Deoxyribonucleic acid, or DNA, is a polymer of nucleotides linked together by specific bonds known as phosphodiester bridges. The phosphate group (PO3) of one nucleotide links to the hydroxyl group (OH) of the following nucleotide.Hundreds of millions of these linkages occur within the DNA polymer.he two DNA strands are held together by interchain hydrogen bonds. H-bonds pair the bases in one chain to the complementary bases in the other chain. (A/T and G/C).
The master circadian pacemaker in mammals is located in the suprachiasmatic nucleus in the rostroventral hypotha-lamus (Figure 2). Lesion studies identified it in 1972, and in vitro and in vivo functional studies, as well as transplant studies, have repeatedly corroborated the finding since then.
Circadian rhythms are, essentially, daily cycles of biological activity. They are based on a 24-hour period and influenced by the most regular variations in the environment like the alternation of night and day. Circadian rhythms can influence so many aspects of your wellbeing. Your sleep-wake cycles, hormone release, body temperature and other important bodily functions are all regulated by circadian rhythms. Abnormal circadian rhythms have been linked to various sleep disorders. They have also been associated with obesity, diabetes, depression, bipolar disorder and seasonal affective disorder. The importance of maintaining your circadian rhythms is well indicated.