Regions on the Earth's surface (or in its atmosphere) that are high above mean sea level are referred to as high altitude. High altitude is sometimes defined to begin at 2,400 metres (8,000 ft) above sea level. At high altitude, atmospheric pressure is lower than that at sea level.
In the trp (tryptophan) operon, the* repressor protein *binds to the product of the trp operon synthesis pathway, called *tryptophan *forming the active *corepresser *