The Structure Of A Double Helix

950 WordsMay 23, 20164 Pages
The Deoxyribonucleic Acid (DNA) is a molecule that is able to encode hereditary information as well as transmitting such information from one generation to the next. The structure of the DNA is that of a double helix, much resembled as the structure similar to that of a spiral staircase. Such structural features arises from the strand of the DNA being a polymer consisting of a repeating polynucleotide chain of sugar group and phosphate backbone, with each sugar group being covalently bonded, by a hydrogen bond, to one of its complimenting four nitrogenous bases (nucleotides): cytosine (C) pairing with guanine (G), and adenine (A) pairing with thymine (T) (figure 2) [ ]. In the DNA a specific length of it is responsible for encoding and carrying out a specific function in the cell; however, each cell “specializes” itself by undergoing transcriptional genes silencing, regulating the gene activity in the cell as it requires, as in “turning off” such genes inherently. Gene silencing allows cells to be differentiated, wherein a skin cell during its development must have its nerve-specific genes turned off [ ]. On the molecular level, the DNA is remarkably long, if it were to be stretched end to end it would reach a length up to 6 feet, yet it is found in the minute sized organelles in the cells of organisms. Accordingly, despite its length, the DNA is wound around a spool-like proteins, called histones. Histones allow the DNA to be tightly wrapped enough to fit inside the
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