BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Melatonin. Circulating melatonin is produced in the pineal gland, under tight control by the central circadian pacemaker in the suprachiasmatic nucleus (SCN) region within the hypothalamus.

Detailed explanation-2: -Melatonin plays several key roles, and can be considered the central “relayer” which conveys information about light–dark cycles. In mammals, melatonin is also essential in the regulation of reproductive behaviour and sleep.

Detailed explanation-3: -Melatonin is secreted by the pineal gland, especially in response to darkness, and has been linked to the regulation of circadian rhythms.

Detailed explanation-4: -Melatonin is produced from serotonin (made from tryptophan), through a cascade of enzymatic reactions (Figure 1).

Detailed explanation-5: -Melatonin is an important hormone in circadian synchronization. This hormone is involved in many biological and physiological regulations in the body. It is an effective hormone for human biorhythm (circadian rhythm). The main role of this hormone is to maintain the biological clock and to adjust the body rhythm [25].