[too rz duh fawrs, -fohrs; French toor duh fawrs] /ËtÊÉrz dÉ ËfÉrs, -ËfoÊrs; French tur dÉ ËfÉrs/ (Show IPA) 1. an exceptional achievement by an artist, author, or the like, that is unlikely to be equaled by that person or anyone else; stroke of genius: Herman Melville's Moby Dick was a tour de force. 2. a particularly adroit maneuver or technique in handling a difficult situation:
edit Nucleobases. Purines make up two of the four nucleobases in DNA and RNA: adenine and guanine. Pyramidines make up the other bases in DNA and RNA: cytosine, thymine (in DNA) and uracil (in RNA).
A purine base that is a constituent of DNA and RNA and an important energy transport and storage component in cellular metabolism. adenine. A purine base that is a component of DNA and RNA, forming a base pair with thymine in DNA and with uracil in RNA. Adenine is also part of other biologically important compounds, such as ATP, NAD, and vitamin B-12, and occurs in tea. Many English speakers likely know this word.