Deoxyribonucleic acids secondary structure

Ribonucleic Acid. RNA yeast nucleic acid. Polynucleotide directly involved in protein synthesis found in both the nucleus and the cytoplasm oi cells. Description of components of RNA see Nucleic Acids. The Four primary nucleosides are adenosine, guanosine, cytidine and uridine minor nucleosides are also found. The nucleosides are linked by phosphate diester bonds from the 3 -hydroxyl of one D -ribose to the 5 -hydroxyl of the next. The secondary structure of RNA is that of an incompletely Organized single-stranded polynucleotide consisting of some areas with helical structure alternating with non helical lengths. Compere Deoxyribonucleic Acid (DNA). Structure Brown,... 

The basic monomers of nucleic acids are nucleotides which are made up of heterocyclic nitrogen-containing compounds, purines and pyrimidines, linked to pentose sugars. There are two types of nucleic acids and these can be distinguished on the basis of the sugar moiety of the molecule, Ribonucleic acids (RNA) contain ribose, while deoxyribonucleic acid (DNA) contains deoxyribose. The bases cytosine (C) adenine (A) and guanine (G) are common in both RNA and DNA. However, RNA molecules contain a unique base, uracil (U), while the unique DNA base is thymidine (T). These differences in the base structure markedly affect the secondary structures of these polymers. The structures of DNA and RNA are outlined in Appendix 5.2. 

How do DNA and RNA differ DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are the two kinds of nucleic acids. DNA contains the sugar deoxyribose, but RNA has ribose in the same position. The difference in the sugars gives rise to differences in their secondary and tertiary structures. The primary structure of nucleic acids is the order of bases in the polynucleotide sequence, and the secondary structure is the three-dimensional conformation of the backbone. The tertiary structure is specifically the supercoUing of the molecule. 

Deoxyribonucleic acid has been immobilized without chemical alteration by entrapment in agarose. The gel was either heated or dissolved in sodium perchlorate to destroy its secondary structure and then gelled in the presence of DNA by cooling or dialysis, respectively. Some rotational constraint of the DNA molecule was observed as evidenced by the binding constant obtained for the drug ethidium the nature of the constraint was discussed in terms of the known structure of agarose bihelices. 

Macroconformations consisting of two or three helices intertwined with each other are also sometimes called super helices or super secondary structures. An example is deoxyribonucleic acid, which forms a double helix from two complementary chains, each in the form of a helix (see Section 29). With synthetic polymers, both it-poly(methyl methacrylate) and poly(/ -hydroxybenzoic acid) appear to form double helices. Triple helices are, for example, formed by the protein, collagen (see Section 30). 

Marshall LE, Graham DR, Reich KA, Sigman DS. Cleavage of deoxyribonucleic acid by the l,10-phenanthrohne-cuprous complex. Hydrogen peroxide requirement and primary and secondary structure specificity. Biochemistry. 1981 20 244-250. 

Secondary Structure of Deoxyribonucleic Acid. Watson and Crick have developed a model on the basis of X-ray data obtained by Wilkins, which has been substantiated by other analyses. 

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