Melanin-Skin,Hair and Eye colour

Breakthrough in melanin production

Prelims: General Science

Sep, 2015

• A group of scientists from Gulbarga University (not important) have made a major breakthrough in simplifying the production of the melanin.
• They cultured soluble melanin from a new micro organism “Tyrosinase (important)” from Actino bacterium (hard to remember; less important).

Melanin

All the bold words are important

• Melanin is a complex polymer.
• Derived from the amino acid tyrosine.
• Melanin is responsible for determining skin and hair colour.
• Present in the skin to varying degrees, depending on how much a population has been exposed to the sun historically (This is why people in tropical regions are usually dark).
• Melanin is an effective absorber of light; the pigment is able to dissipate (converts harmful ultraviolet into heat which dissipates through the neighbouring skin cells) over 99.9% of absorbed UV radiation.
• Because of this property, melanin is thought to protect skin cells from UVB radiation damage, reducing the risk of cancer.
• But Exposure to UV radiation is associated with increased risk of malignant melanoma, a cancer. (Dissipation of through melanin can cause DNA mutations in the neighbouring cells)
• Studies have shown a lower incidence for skin cancer in individuals with more concentrated melanin, i.e. darker skin tone.
• Melanin is used widely by pharmaceutical companies for treatment of melanoma, a type of skin cancer.
• And the cosmetics industry in the production of Skin Protection Factor (SPF) creams (that annoying Fair and Lovely Yami Gautam add).

Does fair and lovely really make you fair?

• Such creams create a thin film on skin that reflects or blocks sun’s radiation to certain extent.
• They help to retain moisture (less dryness and hence less cracks). Moisture is low in winter season.
• As they cannot affect Melanin, they cannot change the skin tone.
• If a cream alters melanin functioning, the person  will be more susceptible to skin cancer.

Eye colour

• Eye color happens because of the amount of the pigment melanin found in the eye. Not anywhere in the eye but in a very special place, the stroma of the iris.

1. Lots of melanin here gives brown eyes 
2. Less melanin gives green. 
3. Little or no melanin in the stroma of the iris gives blue eyes.

What about BLACK EYES?

• Brown eyes are commonly referred as black eyes (usually eyes are brown which appear to be black from a distance).

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