Deoxyribose, in DNA

The nucleic acids DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are biological polymers that act as chemical carriers of an organism s genetic information. Enzyme-catalyzed hydrolysis of nucleic acids yields nucleotides, the monomer units from which RNA and DNA are constructed. Further enzyme-catalyzed hydrolysis of the nucleotides yields nucleosides plus phosphate. Nucleosides, in turn, consist of a purine or pyrimidine base linked to Cl of an aldopentose sugar—ribose in RNA and 2-deoxyribose in DNA. The nucleotides are joined by phosphate links between the 5 phosphate of one nucleotide and the 3 hydroxyl on the sugar of another nucleotide. 

Nucleotide A subunit of DNA or RNA consisting of a purine (adenine and guanine) or a pyrimidine base [thymine (DNA only), uracil (RNA only) and cytosine], a phosphate molecule, and a sugar molecule (deoxyribose in DNA and ribose in RNA). 

The structural components of nucleic acids. Nucleic acids are long linear polymers of nucleotides, called polynucleotides, (a) The nucleotide consists of a five-carbon sugar (ribose in RNA or deoxyribose in DNA) covalently linked at the 5 carbon to a phosphate, and at the 1 carbon to a nitrogenous base. (b) Nucleotides are distinguished by the types of bases they contain. These are either of the two-ring purine type or of the one-ring pyrimidine type. 

Although RNA and DNA are similar in their overall properties, the presence of the 2 -hydroxyl group of ribose in RNA and its replacement by 2 -deoxyribose in DNA make a large contribution to the different... 

Like proteins, nucleic acids are polymers of a small number of building blocks, called nucleotides. A nucleotide itself has several parts. The first part is a carbohydrate, either ribose (in RNA) or deoxyribose (in DNA). To ribose is attached one of four bases, either adenine (A), cytidine (C), guanine (G), or uracil (U). If the carbohydrate is deoxyribose then U is replaced by a similar base called thymine (T) A, C, and G are also used with deoxyribose. Attached to a different part of the car-... 

A molecule whose geometrical structure is not identical to its mirror image possesses chirality. For example, enantiomers are mirror-image structures of a chiral molecule. Two mirror-image molecules are identified as l- and D-enantiomers. Amino acids and deoxyribose in DNA are chiral molecules. Asy mmetry in biochemistry requires the constant catalytic production of the preferred enantiomer in the reactions between enantiomers, a process known as racemization. In systems with appropriate chiral autocatalysis, instability may appear. Due to random fluctuations, the instability occurs accompanying the bifurcation of asymmetric states in which one enantiomer dominates. These states of broken symmetry can be observed in the following simple model reaction scheme with chiral autocatalysis (Kondepudi and Prigogine, 1999)... 

Nucleic acids, both DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), are linear polymers of four bases linked to a sugar-phosphate backbone as shown in Fig. 2.5a. The differences between DNA and RNA reside in the sugar moiety forming the backbone, and in one of the four bases whereas the sugar in RNA is ribose, it is deoxyribose in DNA both molecules contain bases adenine (A), guanine (G), and cytosine (C)... 

C. The sugars in the nucleotides of RNA are hexoses, while they are the pentose deoxyribose in DNA. 

A sugar, P D-ribose (in RNA) or P D-2 -deoxyribose (in DNA). This sugar is in the cyclic five-membered furanoside form. 

Nucleoside A nitrogenous base (purines such as adenine or guanine pyrimidines such as uracil, thymine, or cytosine) in an A-p-glycosidic linkage to a pentose sugar (deoxyribose in DNA and ribose in RNA). 

Recent studies have revealed novel facets of 4 -oxidahon of 2-deoxyribose in DNA. In all cases, one pathway leads to a 2 -deoxypentos-4-ulose abasic site (Figure 2.4). In addition, the other two pathways both entail formation of a strand break... 

Chen, B., Bohnert, T., Zhou, X., and Dedon, P.C. (2004) 5 -(2-Phosphoryl-l,4-dioxobutane) as a product of 5 -oxida-tion of deoxyribose in DNA elimination as trans-l,4-dioxo-2-butene and approaches to analysis. Chem. Res. Toxicol, 17, 1406-1413. 

DNA and RNA are polymers of nucleotides, which are composed of a five-carbon sugar (ribose in RNA and 2 -deoxyribose in DNA), a nitrogenous base, and one, two, or three phosphoryl groups. There are two kinds of nitroge-... 

The asymmetry of the nucleoside monophosphate monomers of nucleic acids gives the strand a "polarity". We describe the polarity relative to the numbering of the carbons in the sugar (ribose in RNA deoxyribose in DNA). For example, in Figure 4.1, the strand is said to be oriented 5 to 3 as it goes from top to bottom. 

RNA contains ribose, phosphate, adenine, guanine, cytosine, and uracil DNA has a very similar structure except that 2-deoxyribose replaces ribose and thymine replaces uracil Thus adenine, guanine, and cytosine are found in combination with either sugar, but uracil is associated only with ribose (in RNA) and thymine is associated only with 2-deoxyribose (in DNA). 

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