammals arises primarily from melanins. Hemoglobin, the coloring matter of the blood of vertebrates, change through uptake and release of molecular oxygen the color of the iron -hemoglobin complex from red to red-violet. Cause is a structural change at constant oxidation state of II of the iron atom in heme.

At reduced pigment production is called hypopigmentation, with increased hyperpigmentation.

Use

Some farmed organic pigments, such as the intensely colored Indian yellow from the urine of cows were produced directly from plants or animal products. However, they lost by the end of the 19th century, the available synthetic organic pigments increasingly important.