Deoxyribonucleic acid cells

Nucleic acids are acidic substances present m the nuclei of cells and were known long before anyone suspected they were the primary substances involved m the storage transmission and processing of genetic information There are two kinds of nucleic acids ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) Both are complicated biopolymers based on three structural units a carbohydrate a phosphate ester linkage between carbohydrates and a heterocyclic aromatic compound The heterocyclic aro matic compounds are referred to as purine and pyrimidine bases We 11 begin with them and follow the structural thread... 

Section 28 7 Nucleic acids are polynucleotides present m cells The carbohydrate component is D nbose m ribonucleic acid (RNA) and 2 deoxy d ribose m deoxyribonucleic acid (DNA)... 

DNA (deoxyribonucleic acid) (Section 28 7) A polynucleotide of 2 deoxynbose present in the nuclei of cells that serves to store and replicate genetic information Genes are DNA... 

Proteins, ubiquitous to all living systems, are biopolymers (qv) built up of various combinations of 20 different naturally occurring amino acids (qv). The number of proteins in an organism may be as small as half a do2en, as in the case of the simple bacterial vims M13, or as large as 50,000, as in the human system. Proteins are encoded by the deoxyribonucleic acid (DNA) that is present in all living cells. 

Chemotherapeutic agents are grouped by cytotoxic mechanism. The alkylating agents, such as cyclophosphamide [50-18-0] and melphalan [148-82-3] interfere with normal cellular activity by alkylation deoxyribonucleic acid (DNA). Antimetabohtes, interfering with complex metaboHc pathways in the cell, include methotrexate [59-05-2] 5-fluorouracil [51-21-8] and cytosine arabinoside hydrochloride [69-74-9]. Antibiotics such as bleomycin [11056-06-7] and doxombicin [23214-92-8] h.a.ve been used, as have the plant alkaloids vincristine [57-22-7] and vinblastine [865-21-4]. 

Fohc acid is a precursor of several important enzyme cofactors required for the synthesis of nucleic acids (qv) and the metaboHsm of certain amino acids. Fohc acid deficiency results in an inabiUty to produce deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and certain proteins (qv). Megaloblastic anemia is a common symptom of folate deficiency owing to rapid red blood cell turnover and the high metaboHc requirement of hematopoietic tissue. One of the clinical signs of acute folate deficiency includes a red and painhil tongue. Vitamin B 2 folate share a common metaboHc pathway, the methionine synthase reaction. Therefore a differential diagnosis is required to measure foHc acid deficiency because both foHc acid and vitamin B 2 deficiency cause... 

Vimses are one of the smallest biological entities (except viroids and prions) that carry all the iaformation necessary for thek own reproduction. They are unique, differing from procaryotes and eucaryotes ia that they carry only one type of nucleic acid as genetic material, which can be transported by the vims from one cell to another. Vimses are composed of a shell of proteki enclosing a core of nucleic acid, either ribonucleic acid (RNA) or deoxyribonucleic acid (DNA), that codes for vkal reproduction. The outer shell serves as a protective coat to keep the nucleic acid kitact and safe from enzymatic destmction. In addition to thek proteki coat, some vimses contain an outer covering known as an outer envelope. This outer envelope consists of a Hpid or polysaccharide material. 

Deoxyribonuclease (DNAase), an enzyme that degrades deoxyribonucleic acid, has been used in patients with chronic bronchitis, and found to produce favorable responses presumably by degrading the DNA, contributed by cell nuclei, to inflammatory mucus (213). Lysozyme [9001 -63-2] hydrolyzes the mucopeptides of bacterial cell walls. Accordingly, it has been used as an antibacterial agent, usually in combination with standard antibiotics. Topical apphcations are also useful in the debridement of serious bums, cellulitis, and dermal ulceration. 

The nucleic acids, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), are the chemical carriers of a cell s genetic information. Coded in a cell s DNA is the information that determines the nature of the cell, controls the cell s growth and division, and directs biosynthesis of the enzymes and other proteins required for cellular functions. 

Deoxyribonucleic acid (DNA) (Section 28.1) The biopolymer consisting of deoxyribonucleotide units linked together through phosphate-sugar bonds. Found in the nucleus of cells, DNA contains an organism s genetic information. 

Within every living cell, there is an organic natural polymer called deoxyribonucleic acid or, more commonly, DNA. The DNA molecule is enormous its molar mass is estimated to be of the order of 2 x 1010 g. The molecule takes the form of a narrow, tightly coiled band, which, if straightened out, would have a length of about 1 m. 

Bogenhagen D and Clayton DA (1974) The number of mitochondrial deoxyribonucleic acid genomes in mouse I and human hela cells. J Biol Chem 249 7991-7995. 

The nucleus contains bundles of a fibrous material known as chromatin, which is made up of mixed proteins and deoxyribonucleic acid (DNA), the substance that carries the genetic information of the living organism of which the cell is a component. All cells replicate by division. When a cell replicates, DNA in the chromatin of the nucleus passes the genetic information from one generation to the next one. As the cell divides, the chromatin clusters into rodlike structures known as chromo-... 

Without recounting the research studies dealing with or formaldehyde under the influence of ultraviolet and gamma rays. These sugars are, as will be detailed later, parts of the most important and absolutely essential materials, ribonucleic and deoxyribonucleic acids (RNA and DNA, respectively), of all living cells and also of viruses. Certain purines and pyrimidines, other essential parts of DNA and RNA, are also reported to have appeared under experimental... 

A detailed discussion of the modes of occurrence and biological importance of the polynucleotides is outside the scope of this article. However, in examining the structures of polynucleotides, it is necessary to take into consideration the origins of the materials studied. The pioneer researches of Caspersson114 indicated that deoxyribonucleic acids are present exclusively in the nucleus, whereas ribonucleic acids are found chiefly in the cytoplasm and only to a small extent in the nucleus. This general outline of the distribution of nucleic acids within the cell has been confirmed and extended by more recent work,116 and it has been possible to isolate both types of nucleic acid from different cellular fractions of the same tissue.116... 

DNA Deoxyribonucleic acid - the information-bearing molecule in most (but not all) cells. 

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