This means that it has a ribose as its sugar constituent with three phosphate groups attached. io free pronunciation tutorials. Purines are larger than pyrimidines because they have a two-ring structure while pyrimidines only have a single ring. Games. David. US English. Nucleotides can be further broken down to a. Understand the definition and structure of the compound uracil. Structure. Check 'uracil' translations into Croatian. It is a component of the combination drug tegafur/uracil. Discover if uracil is found in DNA. 2: DNA Replication. uracil noun grammar (chemistry) One of the bases of RNA. Adenine ___Cytosine ___Guanine ___Uracil ___Thymine ___ arrow_forward. Definition. Pyrimidines- Cytosine (C), Thymine (T; found only in DNA), Uracil (U; found only in RNA) Pentose sugar : There are two types of pentose sugars: Deoxyribose sugar (found only in DNA)Definition. See full answer below. 4K . DNA is the genetic material found in all living organisms, ranging from single-celled bacteria to multicellular mammals. In DNA, guanine is paired with cytosine. Understand the definition and structure of the compound uracil. . a base containing nitrogen that is found in RNA (but not in DNA) and derived from pyrimidine; pairs with adenine. It has a role as a Daphnia magna metabolite. Understand the definition and structure of the compound uracil. 1: (a) Ribonucleotides contain the pentose sugar ribose instead of the deoxyribose found in deoxyribonucleotides. Structure. Thermodynamic Potential for the Abiotic Synthesis of Adenine, Cytosine, Guanine, Thymine, Uracil, Ribose, and Deoxyribose in Hydrothermal Systems. The basic property derives from the lone electron pair on the nitrogen atom. These rules apply to both types of double-stranded nucleic acids, particularly, double-stranded DNA as well as double-stranded RNA (with an exception of A = T in. The correct answer is False. When base pairing with adenine, uracil acts as both a hydrogen bond acceptor and a hydrogen bond donor. B. Have we pronounced this wrong? Teach everybody how you say it using the comments below!!Looking for help to learn English? Claim top deals on the best Englis. Nov 14, 2023. During DNA replication, uracil will pair with adenine rather than guanine (as it would if the base was still cytosine), so an uncorrected cytosine-to. Noun [ edit] English Wikipedia has an article on: directionality (molecular biology) § 3′ end. Each strand has a backbone made of alternating sugar. Pyrimidines can be identified by their structure: six atoms in the shape of a ring. These abasic sites can be hydrolyzed by. It has adenine, thymine, Guanine and Cytosine, where adenine pairs up with thymine and guanine pairs up with cytosine, in case of RNA, thymine is replaced. This video shows you how to pronounce VascularIdentical copies of DNA reside in every single cell of an organism, from a lung cell to a muscle cell to a neuron. Here are 4 tips that should help you perfect your pronunciation of 'uracil':. Learn the function of uracil, as well as its properties. The process by which this occurs is called transcription. It is a thiocarbonyl compound and a nucleobase analogue. The molecule formed as a result of transcription: a) has uracil (U) instead of thymine (T) b) is identical in all ways (chemically, physically) to the DNA and thereby carries the code accurately. This is accomplished by the process of DNA replication. It is a part of both nucleosides and a nucleotide. Uracil: Uracil is one of the two nucleotide bases that can bond with adenine in a genomic molecule. Last updated. a. 3. 4K . Base-pairing Rules Definition. Samantha. The meaning of URACIL is a pyrimidine base C4H4N2O2 that is one of the four bases coding genetic information in the polynucleotide chain of RNA. U. noun uracil a pyrimidine present in all living cells, usually in a combined form, as in RNA. However, while RNA is transcribed using only these four bases, they are. Although this enzyme has evolved to remove uracil from. fluorouracil: [noun] a fluorine-containing pyrimidine base C4H3FN2O2 used as a neoplastic agent to treat some kinds of cancer. guanine. Uracil-N glycosylase deficiency is transmitted as an AR disease. It is a member of pyrimidines and a diazine. from . A nitrogenous base (also called nucleobase) is a nitrogen-containing compound that may form a nucleoside when they are attached to a five-carbon sugar ribose or deoxyribose. The bases combine with the sugar to make the nucleotides adenosine, guanosine, cytidine, thymidine, and uridine. Uracil: Definition & Structure. It under normal conditions is not seen in DNA but is present in RNA replacing thymine. Why is uracil used in RNA? Uracil is energetically less expensive for the production of thymine. Learn how to say/pronounce uracil in American English. DNA consists of the four nucleotide bases: adenine (A), guanine (G), cytosine (C) and thymine (T). Originally discovered in 1900, it was isolated by hydrolysis of yeast nuclein that was found in bovine thymus and spleen, herring sperm, and wheat germ. This can account for its utilization in RNA. How would you pronounce Uracil?What is uracil in English? Pronunciation, translation, synonyms, examples, rhymes, definitions of uracil in English. Its nucleoside contains a pyrimidine base, i. from . It codes genetic information for the transmission of inherited traits. Perfect your pronunciation and sound like a native speaker today!uracil - Translation to Spanish, pronunciation, and forum discussions. Nucleosides are components of. It should have Uracil replacing the Thymine as the base bonding with adenine in RNA. Biochemistry a pyrimidine base, C 4 H 4 N 2 O 2 , that is one of the fundamental components of RNA, in which it forms base pairs with. Cytosine base bonds with guanine via 3 hydrogen bonds in nuclei acids. 4K . Understand the definition and structure of the compound uracil. Uracil [edit | edit source]. uracil noun. 4K . premium features;. Look through examples of uracil translation in sentences, listen to pronunciation and learn grammar. Most methylated nucleotides are in the coding district of DNA minimal in the advertiser area. Fun Facts about the name Uracil. A Sugar — either ribose (in RNA. Our Apps are nice too! Dictionary. pyrimidine: [noun] a feeble organic base C4H4N2 of penetrating odor. In RNA, thymine is replaced with uracil. Transcription and translation are the two processes that convert a sequence of nucleotides from DNA into a sequence of amino acids to build the desired protein. In nucleic acids, it. Uridine (symbol U or Urd) is a glycosylated pyrimidine analog containing uracil attached to a ribose ring (or more specifically, a ribofuranose) via a β-N 1-glycosidic bond. Uracil (Lamivudine EP Impurity F) is a nitrogenous base on RNA nucleosides. Uracil is similar to thymine in terms of. Games. Hear the pronunciation of uracil . A. What is the scientific definition of uracil? Definition of uracil : a pyrimidine base C4H4N2O2 that is one of the four bases coding genetic information in the polynucleotide chain of RNA — compare adenine, cytosine, guanine, thymine. Thymine: Structure & Definition Quiz; Uracil: Definition & Structure Quiz; What is Deoxyribonucleic Acid? - Definition & Structure Quiz; Go to Nucleic Acids - DNA and RNA: Tutoring SolutionAdenine (not adenosine) 2. More than 50 mutations in the DPYD gene have been identified in people with dihydropyrimidine dehydrogenase deficiency. Uracil is a pyrimidine nucleobase with a chemical formula of C 4 H 4 N 2 O 2. Uridine is a nucleoside, whereas uracil is a standalone nucleobase. The analog is one of the five standard nucleosides which make up nucleic acids, the others being adenosine, thymidine, cytidine and guanosine. Related to this Question. A purine, on the other hand, has two rings of. Nucleic acids (NA) are key molecules that contain genetic information and participating in protein synthesis. from . English multilingual translator. uracil pronunciation. 00:00. Uracil glycosylase quickly cleaves the uracil residue from the DNA producing an apyrimidinic site. fluorouracil: [noun] a fluorine-containing pyrimidine base C4H3FN2O2 used as a neoplastic agent to treat some kinds of cancer. US English. This seems to be the case for the use of Adenine in ATP. 3. The response rate is improved by adding leucovorin [107 R]. Tags for the word Uracil: Hindi meaning of Uracil, What Uracil means in hindi, Uracil meaning in hindi, hindi mein Uracil. altruistic, Use the word bank to answer the question. ” In DNA, A and T pair. ura· cil ˈyu̇r-ə-ˌsilUracil like other pyrimidines is an aromatic heterocyclic compound with a pyrimidine ring that comprises alternating nitrogen and carbon atoms. 1 10. It is a component of the combination drug tegafur/uracil. It is readily deaminated into uracil through spontaneous reactions as it is unstable. The purines in DNA are adenine and guanine, the same as in RNA. Definition English: A uracil nucleotide containing a pyrophosphate group esterified to C5 of the sugar moiety. Thymine Definition. 2023-11-04. Guanine (G) is one of the four nucleotide bases in DNA, with the other three being adenine (A), cytosine (C) and thymine (T). In general, uracil occurs in RNA, not in DNA. Structurally, nucleic acid bases are substituted purines and pyrimidines. Understand the definition and structure of the compound uracil. Also called: 5-methyl uracil. DNA is the genetic material found in living organisms, all the way from single-celled bacteria to multicellular mammals like you and me. Interestingly, clear differences were shown between the uracil enrichment patterns induced by the two drugs. Tegafur is a chemotherapeutic prodrug of 5-fluorouracil (5-FU) used in the treatment of cancers. As for the nitrogenous base (or nucleobase) component, the common bases are adenine (A), guanine (G), cytosine (C), and uracil (U). The sequence of the four nucleotide bases encodes DNA’s information. It pairs with adenine and is symbolised by U. The nitrogen atoms are placed in the 1 and 3 positions around the ring. The others are adenine, guanine, and cytosine. Uracil and thymine have very similar structures; uracil is an unmethylated form of thymine. A ribonucleotide is a nucleotide that has a ribose as its sugar component. Yes, RNA always contains uracil as a base nucleotide that pairs with adenine in place of the thymine nucleotide. On degradation, uracil produces substrates such as carbon dioxide. Uridine monophosphate (UMP) is a nucleoside phosphate in being comprised of a ribonucleoside and one phosphate group. A uracil-based nucleotide is called uridine. Does adenine pair with uracil in. RNA is a single-stranded nucleotide chain containing the adenine (A), cytosine (C), uracil (U), and guanine (G) bases. A) Cytidine is deaminated to uracil so it would be difficult for any repair mechanism to differentiate between uracil that belongs in the sequence and uracil that resulted. Learn the function of uracil, as well as its properties. CYTOSINE, GUANINE, URACIL Pronunciation Symbols. One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has nitrogen atoms at positions 1 and 3 in the ring. With the formula C 5 H 5 N 5 O, guanine is a derivative of purine. DNA and RNA. 2. unselfish d. Its nucleoside contains a pyrimidine base, i. Uracil | Definition, Structure & Function. 5,6-Dihydrouracil acts as an intermediate in the catabolism of uracil. amino acids are bounded together into a polypeptide chain in a sequence specified by base triplets in messenger RNA; Transfer RNA delivers amino acids one at a time to ribosomes an RNA component of ribosomes catalyzes the chain-building reaction. altruistic, Use the word bank to answer the question. A virus that infects bacteria. noun. uracil noun. 1. They consist of a six-membered ring with two nitrogen atoms and four carbon atoms, but instead of being an aromatic ring with alternating double and single bonds they all have a ketone (carbonyl group) on the 2′ carbon atom (the carbon between the two. Sample translated sentence: RNA uses U (uracil) instead of T ↔ RNA bruker U (uracil) i stedet for T . As a nitrogenous base, cytosine is full of nitrogen atoms (it has three). Uracil is a pyrimidine base that is used in RNA in place of thymine. What does the word uracil mean? Find and lookup the definition, synonyms, and antonyms of the word uracil in our free online dictionary!The Learning Objective of this Module is to identify the different molecules that combine to form nucleotides. . The following products are also available:uracil - Meaning in English, what is the meaning of uracil in English dictionary, pronunciation, synonyms, usage examples and definitions of uracil in English and English. OneDefinition. Uracil is a demethylated form of thymine with the chemical formula C4H4N2O2. US. Found in RNA, it base pairs with adenine and replaces thymine during DNA transcription. Also see: uracil in Hindi. e. Nucleic acids, macromolecules made out of units called nucleotides, come in two naturally occurring varieties: deoxyribonucleic acid ( DNA) and ribonucleic acid ( RNA ). Nucleic acids. Pyrimidine, any of a class of organic compounds of the heterocyclic series characterized by a ring structure composed of four carbon atoms and two nitrogen atoms. Here are 4 tips that should help you perfect your pronunciation of 'uracil': Break 'uracil' down into sounds : [YOOR] + [UH] + [SIL] - say it out loud and exaggerate the sounds until you can consistently produce them. RNA is produced as needed in response to the dynamic cellular environment and the. Look through examples of uracil translation in sentences, listen to pronunciation and learn grammar. It has a chemical formula of C 4 H 5 N 3 O. The base can be a pyrimidine [ thymine (T), cytosine (C), and uracil (U)]; or a purine [ adenine (A) and. A nucleotide consists of a sugar molecule (either ribose in RNA or deoxyribose in DNA) attached to a phosphate group and a nitrogen-containing base. Uracil is a common and naturally occurring pyrimidine derivative. The nucleotide bases are made up of purines (adenine and. David. Adenine (not adenosine) 2. An RNA molecule has a backbone made of alternating phosphate groups and the sugar ribose, rather than the deoxyribose found in DNA. g. It has a role as a metabolite, a human metabolite, an Escherichia coli metabolite and a mouse metabolite. Thymine (T) is one of the four nucleotide bases in DNA, with the other three being adenine (A), cytosine (C) and guanine (G). DNA glycosylases—an ancient family of DNA repair proteins. Julia. In RNA, uracil binds to adenine via two hydrogen bonds. uracil attached to the ribose sugar. Pseudouridine (abbreviated by the Greek letter psi- Ψ) [1] is an isomer of the nucleoside uridine in which the uracil is attached via a carbon-carbon instead of a nitrogen-carbon glycosidic bond . W. . Quotes. uracil. Related to this Question. 4K . ID: GO:0046107 Synonyms: Articles referencing this term. A nucleotide is made up of three parts: a phosphate group, a 5-carbon sugar, and a nitrogenous base. Monoisotopic mass 112. US English. ( A) A nucleotide (guanosine triphosphate). Definición Español: Nucleótido de uracilo que contiene un grupo pirofosfato esterificado al C5 de la molécula de azúcar. Synonyms : U. When three continuous. uracil: ChEBI ID CHEBI:17568: Definition A common and naturally occurring pyrimidine nucleobase in which the pyrimidine ring is substituted with two oxo groups at positions 2 and 4. Base pairs refer to the sets of hydrogen-linked nucleobases that make up nucleic acids DNA and RNA. Examples of how to use “uracil” in a sentence from Cambridge Dictionary. enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule. In a nucleic acid chain, a subunit that consists of a sugar, a phosphate, and a nitrogenous base. RNA is generally single-stranded instead of double-stranded. uracil - Meaning in English, what is the meaning of uracil in English dictionary, pronunciation, synonyms, usage examples and definitions of uracil in English and English. Guanine, 1. A nucleoside is a nitrogenous base ( purine or pyrimidine) bound to a pentose sugar ribose or deoxyribose. Uracil (U): Uracil is a weak acid with the chemical compound C 4 H 4 N 2 O 2. Decoding biological principles using gene circuits. e. Definitions of uracil. Uracil is one of the nucleobases in the RNA, such as adenine, Guanine and cytosine where as in all living beings that contains DNA, lack uracil in its nucleotide base pairs. from . The carbon (C) and nitrogen (N) atoms are bonded by single and double bonds altering each other. : a pyrimidine base C4H4N2O2 that is one of the four bases coding genetic information in the polynucleotide chain of RNA compare adenine, cytosine, guanine, thymine. Uracil has a melting point of 335 °C. Ultraviolet light exposure causes a common DNA mutation where two adjacent thymine molecules form a. Which base will pair with uracil in RNA? Adenine. Having been provided to the early Earth as a component in such asteroidal materials, these molecules might have played a role. uracil - WordReference English dictionary, questions, discussion and forums. Thymine. . A portion of DNA whose sequence of nucleotides codes for a protein. A tablet formulation containing 5-ethynyluracil (GW776), an ethynyl derivative of uracil and the antineoplastic agent 5-Fluorouracil (5-FU) in a 10:1 ratio. Look through examples of Uracil translation in sentences, listen to pronunciation and learn grammar. cytosine: [noun] a pyrimidine base C4H5N3O that codes genetic information in the polynucleotide chain of DNA or RNA — compare adenine, guanine, thymine, uracil. Learn and practice the pronunciation of uracil. 2020 Dec 12;12(12):2969. uracile, U are the top translations of "uracil" into French. Uracil DNA-glycosylase (UNG) is a DNA repair enzyme that removes the highly mutagenic uracil lesion from DNA using a base flipping mechanism. Dotted lines show hydrogen bonds. It has a chemical formula of C 4 H 4 N 2 O 2. . Record ‘Uracil‘ in a full sentence then watch or listen back. Semiconservative replication refers to. Weird things about the name Uracil: The name spelled backwards is Licaru. Within a double-stranded DNA molecule, thymine bases on one strand pair with adenine bases on the opposite strand. Record yourself saying 'uracil' in full sentences, then watch yourself and listen. Video shows what uracil means. What is Uracil. The nitrogenous bases can be divided into two categories: purines and pyrimidines. Chapter 11 / Lesson 9. It has a role as an antithyroid drug and a metabolite. 08676 g/mol and a melting point of 335 °C. It also has one ring of carbon, which makes it a pyrimidine. You'll be able to mark your mistakes quite easily. The structure of uracil can be described as. noun. b. ura· cil ˈyu̇r-ə-ˌsil, -səl. a speech counterpart of orthographic u. Guanine-Cytosine base pair. haɪˈdrɒksɪl. Learn how to say Uracil with EmmaSaying free pronunciation tutorials. The four bases that make up DNA and RNA are adenine, cytosine. How to say Lyme all uracil in English? Pronunciation of Lyme all uracil with and more for Lyme all uracil. Here are 4 tips that should help you perfect your pronunciation of 'uracil': Break 'uracil' down into sounds : [YOOR] + [UH] + [SIL] - say it out loud and exaggerate the sounds until you can consistently produce them. Pyrimidine is the parent compound of the pyrimidines; a diazine having the two nitrogens at the 1- and 3-positions. coli CJ236 dut−ung −) at +37°C in 60 minutes. a single-stranded nucleic acid that encodes genetic information. In RNA, uracil pairs with adenine. Tags for the entry "uracil" What uracil means in Punjabi, uracil meaning in Punjabi, uracil definition, explanation, pronunciations and examples of uracil in Punjabi. They were first described by Dr. Location: It is located in the nucleus of a cell and in the mitochondria. Uracil-ftorafur is a combination of tegafur, an oral prodrug of fluorouracil, and uracil in a 1:4 molar ratio. Learn the function of uracil, as well as its properties. Zira. Sample translated sentence: Gumagamit ng U (“uracil”) ang RNA sa halip na T ↔ RNA uses U (uracil) instead of T . Properties [edit | edit source]. a base containing nitrogen that is found in RNA (but not in DNA) and derived from pyrimidine; pairs with adenine. It is also the synthesis of a single protein from a mRNA template. RNA though carries the genetic information of just one gene. . The four bases are incorporated into DNA as nucleotides. Definition and meaning can be found here:Definition. Definition. How to say acetylation in English? Pronunciation of acetylation with 2 audio pronunciations, 3 synonyms, 2 meanings, 14 translations, 1 sentence and more for acetylation. Like the UNG from E. RNA contains the nucleotides adenine, guanine, cytosine and uracil (U). from . RNA consists of ribose nucleotides (nitrogenous bases appended to a ribose sugar) attached by phosphodiester bonds, forming strands of varying lengths. Created by Sal Khan. Thus, adenine complementary base pairs with uracil in RNAs. Codon (image) Uracil (image) Anticodon (definition) group of three bases on a tRNA molecule that are complementary to an mRNA codon. Uracil is a pyrimidine base that is used in RNA in place of thymine. Definition. However, somatic mutation detection protocols use DNA from formalin-fixed and paraffin-embedded (FFPE) tumor tissues, which can result in detection of nonreproducible sequence artifacts, especially C:G > T:A transitions, in. Nucleic acids, macromolecules made out of units called nucleotides, come in two naturally occurring varieties: deoxyribonucleic acid ( DNA) and ribonucleic acid ( RNA ). Uracil has a molar mass of 112. It is generally accepted that negative discrimination against uracil in DNA is caused by the chemical instability of cytosine. Polymers (Basel) . Uridine is a nucleoside, whereas uracil is a standalone nucleobase. The nitrogenous base (guanine in this example) is linked to the 1′ carbon of the deoxyribose and the phosphate groups are linked to the 5′ carbon. What is single-stranded DNA-binding protein?Uracil may arise in DNA as a result of spontaneous cytosine deamination and/or misincorporation of dUMP during DNA replication. The guanine nucleoside is called guanosine . Is a polymer with a ribose and phosphate backbone with four varying bases: uracil, cytosine, adenine and guanine. The four different mutations observed in the three patients were located in the catalytic domain shared by both UNG isoforms (mitochondrial UNG1 and nuclear UNG2). Vad är Thymine - Definition, struktur, egenskaper 3. How to say Thymine in English? Pronunciation of Thymine with 3 audio pronunciations, 2 synonyms, 12 translations and more for Thymine. irritated c. Uracil is a pyrimidine base, which is an essential constituent of RNA. The present study will be an open-label, single-arm, single-center trial to develop a new. Check out the pronunciation, synonyms and grammar. All these transformations disrupt base pairing at the site of the change, and this produces a structural deformation in the double helix. Uracil definition, n. A nucleic acid is a biopolymer composed of monomeric units of nucleotides. DNA serves as the molecular basis of heredity through replication, expression, and translation processes. com member to unlock this answer! Create your account. Related to this Question. Understand the definition and structure of the compound uracil. uracil, a colourless, crystalline organic compound of the pyrimidine family that occurs as a component of ribonucleic acid ( RNA ), a molecule involved in the transmission of hereditary characteristics. S. uracil noun. 3. The word or phrase uracil refers to a base containing nitrogen that is found in RNA (but not in DNA) and derived from pyrimidine; pairs with adenine. helicase. Sample translated sentence: 5-(e)-bromovinyl uracil analogues and related pyrimidine nucleosides as anti-viral agents and methods of use ↔ Analogues uracile 5-(e)- bromovinyl et nucleosides pyrimidines associes ayant la fonction d'agents anti-viraux et procedes. Learn the function of uracil, as well as its properties. 1. It also has one ring of carbon, which makes it a pyrimidine. Each nucleotide that makes up a nucleic acid is comprised of phosphoric acid, sugar (5-carbon), and nucleobase. Uracil: Definition & Structure. Base + sugar + phosphate. Related to this Question. Record yourself saying 'uracil' in full sentences, then watch yourself and listen. Thymine is an organic aromatic. Become a Study. ]The RNA adds uracil (U) rather than thymine to adenine. [2] After transcription and following synthesis, RNA can be modified with over. Coordinate terms: citosina, timina. Cytosine forms three nitrogenous pair with guanine in the Watson-Crick model of DNA. "Uracil: Definition & Structure. The pyrimidines in DNA are cytosine and thymine; in RNA, they are cytosine and uracil. deviation, Use the word bank to answer the question. A pyrimidine is an organic compound known as an aromatic heterocyclic compound and has the molecular formula of C 4 H 4 N 2. 00:00. Related to this Question. In RNA it is abbreviated with a U. 4 /5. Uracil. Refine your pronunciation of uracil with our free online dictionary. It has a pyrimidine ring structure. The deoxyribonucleic acid (DNA) of a typical mammalian cell contains about 3 × 10 9 nucleotides. 2020;60(12):2034-2051. Transcription is the first step in gene expression. There are three major types of RNA involved in this process: (1) messenger RNA (mRNA), (2) transfer RNA (tRNA), and (3) ribosomal RNA (rRNA). (ˈjʊərəsɪl ) noun biochemistry a pyrimidine present in all living cells, usually in a combined form, as in RNA. noun uracil Biochemistry. Definition of Uracil. Pronunciation of uracil. Study with Quizlet and memorize flashcards containing terms like Definition of virulent, Definition of transformation, Definintion of bacteriophage and more. How to say uracil in English? Pronunciation of uracil with 2 audio pronunciations, 1 synonym, 1 meaning, 10 translations and more for uracil. Dihydropyrimidine dehydrogenase deficiency. How to say Fluorouracil in English? Pronunciation of Fluorouracil with 1 audio pronunciation and more for Fluorouracil. English (UK) Pronunciation: Catalan Pronunciation: Chinese (Mandarin) Pronunciation: Chinese (China) Pronunciation: Chinese (Hong Kong) Pronunciation: Chinese (Taiwan) Pronunciation: Danish Pronunciation:Uracil: Definition & Structure. DNA and RNA are very similar. Thymine: Thymine only occurs in DNA. It pairs with the adenine through hydrogen bonds. (b) RNA contains the pyrimidine uracil in place of thymine found in DNA. Definition of Uracil. The four nitrogenous bases in DNA. 2. Heterocyclic compounds are stable, ring-shaped compounds in which not. The ribose sugar of RNA is a cyclical structure consisting of five carbons and one oxygen. Etymology: The term “thymine” is derived from the Greek word “thumos,” meaning “spirit” or “soul,” due to its association with thymus glands. Chapter 11 / Lesson 9.