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.
The hereditary molecule that controls cellular function is DNA (deoxyribonucleic acid). DNA contains information for protein synthesis in cells. The characteristics of organisms depend on the chemical reactions that occur inside them. These reactions are catalyzed by enzymes, which are highly specific proteins.