DEFINITION of 'Commercial'. Relating to commerce. In the investment field, the term commercial is generally used to refer to a trading entity engaged in business activities that are hedged by positions in the futures or options markets.
The melanocortin 1 receptor controls which type of melanin is produced by melanocytes. When the receptor is activated, it triggers a series of chemical reactions inside melanocytes that stimulate these cells to make eumelanin. If the receptor is not activated or is blocked, melanocytes make pheomelanin instead of eumelanin.
Melanin is the brown pigment that is secreted by melanocytes, a  type of cell in your skin. The type, combination of types, and  amount of melanin determine your skin color, â¦ both naturally and  with sun exposure.Freckles and moles are caused by high localized  concentrations of melanin, for example.he general function of melanin in our skin is to protect and secure skin and skin cells from harmful ultraviolet rays and rays coming from sun. It contains infinite cells kno â¦ wn as melanocytes which increase their production of melanin in response to sun exposure.