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The Science of Melanin, High school

Video of a squid gliding through the water of an aquarium

Squids squirt a cloud of dark ink when a predator comes close. Your hair gets its color from a pigment called melanin.

Could squid ink and your hair get their color from the same kind of pigment?

The Science of Melanin Magic

Melanin is a family of pigments that gives color to skin, hair and eyes. Dr. Raven Baxter explains three kinds of melanin and what each kind does. She also shows how squids, fungi and other living things use melanin.

Three hands with different skin tones pressed against a white wall
Melancholy, a word for deep sadness, comes from Greek melancholía, “condition of having black bile.”

Your word of the day is

MEL-uh-nin

melan-blackfrom Greek mélās
-inan ending for names of chemicalsfrom New Latin -ina

A family of natural pigments that give color to skin, hair, eyes, feathers and more.

A woman with bright red curly hair and freckles

Tyrosine is C9H11NO3, and cysteine is C3H7NO2S. On the way to pheomelanin, cysteine joins dopaquinone.

The sulfur atoms in pheomelanin come from the amino acid ____.

Drawing of the layers of human skin, with a close-up of the top layer showing squamous cells, basal cells and melanocytes

Small pieces of DNA that mimic UV damage made pigment cells produce about 7 times more melanin.

Which signal do the DNA experiments suggest tells melanocytes to make a tan?

Three smiling women with different skin tones standing close together indoors

Parkinson’s disease destroys neurons that hold neuromelanin, and mice and rats make no neuromelanin.

Why does the lack of neuromelanin in mice and rats make Parkinson’s disease harder to study in those animals?

Video of a squid swimming over a coral reef in clear blue water

Some squid release a blob of ink and mucus that looks like a squid.

How could a squid-shaped blob of dark ink help a squid escape a predator?

A school of reef squid swimming above a coral reef off American Samoa

Why does melanin’s dark color help a squid’s ink work?

A tall, colorful sculpture of a DNA double helix inside a science museum in Valencia, Spain

Claim, evidence, reasoning

People with albinism type OCA1A have changes in the tyrosinase gene, TYR, and make no melanin.

Which claim best explains how a change in the TYR gene can remove both eumelanin and pheomelanin?

A white lab mouse held in a gloved hand

Claim, evidence, reasoning

Which evidence best backs the claim that a TYR change stops both kinds of melanin?

A plastic molecule model next to pipettes and test tubes in a lab

Claim, evidence, reasoning

Which reasoning connects a TYR change to the loss of both eumelanin and pheomelanin?

NASA pictures of the sun taken in different kinds of light, from visible light to ultraviolet, each shown in its own color

Eumelanin turns more than 99.9% of the light energy it absorbs into heat. Melanin in skin absorbs about 50 to 75% of UV rays.

Is the claim that melanin blocks 99.9% of the UV rays hitting skin valid?

Video of bright sun rays streaming through a pine forest

What happens to most of the UV energy that eumelanin absorbs?

Four women seen from behind with different hair colors and textures

Eumelanin and pheomelanin share their first steps. A strong MC1R signal leads to eumelanin.

Which order of events determines whether a melanocyte makes eumelanin, pheomelanin or no melanin?

A crowd of many different people crossing a busy city street

Lesson complete

Today’s word

melanin

MEL-uh-nin

A family of natural pigments that give color to skin, hair, eyes, feathers and more.

Back to the lessonStart over
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Sources
  1. Shosuke Ito, Sandra Del Bino, Tomohisa Hirobe and Kazumasa Wakamatsu, at Fujita Health University, L’Oréal Research and Innovation and Shinjuku Skin Clinic, International Journal of Molecular Sciences, 2020
  2. Shosuke Ito and Kazumasa Wakamatsu, Fujita Health University, Journal of the European Academy of Dermatology and Venereology, 2011
  3. Michaela Brenner and Vincent Hearing, National Cancer Institute, Photochemistry and Photobiology, 2008
  4. Meredith and Riesz, University of Queensland, Photochemistry and Photobiology, 2004
  5. Erin Wolf Horrell, Mary Boulanger and John D’Orazio, University of Kentucky, Frontiers in Genetics, 2016
  6. Karen Grønskov, Jakob Ek and Karen Brondum-Nielsen, Kennedy Center, Denmark, Orphanet Journal of Rare Diseases, 2007
  7. Sandra Del Bino, Shosuke Ito, Juliette Sok and Kazumasa Wakamatsu, at L’Oréal Research and Innovation and Fujita Health University, Pigment Cell and Melanoma Research, 2022
  8. Commo, Gaillard and Bernard, L’Oréal Recherche, British Journal of Dermatology, 2004
  9. Luigi Zecca and colleagues, PNAS, 2004
  10. Svenja Esser, Maximilian Hausherr and colleagues, Ruhr University Bochum, Biomedicines, 2025
  11. Charles Derby, Georgia State University, Marine Drugs, 2014
  12. Radames Cordero and Arturo Casadevall, Johns Hopkins Bloomberg School of Public Health, Fungal Biology Reviews, 2017
  13. Agnieszka Zdybicka-Barabas, Sylwia Stączek, Magdalena Kunat-Budzyńska and colleagues, Maria Curie-Skłodowska University, International Journal of Molecular Sciences, 2025
  14. Vision and Change core concepts and competencies, as summarized in Brownell and others, CBE Life Sciences Education, 2014
  15. Word origins and formulas from Dictionary.com: melanin, melano-, -in, eumelanin, pheomelanin, neuromelanin, melanocyte, -cyte, eu-, neuro-, melancholy, melanoma, keratin, euphony, tyrosine, cysteine, pyrrole, thiazole
  16. The Metropolitan Museum of Art, “A Happy Occasion for Melencolia I”
  17. Spanish and French spellings from Wiktionary
  18. Transcript from the English captions uploaded with the YouTube video