nucleotide

American  

[noo-klee-uh-tahyd, nyoo-] / ˈnu kli əˌtaɪd, ˈnyu- /

noun

Biochemistry.

1. any of a group of molecules that, when linked together, form the building blocks of DNA or RNA: composed of a phosphate group, the bases adenine, cytosine, guanine, and thymine, and a pentose sugar, in RNA the thymine base being replaced by uracil.

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nucleotide British  

/ ˈnjuːklɪəˌtaɪd /

noun

1. biochem a compound consisting of a nucleoside linked to phosphoric acid. Nucleic acids are made up of long chains (polynucleotides) of such compounds

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nucleotide Scientific  

/ no̅o̅′klē-ə-tīd′ /

1. Any of a group of organic compounds composed of a nucleoside linked to a phosphate group. Nucleotides are the basic building blocks of nucleic acids.

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Other Word Forms

• internucleotide adjective

Etymology

Origin of nucleotide

First recorded in 1905–10; alteration of nucleoside

Compare meaning

How does nucleotide compare to similar and commonly confused words? Explore the most common comparisons:

• nucleoside vs. nucleotide

Example Sentences

This enables the essential information defining an organism’s core features—represented in the nucleotide sequences of DNA—to be passed down to its offspring.

From The Wall Street Journal • Dec. 26, 2025

"The evolutionary relationship of genes can usually be detected when two genes retain similar nucleotide sequences or encoded amino acid sequences," Kawasaki said, referring to the materials comprising an organism's genetic code.

From Science Daily • Jan. 30, 2024

The researchers didn’t attempt to redesign the genome one nucleotide at a time.

From Science Magazine • Nov. 8, 2023

For example, exposure to water can cause a chemical reaction called deamination that changes the nucleotide cytosine such that it appears to be the nucleotide thymine upon analysis.

From Scientific American • Aug. 25, 2023

And yet it is that improbable event, a small beneficial mutation in a nucleotide a ten-millionth of a centimeter across, that makes evolution go.

From "Cosmos" by Carl Sagan