What does guanine mean?
Guanine is a nitrogenous base that serves as one of the four fundamental building blocks of DNA and RNA. Together with adenine, cytosine, and thymine or uracil, it carries and transmits genetic information in biological molecules. In double-stranded DNA, guanine forms a complementary base pair with cytosine, while in RNA it can also pair with uracil. The letter G conventionally represents guanine in written DNA sequences. The word is principally used in biochemistry, genetics, medicine, and molecular biology, especially when describing genes, mutations, base pairs, nucleotides, and DNA composition. Guanine was historically isolated from guano, a nitrogen-rich fertilizer, which explains its unusual name. Its importance extends beyond genetics: variations in guanine and related molecular structures can influence cellular processes, and abnormal DNA patterns involving guanine may be associated with disease. Understanding this term helps clarify how genetic information is organized and copied.
nounA purine base and one of the four nucleotide bases found in DNA and RNA. In double-stranded DNA, guanine pairs with cytosine; in RNA, it can pair with cytosine or uracil.
- A nitrogenous purine base occurring in DNA and RNA, where it carries genetic information and participates in base pairing.
"The mutation replaced adenine with guanine, altering the gene's amino-acid sequence."
"The laboratory identified a guanine-to-adenine mutation in the tumor sample."
"A hairpin structure formed when the RNA strand folded brought two guanine bases together."
The plural is standard but relatively uncommon, and is most natural when individual base molecules or occurrences are being counted.
"The two guanines in the folded RNA were paired with cytosines elsewhere in the strand."
One of life's four molecular letters, guanine is the G in the familiar DNA alphabet A-T-C-G.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does guanine come from?
The English word was borrowed from French guanine, ultimately from Spanish guano, the nitrogen-rich fertilizer from which the substance was first isolated. The name therefore links the chemical base to its original biological source. Related biochemical terms, including guanosine, guanidine, and guanylate, were subsequently formed on the same guanine or guano stem.
How guanine is actually used
The term is specialized and formal, used chiefly in biochemistry, genetics, and molecular biology. It normally refers to the base rather than to a nucleotide containing it.
Easily confused with guanine
Guanine is a purine base used as a building block in DNA and RNA, whereas guanidine is a different nitrogen-rich chemical compound.