Information AboutNucleic Acid |
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A nucleic acid is a Macromolecule made from Nucleotide chains. In Biochemistry these molecules can convey Genetic Information or form structures within Cells . The most common nucleic acids are ''' Deoxyribonucleic Acid ''' (DNA) and ''' Ribonucleic Acid ''' (RNA). Nucleic acids are universal in living things as they are found in all cells and Virus es. Artificial nucleic acids include Peptide Nucleic Acid (PNA), ''' Morpholino ''' and ''' Locked Nucleic Acid ''' (LNA), as well as ''' Glycol Nucleic Acid ''' (GNA) and ''' Threose Nucleic Acid ''' (TNA). Each of these is distinguished from naturally-occurring DNA or RNA by changes to the backbone of the molecule. CHEMICAL STRUCTURE The term "nucleic acid" is the generic name of a family of , Cytosine , and Guanine are in both RNA and DNA, while Thymine only occurs in DNA and Uracil only occurs in RNA. Other rare nucleic acid bases can occur, for example Inosine in strands of mature Transfer RNA . Nucleic acids are usually either single-stranded or double-stranded, though structures with three or more strands can form. A double-stranded nucleic acid consists of two single-stranded nucleic acids hydrogen- Bonded together, such as in the DNA double helix. In contrast, RNA is usually single-stranded, but any given strand may fold back upon itself to form double-helical regions. Within cells, DNA is usually double-stranded, though some Virus es have single-stranded DNA as their genome. The sugars and phosphates in nucleic acids are connected to each other in an alternating chain, linked by shared oxygens, forming a Phosphodiester functional group. In Conventional Nomenclature , the carbons to which the phosphate groups are attached are the 3' and the 5' carbons of the sugar. The bases extend from a glycosidic linkage to the 1' carbon of the pentose sugar ring. TYPES OF NUCLEIC ACIDS Nucleobases Main article: Nucleobase Nucleobases are Heterocyclic Aromatic Organic Compound s containing Nitrogen atoms. Nucleobases are the parts of RNA and DNA involved in Base Pair ing. Cytosine , Guanine , Adenine , Thymine are the found predominantly in DNA, while in RNA Uracil replaces Thymine . These are abbreviated as C, G, A, T, U, respectively. Two main classes exist, named for the molecule which forms their skeleton. These are the double-ringed Purine s and single-ringed Pyrimidine s. Adenine and guanine are purines (abbreviated as R), while cytosine, thymine, and uracil are all pyrimidines (abbreviated as Y). Hypoxanthine and Xanthine are mutant forms of adenine and guanine, respectively, created through Mutagen presence, through deamination (replacement of the amine-group with a hydroxyl-group). These are abbreviated HX and X. Nucleosides Main article: Nucleoside Nucleosides are Glycosylamine s made by attaching a Nucleobase (often referred to simply as bases) to a Ribose or Deoxyribose ( Sugar ) ring. In short, a nucleoside is a base linked to sugar. The names derive from the nucleobase names. The nucleosides commonly occurring in DNA and RNA include Cytidine , Uridine , Adenosine , Guanosine and Thymidine . When a phosphate is added to a nucleoside (by Phosphorylated by a specific Kinase enzyme), a nucleotide is produced. Nucleotides and deoxynucleotides Main article: Nucleotide A nucleotide consists of a nucleoside and one or more Phosphate Group s. Nucleotides are the Monomers of RNA and DNA , as well as forming the structural units of several important Cofactor s - CoA , Flavin Adenine Dinucleotide , Flavin Mononucleotide , Adenosine Triphosphate and Nicotinamide Adenine Dinucleotide Phosphate . In the Cell nucleotides play important roles in Metabolism , and signaling. Nucleotides are named after the nucleoside on which they are based, in conjunction with the number of phosphates they contain, for example:
Ribonucleic acids Main article: RNA Deoxyribonucleic acids Main article: DNA EXTERNAL LINKS
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