What is Melanin?

Melanin is a complex polymer derived from the amino acid tyrosine. Melanin is responsible for determining skin and hair colour and is present in the skin to varying degrees, depending on how much a population has been exposed to the sun historically.

Melanin synthesis

Numerous steps are involved in the biosynthesis of melanin. The first step is catalysis of the chemical L-3,4-dihydroxyphenylalanine by tyrosinase. A lack of tyrosine can lead to albinism. Tyrosine is only found in a specialized cells called melanocytes, inside which tiny granules of melanin pigment are contained in vesicles called melanosomes.

These melanosomes leave the melanocytes and move into other cells in the epidermis. Mostly brown or black in colour, melanin deposits determine the skin pigment which varies depending on the number and distribution of the melanosomes. Aside from determining skin colour, the light absorbent melanin protects the DNA against UV radiation from the sun and it is considered a potential candidate in melanoma treatment.

Melanin is found in several areas of the human body including:

  • Skin where it provides skin color
  • Hair
  • Pupils or irises of the eyes
  • Stria vascularis of the inner ear
  • Areas of the brain, the substantia nigra and locus coeruleus
  • The medulla and zona reticularis of the adrenal gland

Types of melanin

Some of the different types of melanin include eumelanin, pheomelanin and neuromelanin. Eumelanin is found in the hair, skin and dark areas around the nipples. It is particularly abundant among black populations and provides black and brown pigment to the hair, skin and eyes.

When eumelanin is present only in small amounts, hair may be blonde.

Pheomelanin is also found in the hair and skin. This type of melanin provides pink and red colors and is the main pigment found among red-haired individuals. This type of melanin is not as protective against UV- radiation induced cancer as eumelanin.

Neuromelanin is a form of melanin found in different areas of the brain and loss of this melanin may cause several neurological disorders.

Reviewed by Sally Robertson, BSc

Further Reading

Last Updated: Sep 8, 2014

Advertisement

Comments

  1. ^.^
    Luke Cooper Luke Cooper United States says:

    We should be learning about this in school! Laughing I hate how our school system doesn't tell us about this.

    • Pamela Spiro Wagner Pamela Spiro Wagner United States says:

      Yeah, instead of teaching people that black people are all "dangerous" and even if unarmed might be like "hulk hogan" they should teach that black skin with its eumelanin protects people from cancer better than fair and pink skin...Much better to provide accurate information than to rabble rouse or let fear rule the day...

      • Luke Powell Luke Powell United Kingdom says:

        No-body ever said black people were dangerous

      • paul middleton paul middleton United Kingdom says:

        In society we see the black man kill the black man no love there you hate each other. i dont know why this has come about. if it is due to the western world i dont think so because we see it abroad with gorilla gangs chipping up there people with massive knives. ransacking there peoples homes and killing them for there goods. this could be the work of satan. we all have the ability to be good people if we just chose it melanin or not. we can all be saved by jesus. i have heard from a guy in costa rika called nature boy and he says white people are genetically retarded due to them not having melanin.
        in the days of babylon. they had all people and races around the world join there society and they was so proud they built a big tower that reached the sky. when god saw this he came own split the people up again and change the way they talked and called the language babel for some reason white people dont have melanin. i dont know what why this effects us if any.  but this is how god made us. so we are suppose to be this way. we can all serve the higher self.we are all gods children.

    • Shaka Davis Shaka Davis United States says:

      You're in America.. you don't learn about black people.

    • Limpieza Facial Limpieza Facial Mexico says:

      no doubt!

    • josette turner josette turner United States says:

      that's why reading is more important than watching tv.

  2. Yishibah Baht Gavriel Yishibah Baht Gavriel United Kingdom says:

    This subject can be taught not just as a biochemistry subject but in the context of bio-physiology and the powerful benefits that the melanin has for dark skinned people. They need also to include the psycho-social and historical dynamics.

  3. Alex Merritt Alex Merritt United States says:

    I wonder if this Doctor looked in the mirror lately?  She states melanin is found among blacks when clearly she appears to be eastern indian.  India, Mexico, middle east, Asia, and S. America are full of melanin people.  SMH.

  4. Alex Merritt Alex Merritt United States says:

    Look mendelian genetics.  Melanin is a dominate gene.

  5. Deepthi Suniana Deepthi Suniana India says:

    Hello sir i have a red hair is there any medicine or cure to  turn into black hair

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News-Medical.Net.
Post a new comment
Post