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Nucleobase (Molecule of the Month for January 2020)


Nucleobases, also known as nitrogenous bases or often simply bases, are nitrogen-containing biological compounds that form nucleosides, which, in turn, are components of nucleotides, with all of these monomers constituting the basic building blocks of nucleic acids. The ability of nucleobases to form base pairs and to stack one upon another leads directly to long-chain helical structures such as ribonucleic acid (RNA) and deoxyribonucleic acid (DNA).

Five nucleobases—adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U)—are called primary or canonical. They function as the fundamental units of the genetic code, with the bases A, G, C, and T being found in DNA while A, G, C, and U are found in RNA. Thymine and uracil are distinguished by merely the presence or absence of a methyl group on the fifth carbon (C5) of these heterocyclic six-membered rings

The 5' to 3' (read "5 prime to 3 prime") directions are: down the strand on the left, and up the strand on the right. The strands twist around each other to form a double helix structure.

Formal Chemical Name (IUPAC)



Picture of Nucleobase 3D model

click on the picture of  Nucleobase above to interact
with the 3D model of the
Nucleobase structure
(this will open a new browser window)

Picture of Nucleobase

Update by Karl Harrison
(Molecule of the Month for January 2020 )

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