nucleotide(redirected from Thionucleotides)
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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.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
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.
Farlex Partner Medical Dictionary © Farlex 2012
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.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
A combination of a (nucleic acid) purine or pyrimidine, one sugar (usually ribose or deoxyribose), and a phosphoric group.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
nucleotideA 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.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
nucleotidea 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.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
Any of a group of organic molecules that link together to form the building blocks of DNA or RNA.
Mentioned in: Myotonic Dystrophy
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.