Dictionary > Eumelanin


An aggregate of pigment molecules, each made up of cross-linked 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA) polymers, and is responsible for the black or brownish pigmentation of skin, feathers, hair, fur, eyes, scales, etc.
Melanin is a term to refer to a group of pigments produced from the oxidation of tyrosine, followed by polymerization. It is produced by and stored in melanocytes or melanophores. The colours may vary and may be used as a basis for classifying melanin. There are three basic types of melanin: (1) eumelanin, (2) pheomelanin, and (3) neuromelanin.
Eumelanin is the most common and abundant type. It is composed of an aggregate of molecules that render brown or black in colour. Eumelanin polymer is made up of cross-linked 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA) polymers. There are two types of eumelanin, i.e. brown eumelanin and black eumelanin. Apart from the light-absorbing qualities that account for their respective colours, they also differ in the pattern of polymeric bonds. Eumelanin is produced through the process of melanogenesis, which includes a series of catalysed chemical reactions, starting from tyrosine, and with tyrosinase as the key enzyme.
In humans, it accounts for the pigmentation of the skin and hair. In particular, a small quantity of black eumelanin (in the absence of other pigments as well) results in gray hair. A small amount of brown eumelanin (in the absence of other pigments as well) results in blond hair. A defective tyrosinase production leads to the disruption of melanin production (including eumelanin) and therefore results in oculocutaneous albinism.
Word origin: eu– (true, well, good”) + Greek melas (“black, dark”)
See also:

You will also like...

Chromosome Mutations
Chromosome Mutations

Mutations can also influence the phenotype of an organism. This tutorial looks at the effects of chromosomal mutations, ..

DNA - schematic
Genetic Mutations

This tutorial looks at the mutation at the gene level and the harm it may bring. Learn about single nucleotide polymorph..

Human perception in action
Human Perception – Neurology

This tutorial investigates perception as two people can interpret the same thing differently. Know more about human perc..

Gene Pool and Speciation
The Gene Pool and Population Genetics

According to Charles Darwin's theory of natural selection, preferable genes are favored by nature in the gene pool, and ..

Peppered moth ("Biston betularia") melanic and light form
Examples of Natural Selection

Darwin's Finches are an example of natural selection in action. They are an excellent example of the way species' gene p..

Gibberellins and Gibberellic Acid
Gibberellins and Gibberellic Acid

This tutorial describes the role of gibberellin family in plants. Find out the effects of gibberellin on plant growth an..