Linear chains of amino acids that singly or in multiples of two or more form into proteins. Chains of just two amino acids are called, chains of three are, and any more are polypeptides.inear chains of amino acids that singly or in multiples of two or more form into proteins. Chains of just two amino acids are called, chains of three are, and any more are polypeptides.
Vitiligo: A Common Cause of Loss of Skin Pigment. Melanin is the pigment that gives the skin its characteristic color. Vitiligo is caused by a loss of pigment in the skin, due to destruction of pigment-forming cells known as melanocytes. Although vitiligo affects all races equally, it is more noticeable in dark-skinned people. Vitiligo can cause cosmetic problems.
A Dr. Mehmet Oz, MD , Cardiology (Cardiovascular Disease), answered. The white patches caused by the skin condition vitiligo can spread to other locations or can stay in one area. The course is unpredictable and varies from person to person. Some people with vitiligo say that new patches form on skin that is under pressure or exposed to friction. This can happen from shaving or rubbing from jewelry or clothing.