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.
In humans, the pineal gland controls our biorhythms and works in conjunction with the hypothalamus gland to control our thirst, hunger, sexual desire and biological clock that is associated with the aging process.he high melatonin levels in children are believed to inhibit their sexual development until melatonin levels decrease when puberty begins. Melatonin is created when the amino acid tryptophan is converted into the neurotransmitter serotonin, which is in turn synthesized into melatonin.