ribose

noun

ri·​bose ˈrī-ˌbōs How to pronounce ribose (audio)
-ˌbōz
: a pentose C5H10O5 found especially in the dextrorotatory form as a component of many nucleosides (such as adenosine and guanosine) especially in RNA

Examples of ribose in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Other names commonly used for ribose include ribose sugar and simply ribose. — Lauren Manaker Ms, Rdn, Health, 19 July 2024 For example, all living things only use the right-handed form of the sugar ribose to form the backbone of DNA, giving it that the signature twist. — Nathaniel Scharping, Discover Magazine, 14 June 2016 For life on Earth, the sugars deoxyribose – which the researchers did not detect – and ribose are key building blocks of DNA and RNA, respectively. — Eric Lagatta, USA Today, 4 Dec. 2025 The study’s findings also indicate that the sugar ribose, which is one of the building blocks for RNA, may have been more widespread in the early solar system than deoxyribose, a building block of DNA. — Toria Sheffield, PEOPLE, 6 Dec. 2025 Analyzing pristine fragments of the asteroid delivered to Earth by NASA's OSIRIS-REx spacecraft in 2023, a team led by Yoshihiro Furukawa of Tohoku University in Japan found ribose, a crucial building block of RNA, and glucose, an energy-rich sugar used by nearly all life on Earth. — Sharmila Kuthunur, Space.com, 3 Dec. 2025

Word History

Etymology

International Scientific Vocabulary, from ribonic acid an acid C5H10O6 obtained by oxidation of ribose

First Known Use

1892, in the meaning defined above

Time Traveler
The first known use of ribose was in 1892

Rhymes for ribose

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Browse Nearby Words

ribonucleotide
ribose
riboso
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Cite this Entry

“Ribose.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ribose. Accessed 7 Jul. 2026.

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Kids Definition

ribose

noun
ri·​bose ˈrī-ˌbōs How to pronounce ribose (audio)
: a sugar that has five carbon atoms and five oxygen atoms in each molecule and is part of RNA compare deoxyribose

Medical Definition

ribose

noun
ri·​bose ˈrī-ˌbōs, -ˌbōz How to pronounce ribose (audio)
: a pentose C5H10O5 found especially in the levorotatory D-form as a constituent of a number of nucleosides (as adenosine, cytidine, and guanosine) especially in RNA

More from Merriam-Webster on ribose

Britannica.com: Encyclopedia article about ribose

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