DNA deoxyribonucleic acid and RNA

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. 

The two major types of nucleic acids are DNA, deoxyribonucleic acid, and RNA,... 

Only two nucleic acids exist. They are DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). The structural complexity of nucleic acids falls far short of that of proteins. Like proteins, however, nucleic acids are polymers, with nucleotides being the monomer units. 

The nucleic acids DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are the molecules that play a fundamental role in the storage of genetic information, and the subsequent manipulation of this information. They are polymers whose building blocks are nucleotides, which are themselves combinations... 

Nucleic acids are biomolecules that pass genetic information from one generation to the next. Nucleic acids contained in DNA, deoxyribonucleic acid, and RNA, ribonucleic acid, are responsible for how all higher organism develop into unique species. DNA is present in the nucleus of all cells where segments of DNA comprise genes. DNA carries the information needed to produce RNA, which in turn produces protein molecules. A simplified view of the role of nucleic acids is to produce RNA, and the role of RNA is to produce proteins. 

Structural Genes. So far as known, structural genes in all organisms are composed of nucleic acids. In (he RNA viruses, the genes are RNA (ribonucleic acidl only, but in all other organisms, the DNA viruses and the cellular forms, which all possess both DNA (deoxyribonucleic acid) and RNA. the gene material is either known to be DNA, or assumed to be for good reason. 

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)... 

The biopolymers DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are present in any living cell and contain or transfer genetic information. They consist ofpurine (adenine, guanine) and pyrimidine bases (cytosine, uracil, thymine) linked to either 2-deoxy-D-ribose (DNA) or D-ribose (RNA). The sugar units are linked together via phosphates (Figure 23). 

All these compounds are more similar to benzene in stability and chemical behavior than they are to the alkenes. Many of these compounds are components of molecules that have significant effects on biological systems. For instance, the purines and pyrimidines are components of DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). DNA and RNA are the molecules responsible for storing and expressing the genetic information of an organism. The pyridine ring is found in... 

Nucleotides in DNA and RNA. Nucleotides are the monomeric units of the nucleic acids, DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). Each nucleotide consists of a heterocyclic nitrogenous base, a sugar, and phosphate DNA contains the purine bases adenine (A) and guanine (G) and the pyrimidine bases cytosine (C) and thymine (T). RNA contains A, G, and C, but it has uracil (U) instead of thymine. In DNA, the sugar is deoxyribose, whereas in RNA it is ribose. 

In the DNA polymer, the five-carbon sugar is deoxyribose (see Figure 21.12a) in the RNA polymer, it is ribose (see Figure 21.12b). This difference in the sugar moiecules present in the polymers is responsibie for the names DNA (deoxyribonucleic acid) and RNA (ribonucieic acid). 

Figure 1 is a reminder that a nucleic acid molecule consists of a backbone of ribose and phosphate, to which the various heterocyclic bases are attached. The sequence of these bases, of course, constitutes the genetic code. The primes are used in numbered positions of the ribose whereas the unprimed numbers refer to the numbering in the heterocyclic bases. The two diflFerent nucleic add molecules, DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), diflFer by the presence or absence of the 2 -hydroxyl groups. RNA contains the 2 -hydroxyl groups DNA does not. 

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. 

We ve now covered the last of the four major classes of biomolecules—the nucleic acids, DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). So much has been written and spoken about DNA in the media that our focus has been on the chemical details of DNA sequencing, synthesis, and metabolism rather than on simpler fundamentals. 

The formation of purines and pyrimidines which, in turn, are needed for the synthesis of the nucleic acids DNA (deoxyribonucleic acid), and RNA (ribonucleic acid), vital to all cell nuclei. This explains the important role of folacin in cell division and reproduction. 

Other studies pointed to the relationships between DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) and protein. In 1953, Francis Crick and James Watson described the structure of the DNA molecule, and gradually scientists have unraveled how cells manufacture specific proteins with specific amino acid sequences. 

Compounds that have one or more atoms other than carbon in the ring are heterocyclic. Hetero-cycUc compounds containing two or more nitrogen atoms are required for the transmission of genetic information. DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) contain substituted pyrimidine and purine rings. 

Two major types of nucleic acids are DNA (deoxyribonucleic acid), and RNA (ribonucleic acid). Both of them contain phosphate groups. These phosphate groups alternate with sugars to form the backbone of the molecule. The sugars are deoxyribose in the case of DNA and ribose in the case of RNA. Attached to each sugar is a purine or a pyrimidine base. The purine bases are adenine and guanine. One pyrimidine base is cytosine. In the case of RNA the other pyrimidine base is uracil, while for DNA the other pyrimidine base is thymine. 49. The complementary sequence to AGO is TCG. 

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