Que é Melanina?

Pelo Dr. Ananya Mandal, DM

A Melanina é um polímero complexo derivado da tirosina do ácido aminado. A Melanina é responsável para determinar a cor da pele e do cabelo e esta presente na pele em diferentes graus, segundo quanto uma população foi expor ao sol historicamente.

Síntese da Melanina

As etapas Numerosas sãas na biosíntese da melanina. A primeira etapa sido catálise do produto químico L-3,4-dihydroxyphenylalanine pelo tyrosinase. Uma falta da tirosina pode conduzir ao albinismo. A Tirosina é encontrada somente no as pilhas especializadas chamadas os melanocytes, dentro de que os grânulo minúsculos do pigmento da melanina são contidos nas vesículas chamadas melanosomes.

Estes melanosomes saem dos melanocytes e movem-se em outras pilhas na epiderme. Na Maior Parte marrom ou preto na cor, depósitos da melanina determine o pigmento da pele que varia segundo o número e a distribuição dos melanosomes. Com exceção de determinar a cor de pele, a melanina absorvente clara protege o ADN contra a radiação UV do sol e considera-se um candidato potencial no tratamento da melanoma.

A Melanina é encontrada em diversas áreas de incluir do corpo humano:

  • Pele onde fornece a cor da pele
  • Cabelo
  • Alunos ou íris dos olhos
  • Vascularis do Stria da orelha interna
  • Áreas do cérebro, do negro do substantia e do coeruleus do locus
  • Os reticularis da medula e do zona da glândula ad-renal

Tipos de melanina

Alguns dos tipos diferentes de melanina incluem o eumelanin, o pheomelanin e o neuromelanin. Eumelanin é encontrado no cabelo, na pele e nas áreas da obscuridade em torno dos bocais. É particularmente abundante entre populações pretas e fornece o pigmento preto e marrom ao cabelo, à pele e aos olhos.

Quando o eumelanin esta presente somente nas pequenas quantidades, o cabelo pode ser louro.

Pheomelanin é encontrado igualmente no cabelo e na pele. Este tipo de melanina fornece cores cor-de-rosa e vermelhas e é o pigmento principal encontrado entre indivíduos ruivos. Este tipo de melanina não é como protector contra radiação UV o cancro induzido como o eumelanin.

Neuromelanin é um formulário da melanina encontrado em áreas diferentes do cérebro e a perda desta melanina pode causar diversas desordens neurológicas.

Revisto por Sally Robertson, BSc

Fontes

  1. http://www.gematria-test-lab.com/pdf/theimportant [1] .pdf
  2. http://www.bidii.co.uk/pdfs/ArticleD4_MelaninInTheBody.pdf
  3. http://health-equity.pitt.edu/568/1/Yerger,_Malone_-_Melanin_Article.pdf
  4. http://am.ascb.org/files/Bioeducate/FawcettTheCellChapter11.pdf
  5. http://journal.scconline.org/pdf/cc1968/cc019n09/p00565-p00580.pdf
  6. http://www.sciencedirect.com/science/article/pii/S1357272597000137

[Leitura Adicional: Melanina]

Last Updated: Sep 8, 2014

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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.
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