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Nucleoside
Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotide is composed of a nucleobase, a five-carbon sugar, and one or more phosphate groups. In a nucleoside, the anomeric carbon is linked through a glycosidic bond to the N9 of a purine or the N1 of a pyrimidine. Nucleotides are the molecular building blocks of DNA and RNA. List of nucleosides and corresponding nucleobases ''This list does not include modified nucleobases and the corresponding nucleosides'' Each chemical has a short symbol, useful when the chemical family is clear from the context, and a longer symbol, if further disambiguation is needed. For example, long nucleobase sequences in genomes are usually described by CATG symbols, not Cyt-Ade-Thy-Gua (see '' Nucleic acid sequence § Notation''). Sources Nucleosides can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleobase
Nucleotide bases (also nucleobases, nitrogenous bases) are nitrogen-containing biological compounds that form nucleosides, which, in turn, are components of nucleotides, with all of these monomers constituting the basic building blocks of nucleic acids. The ability of nucleobases to form base pairs and to stack one upon another leads directly to long-chain helical structures such as ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). Five nucleobases— adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U)—are called ''primary'' or ''canonical''. They function as the fundamental units of the genetic code, with the bases A, G, C, and T being found in DNA while A, G, C, and U are found in RNA. Thymine and uracil are distinguished by merely the presence or absence of a methyl group on the fifth carbon (C5) of these heterocyclic six-membered rings. In addition, some viruses have aminoadenine (Z) instead of adenine. It differs in having an extra amine group, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosin
Adenosine (symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9-glycosidic bond. Adenosine is one of the four nucleoside building blocks of RNA (and its derivative deoxyadenosine is a building block of DNA), which are essential for all life on Earth. Its derivatives include the energy carriers adenosine mono-, di-, and triphosphate, also known as AMP/ADP/ATP. Cyclic adenosine monophosphate (cAMP) is pervasive in signal transduction. Adenosine is used as an intravenous medication for some cardiac arrhythmias. Adenosyl (abbreviated Ado or 5'-dAdo) is the chemical group formed by removal of the 5′-hydroxy (OH) group. It is found in adenosylcobalamin (an active form of vitamin B12) and as a radical in the radical SAM enzymes. Medical uses Supraventricular tachycardia In individuals with supraventricular tachycardia (SVT), adenosine is a first line treatment use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymidine
Thymidine (nucleoside#List of nucleosides and corresponding nucleobases, symbol dT or dThd), also known as deoxythymidine, deoxyribosylthymine, or thymine deoxyriboside, is a pyrimidine nucleoside, deoxynucleoside. Deoxythymidine is the DNA nucleoside T, which pairs with deoxyadenosine (A) in double-stranded DNA. In cell biology it is used to cell synchronization, synchronize the cells in G1/early S phase. The prefix deoxy- is often left out since there are no precursors of thymine nucleotides involved in RNA synthesis. Before the boom in thymidine use caused by the need for thymidine in the production of the antiretroviral drug Zidovudine, azidothymidine (AZT), much of the world's thymidine production came from herring sperm. Thymidine occurs almost exclusively in DNA but it also occurs in the T arm, T-loop of tRNA. Structure and properties In its composition, deoxythymidine is a nucleoside composed of deoxyribose (a pentose sugar) joined to the pyrimidine base thymine. De ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine
Adenosine (symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9- glycosidic bond. Adenosine is one of the four nucleoside building blocks of RNA (and its derivative deoxyadenosine is a building block of DNA), which are essential for all life on Earth. Its derivatives include the energy carriers adenosine mono-, di-, and triphosphate, also known as AMP/ADP/ATP. Cyclic adenosine monophosphate (cAMP) is pervasive in signal transduction. Adenosine is used as an intravenous medication for some cardiac arrhythmias. Adenosyl (abbreviated Ado or 5'-dAdo) is the chemical group formed by removal of the 5′-hydroxy (OH) group. It is found in adenosylcobalamin (an active form of vitamin B12) and as a radical in the radical SAM enzymes. Medical uses Supraventricular tachycardia In individuals with supraventricular tachycardia (SVT), adenosine is a first line trea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uracil
Uracil () (nucleoside#List of nucleosides and corresponding nucleobases, symbol U or Ura) is one of the four nucleotide bases in the nucleic acid RNA. The others are adenine (A), cytosine (C), and guanine (G). In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced by thymine (T). Uracil is a demethylated form of thymine. Uracil is a common and naturally occurring pyrimidine derivative. The name "uracil" was coined in 1885 by the German chemist Robert Behrend, who was attempting to synthesize derivatives of uric acid. Originally discovered in 1900 by Alberto Ascoli, it was isolated by hydrolysis of yeast nuclein; it was also found in bovine thymus and spleen, herring sperm, and wheat Cereal germ, germ. It is a planar, unsaturated compound that has the ability to absorb light. Uracil that was formed extraterrestrially has been detected in the Murchison meteorite, in near-Earth asteroid 162173 Ryugu, Ryugu, and possibly on the surface of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleotide
Nucleotides are Organic compound, organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all Life, life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common Nutrient, nutrients by the liver. Nucleotides are composed of three subunit molecules: a nucleobase, a pentose, five-carbon sugar (ribose or deoxyribose), and a phosphate group consisting of one to three phosphates. The four nucleobases in DNA are guanine, adenine, cytosine, and thymine; in RNA, uracil is used in place of thymine. Nucleotides also play a central role in metabolism at a fundamental, cellular level. They provide chemical energy—in the form of the nucleoside triphosphates, adenosine triphosphate (ATP), guanosine triphosphate (GTP), cytidine triphosphate (CTP), and uridine triph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deoxyadenosine
Deoxyadenosine (symbol dA or dAdo) is a deoxyribonucleoside. It is a derivative of the nucleoside adenosine, differing from the latter by the replacement of a hydroxyl group (-OH) by hydrogen (-H) at the 2′ position of its ribose sugar moiety. Deoxyadenosine is the DNA nucleoside A, which pairs with deoxythymidine (T) in double-stranded DNA. In absence of adenosine deaminase (ADA) it accumulates in T lymphocytes and kills these cells resulting in a genetic disorder known as adenosine deaminase severe combined immunodeficiency disease ( ADA-SCID). See also *Deoxyribonucleotide A deoxyribonucleotide is a nucleotide that contains deoxyribose. They are the monomeric units of the informational biopolymer, deoxyribonucleic acid (DNA). Each deoxyribonucleotide comprises three parts: a deoxyribose sugar (monosaccharide), a ni ... * Cordycepin (3′-deoxyadenosine) * Severe combined immunodeficiency References Nucleosides Purines Hydroxymethyl compounds {{Cell-bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-Methyluridine
The chemical compound 5-methyluridine (symbol m5U or m5U), also called ribothymidine (rT), is a pyrimidine nucleoside. It is the ribonucleoside counterpart to the deoxyribonucleoside thymidine, which lacks a hydroxyl group at the 2' position. 5-Methyluridine contains a thymine base joined to a ribose pentose sugar. It is a white solid. m5U is one of the most common modifications made to cellular RNA. It almost universally occurs in position 54 (part of the T arm) of eukaryotic and bacterial tRNA, serving to stabilize the molecule. The same "T-loop" motif occurs in many other forms of noncoding RNA such as tmRNA and rRNA Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal .... Loss of the tRNA modification does not usually produce a different, less fit, phenotype. See also * 5-Met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purine
Purine is a heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which include substituted purines and their tautomers. They are the most widely occurring nitrogen-containing heterocycles in nature. Dietary sources Purines are found in high concentration in meat and meat products, especially internal organs, such as liver and kidney, and in various seafoods, high-fructose beverages, alcohol, and yeast products. Examples of high-purine food sources include anchovies, sardines, liver, beef, kidneys, brains, monkfish, dried mackerel, and shrimp. Foods particularly rich in hypoxanthine, adenine, and guanine lead to higher blood levels of uric acid. Foods having more than 200 mg of hypoxanthine per 100 g, particularly animal and fish meats containing hypoxanthine as more than 50% of total purines, are more likely to increase uri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guanosine
Guanosine (symbol G or Guo) is a purine nucleoside comprising guanine attached to a ribose ( ribofuranose) ring via a β-N9- glycosidic bond. Guanosine can be phosphorylated to become guanosine monophosphate (GMP), cyclic guanosine monophosphate (cGMP), guanosine diphosphate (GDP), and guanosine triphosphate (GTP). These forms play important roles in various biochemical processes such as synthesis of nucleic acids and proteins, photosynthesis, muscle contraction, and intracellular signal transduction (cGMP). When guanine is attached by its N9 nitrogen to the C1 carbon of a deoxyribose ring it is known as deoxyguanosine. Physical and chemical properties Guanosine is a white, crystalline powder with no odor and mild saline taste. It is very soluble in acetic acid, slightly soluble in water, insoluble in ethanol, diethyl ether, benzene and chloroform. Functions Guanosine is required for an RNA splicing reaction in mRNA, when a "self-splicing" intron removes itself from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
