nucleotide

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Related to mononucleotide: Nicotinamide Mononucleotide

nucleotide

(no͞o`klēətīd', nyo͞o`–), organic substance that serves as a monomer in forming nucleic acidsnucleic acid,
any of a group of organic substances found in the chromosomes of living cells and viruses that play a central role in the storage and replication of hereditary information and in the expression of this information through protein synthesis.
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. Nucleotides consist of either a purinepurine,
type of organic base found in the nucleotides and nucleic acids of plant and animal tissue. The German chemist Emil Fischer did much of the basic work on purines and introduced the term into the chemical literature in the early 20th cent.
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 or a pyrimidinepyrimidine
, type of organic base found in certain coenzymes and in the nucleic acids of plant and animal tissue. The three major pyrimidines of almost universal distribution in living systems are cytosine, thymine, and uracil.
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 base, a riboseribose
, monosaccharide carbohydrate of universal distribution in living tissue, found in ribonucleic acid (RNA; see nucleic acid), free nucleotides, and various coenzymes.
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 or deoxyribose, and a phosphate group. Adenosine triphosphateadenosine triphosphate
(ATP) , organic compound composed of adenine, the sugar ribose, and three phosphate groups. ATP serves as the major energy source within the cell to drive a number of biological processes such as photosynthesis, muscle contraction, and the synthesis of
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 serves as the principle energy carrier for the cell's reactions. The most important nucleotides are those derived from the bases adenineadenine
, organic base of the purine family. Adenine combines with the sugar ribose to form adenosine, which in turn can be bonded with from one to three phosphoric acid units, yielding the three nucleotides adenosine monophosphate, adenosine diphosphate, and adenosine
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, guanineguanine
, organic base of the purine family. It was reported (1846) to be in the guano of birds; later (1879–84) it was established as one of the major constituents of nucleic acids.
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, cytosinecytosine
, organic base of the pyrimidine family. It was isolated from the nucleic acid of calf thymus tissue in 1894. A suggested structure for cytosine, published in 1903, was confirmed in the same year when that base was synthesized in the laboratory.
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, thyminethymine
, organic base of the pyrimidine family. Thymine was the first pyrimidine to be purified from a natural source, having been isolated from calf thymus and beef spleen in 1893–4.
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, and uraciluracil
, organic base of the pyrimidine family. It was isolated from herring sperm and also produced in a laboratory in 1900–1901. When combined with the sugar ribose in a glycosidic linkage, uracil forms a derivative called uridine (a nucleoside), which in turn can be
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.

Nucleotide

A cellular constituent that is one of the building blocks of ribonucleic acids (RNA) and deoxyribonucleic acid (DNA). In biological systems, nucleotides are linked by enzymes in order to make long, chainlike polynucleotides of defined sequence. The order or sequence of the nucleotide units along a polynucleotide chain plays an important role in the storage and transfer of genetic information. Many nucleotides also perform other important functions in biological systems. Some, such as adenosine triphosphate (ATP), serve as energy sources that are used to fuel important biological reactions. Others, such as nicotinamide adenine dinucleotide (NAD) and coenzyme A (CoA), are important cofactors that are needed to complete a variety of enzymatic reactions. Cyclic nucleotides such as cyclic adenosine monophosphate (cAMP) are often used to regulate complex metabolic systems. Chemically modified nucleotides such as fluoro-deoxyridine monophosphate (Fl-dUMP) contain special chemical groups that are useful for inactivating the normal function of important enzymes. These and other such compounds are widely used as drugs and therapeutic agents to treat cancer and a variety of other serious illnesses. See Coenzyme, Cyclic nucleotides, Nicotinamide adenine dinucleotide (NAD)

Nucleotides are generally classified as either ribonucleotides or deoxyribonucleotides. Both classes consist of a phosphorylated pentose sugar that is linked via an N-glycosidic bond to a purine or pyrimidine base. The combination of the pentose sugar and the purine or pyrimidine base without the phosphate moiety is called a nucleoside. See Purine, Pyrimidine

Ribonucleosides contain the sugar d -ribose, whereas deoxyribonucleosides contain the sugar 2-deoxyribose. The four most common ribonucleosides are adenosine, guanosine, cytidine, and uridine. The purine ribonucleosides, adenosine and guanosine, contain the nitrogenous bases adenine and guanine, respectively. The pyrimidine ribonucleosides, cytidine and uridine, contain the bases cytosine and uracil, respectively. Similarly, the most common deoxyribonucleosides include deoxyadenosine, deoxyguanosine, deoxycytidine, and thymidine, which contains the pyrimidine base thymine. Phosphorylation of the ribonucleosides or deoxyribonucleosides yields the corresponding ribonucleotide or deoxyribonucleotide. See Deoxyribonucleic acid (DNA), Enzyme, Nucleic acid, Ribonucleic acid (RNA)

nucleotide

[′nü·klē·ə‚tīd]
(biochemistry)
An ester of a nucleoside and phosphoric acid; the structural unit of a nucleic acid.
References in periodicals archive ?
Kometa, "On-line sample preparation for the determination of riboflavin and flavin mononucleotides in foodstuffs," Analyst, vol.
Both groups, for example, identified a natural riboswitch that recognizes flavin mononucleotide (FMN), a derivative of vitamin [B.
We have applied our instrument to the determination of riboflavin and flavin mononucleotide (FMN) in solution.
Riboflavin is the key component for two coenzymes, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), essential in the electron transport chain and final oxidation of macronutrients to energy.
Riboflavin is a yellow, fluorescent pigment that functions as a constituent of the coenzymes flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), which are present in virtually every animal cell.
We tested this with the recently synthesized RNA ribozymes, able to catalyze the synthesis of flavine adenine dinucleotide (FAD) from flavine mononucleotide (FMN).
The team used the BAT26 marker as an indicator of microsatellite instability, as the mononucleotide tract in BAT26 has been shown to be altered in nearly all mismatch-deficient tumors.
2]O), lecithin (from egg yolk), deferoxamine mesylate (DEF), flavin mononucleotide sodium salt (FMN), superoxide dismutase (SOD; from bovine erythrocytes, activity 3300 units/mg), catalase (CAT; from bovine liver, activity 10900 units/mg protein), and all other chemicals (of analytical grade or better) were purchased from Sigma, St.
It is known from co-crystal structures of the enzymes plus substrate that the mononucleotide binding fold is involved in the binding of ATP and the amino acid [6].
Nicotinamide mononucleotide, a key NAD(+) intermediate, treats the pathophysiology of diet- and age-induced diabetes in mice.
Secondary mutation in a coding mononucleotide tract in MSH6 causes loss of immunoexpression of MSH6 in colorectal carcinomas with MLH1/PMS2 deficiency.