Polynucleotide

A polynucleotide molecule is a biopolymer composed of 13 or more^[1] nucleotide monomers covalently bonded in a chain. DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are examples of polynucleotides with distinct biological function. The prefix poly comes from the ancient Greek πολυς (polys, many). DNA consists of two chains of polynucleotides, with each chain in the form of a helical spiral.

Sequence

Although DNA and RNA do not generally occur in the same polynucleotide, the four species of nucleotides may occur in any order in the chain. The sequence of DNA or RNA species for a given polynucleotide is the main factor determining its function in a living organism or a scientific experiment.

Polynucleotides in organisms

Polynucleotides occur naturally in all living organisms. The genome of an organism consists of complementary pairs of enormously long polynucleotides wound around each other in the form of a double helix. Polynucleotides have a variety of other roles in organisms.

Polynucleotides in scientific experiments

Polynucleotides are used in biochemical experiments such as polymerase chain reaction (PCR) or DNA sequencing. Polynucleotides are made artificially from oligonucleotides, smaller nucleotide chains with generally fewer than 30 subunits. A polymerase enzyme is used to extend the chain by adding nucleotides according to a pattern specified by the scientist.

References

↑ Polynucleotides at the US National Library of Medicine Medical Subject Headings (MeSH)

Nucleic acid constituents

Nucleobase

Nucleoside

Ribonucleoside	Adenosine Guanosine 5-Methyluridine Uridine 5-Methylcytidine Cytidine Inosine Xanthosine Wybutosine

Deoxyribonucleoside	Deoxyadenosine Deoxyguanosine Thymidine Deoxyuridine Deoxycytidine Deoxyinosine Deoxyxanthosine

Nucleotide
(Nucleoside monophosphate)

Ribonucleotide	AMP GMP m⁵UMP UMP CMP IMP XMP

Deoxyribonucleotide	dAMP dGMP dTMP dUMP dCMP dIMP dXMP

Cyclic nucleotide	cAMP cGMP c-di-GMP cADPR

Nucleoside diphosphate

ADP GDP m⁵UDP UDP CDP

dADP dGDP dTDP dUDP dCDP

Nucleoside triphosphate

ATP GTP m⁵UTP UTP CTP ITP XTP

dATP dGTP dTTP dUTP dCTP dITP dXTP

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