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This nucleotide contains the five-carbon sugar deoxyribose (at center), a nucleobase called adenine (upper right), and one phosphate group (left). The deoxyribose sugar joined only to the nitrogenous base forms a Deoxyribonucleoside called deoxyadenosine, whereas the whole structure along with the phosphate group is a nucleotide, a constituent of DNA with the name deoxyadenosine monophosphate.
Cytosine, thymine, and uracil are pyrimidines, hence the glycosidic bonds form between their 1 nitrogen and the 1' -OH of the deoxyribose. For both the purine and pyrimidine bases, the phosphate group forms a bond with the deoxyribose sugar through an ester bond between one of its negatively charged oxygen groups and the 5' -OH of the sugar. [2]
Base pairing: Two base pairs are produced by four nucleotide monomers, nucleobases are in blue. Guanine (G) is paired with cytosine (C) via three hydrogen bonds, in red. Adenine (A) is paired with uracil (U) via two hydrogen bonds, in red. Purine nucleobases are fused-ring molecules. Pyrimidine nucleobases are simple ring molecules.
Nucleic acids are generally very large molecules. Indeed, DNA molecules are probably the largest individual molecules known. Well-studied biological nucleic acid molecules range in size from 21 nucleotides (small interfering RNA) to large chromosomes (human chromosome 1 is a single molecule that contains 247 million base pairs [18]).
The stability can be measured in various ways; a common way is the melting temperature (also called T m value), which is the temperature at which 50% of the double-strand molecules are converted to single-strand molecules; melting temperature is dependent on ionic strength and the concentration of DNA.
The primary structure of a biopolymer is the exact specification of its atomic composition and the chemical bonds connecting those atoms (including stereochemistry).For a typical unbranched, un-crosslinked biopolymer (such as a molecule of a typical intracellular protein, or of DNA or RNA), the primary structure is equivalent to specifying the sequence of its monomeric subunits, such as amino ...
The 3′-hydroxyl is necessary in the synthesis of new nucleic acid molecules as it is ligated (joined) to the 5′-phosphate of a separate nucleotide, allowing the formation of strands of linked nucleotides. Molecular biologists can use nucleotides that lack a 3′-hydroxyl (dideoxyribonucleotides) to interrupt the replication of DNA.
Although DNA consists of relatively rigid, very large elongated biopolymer molecules called fibers or chains (that are made of repeating nucleotide units of four basic types, attached to deoxyribose and phosphate groups), its molecular structure in vivo undergoes dynamic configuration changes that involve dynamically attached water molecules ...