You might have guessed already that melanin is one of the pigments that causes the colour of your hair, skin and eyes. But did you know that there are several types of melanin?
That’s right, the pigment we thought we knew so well is actually a family of pigments. Melanin is produced by melanocytes and is formed by aggregating several different component molecules together. The variability in the combinations of molecules results in the different types of melanin. The exact composition and structures of these melanin molecules are still being researched. But it is known that the metabolism of an amino acid, tyrosine, is required to produce melanin.
Everyone seems to have a relatively similar concentration of melanocytes in their bodies; however, the frequency at which the melanocytes are induced to produce melanin varies with different ethnicities and individuals due to an increase or decrease in the expression of the melanin-producing genes.
Benefits to having a lot of melanin
This dark pigment allows for the absorption of UV radiation, which prevents our cells from dying or becoming cancerous. Melanin helps protect our DNA from being damaged by UV rays. This aspect is extremely important as DNA encodes almost all of the parts of our body, with the exception of the bacteria that exist inside and our mitochondria (which we inherit from our moms). If even a single mutation were introduced into our genome, there’s a chance that it will result in a malfunctioning protein which can lead to the breakdown of different biological processes.
For cold-blooded animals, melanin also provides a way to absorb heat from sunlight.
Disadvantages to producing a lot of melanin
Having too much melanin can mean that even the smallest of stimuli, like a scratch, can induce the production of more melanin. This results in the formation of dark patches of skin at those areas.
Two types of melanin molecules will be involved in next week’s post about Hair Colour, so stay tuned!
Simon, J.D. 2013. John D. Simon. Chem.virginia.edu. <http://chem.virginia.edu/faculty-research/faculty/john-d-simon/>. August 22, 2013.
Taylor, S.C. 2003. The Advantages and Disadvantages of Having More Melanin in Your Skin. About.com. <http://womenshealth.about.com/cs/dermatology/fr/brownskin_2.htm>. August 22, 2013.