nucleotide

(redirected from cyclic n's)
Also found in: Dictionary, Thesaurus, Encyclopedia.

nucleotide

 [noo´kle-o-tīd]
any of a group of compounds obtained by hydrolysis of nucleic acids, consisting of a purine or pyrimidine base linked to a sugar (ribose or deoxyribose), which in turn is esterified with phosphoric acid.
cyclic n's those in which the phosphate group bonds to two atoms of the sugar forming a ring, as in cyclic AMP and cyclic GMP, which act as intracellular second messengers.

nu·cle·o·tide

(nū'klē-ō-tīd),
Originally a combination of a (nucleic acid) purine or pyrimidine, one sugar (usually ribose or deoxyribose), and a phosphoric group; by extension, any compound containing a heterocyclic compound bound to a phosphorylated sugar by an N-glycosyl link (for example, adenosine monophosphate, NAD+). For individual nucleotides see specific names.
Synonym(s): mononucleotide

nucleotide

(no͞o′klē-ə-tīd′, nyo͞o′-)
n.
Any of a group of compounds consisting of a nucleoside combined with a phosphate group and constituting the units that make up DNA and RNA molecules.

nu·cle·o·tide

(nū'klē-ō-tīd)
A combination of a (nucleic acid) purine or pyrimidine, one sugar (usually ribose or deoxyribose), and a phosphoric group.
Synonym(s): mononucleotide.

nucleotide

A molecule formed from the bonding of a purine or a pyrimidine base with a sugar and a mono-, di- or tri-phosphate group. Compare NUCLEOSIDE. Four different nucleotides may polymerize to form DNA. They are 2'-deoxyadenosine 5'-triphosphate; 2'-deoxyguanosine 5'-triphosphate; 2'-deoxycytidine 5'-triphosphate; and 2'-deoxythymidine 5'-triphosphate. These lengthy names are commonly abbreviated to dATP, dGTP, dCTP and dTTP. Even this is too clumsy when printing out the sequence of nucleotides in a length of DNA. In that case they are abbreviated to A, G, C and T (for adenine, guanine, cytosine and thymine). In RNA the sugar is not 2'-deoxyribose, but ribose itself. Also one of the RNA bases differs from that in DNA. Thymine is replaced by uracil. So the nucleotides of RNA are adenosine 5'-triphosphate; guanosine 5'-triphosphate; cytidine 5'-triphosphate; and uridine 5'-triphosphate. These are abbreviated to ATP, GTP, CTP and UTP or simply A, G, C and U.
Nucleotideclick for a larger image
Fig. 232 Nucleotide . Basic units of (a) deoxyribose sugar, (b) phosphate. Each carbon atom is numbered (1 prime, 2 prime, etc).
Nucleotideclick for a larger image
Fig. 233 Nucleotide . Linkage of the three nucleotide elements.

nucleotide

a complex organic molecule forming the basic unit of NUCLEIC ACIDS, with a structure made up of three components: a pentose sugar (ribose, or deoxyribose with one less oxygen atom), an organic base (PURINE type: ADENINE and GUANINE; or PYRIMIDINE type: CYTOSINE, THYMINE and URACIL) and a phosphate group (see Fig. 232 ). The three elements are linked together by two condensation reactions between the 1 sugar carbon and a base forming a NUCLEOSIDE, and the 5' sugar carbon and the phosphate (see Fig. 233 ). The nucleotides are formed into POLYNUCLEOTIDE CHAINS.

Nucleotide

Any of a group of organic molecules that link together to form the building blocks of DNA or RNA.
Mentioned in: Myotonic Dystrophy