GenomeIn the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as regulatory sequences (see non-coding DNA), and often a substantial fraction of junk DNA with no evident function. Almost all eukaryotes have mitochondria and a small mitochondrial genome.
DNAMolecule that carries genetic informationThe structure of the DNA double helix (type B-DNA). The atoms in the structure are colour-coded by element and the detailed structures of two base pairs are shown in the bottom right.Simplified diagramDeoxyribonucleic acid (pronunciation; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix.
Molecular biologyMolecular biology is a branch of biology that seeks to understand the molecular structures and chemical processes that are the basis of biological activity within and between cells. It is centered largely on the study of nucleic acids (such as DNA and RNA) and proteins.
GeneSequence of DNA that determines traits in an organismIn biology, the word gene has two meanings. The Mendelian gene is a basic unit of . The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of RNA or protein from a gene), DNA is first copied into RNA.
GuanineNames Preferred IUPAC name2-Amino-1,9-dihydro-6H-purin-6-oneOther names 2-amino-6-hydroxypurine,2-aminohypoxanthine,GuanineIdentifiers CAS Number73-40-53D model (JSmol)keto form: Interactive imageenol form: Interactive imageBeilstein Reference147911 ChEBICHEBI:16235ChEMBLChEMBL219568ChemSpider744DrugBankDB02377ECHA InfoCard100.000.727EC Number200-799-8Gmelin Reference431879 IUPHAR/BPS4556KEGGC00242PubChemCID135398634RTECS numberMF8260000UNII5Z93L87A1RCompTox Dashboard(EPA)DTXSID9052476InChIInChI=1S/C5H5N5O/c6-5-9-3-2(4(11)10-5)7-1-8-3/h1H,(H4,6,7,8,9,10,11)Key: UYTPUPDQBNUYGX-UHFFFAOYSA-NInChI=1/C5H5N5O/c6-5-9-3-2(4(11)10-5)7-1-8-3/h1H,(H4,6,7,8,9,10,11)Key: UYTPUPDQBNUYGX-UHFFFAOYAESMILESketo form: N1C(N)=NC=2NC=NC2C1=Oenol form: OC1=C2N=CNC2=NC(=N1)NProperties Chemical formulaC5H5N5O Molar mass151.13 g/mol Appearance White amorphous solid.
AdenineNames Preferred IUPAC name9H-Purin-6-amineOther names 6-AminopurineIdentifiers CAS Number73-24-53D model (JSmol)Interactive imageInteractive imageBeilstein Reference608603 ChEBICHEBI:16708ChEMBLChEMBL226345ChemSpider185DrugBankDB00173ECHA InfoCard100.000.724EC Number200-796-1Gmelin Reference3903 IUPHAR/BPS4788KEGGD00034PubChemCID190RTECS numberAU6125000UNIIJAC85A2161CompTox Dashboard(EPA)DTXSID6022557InChIInChI=1S/C5H5N5/c6-4-3-5(9-1-7-3)10-2-8-4/h1-2H,(H3,6,7,8,9,10)Key: GFFGJBXGBJISGV-UHFFFAOYSA-NInChI=1/C5H5N5/c6-4-3-5(9-1-7-3)10-2-8-4/h1-2H,(H3,6,7,8,9,10)Key: GFFGJBXGBJISGV-UHFFFAOYATSMILESNC1=NC=NC2=C1N=CN2Nc1c2ncNc2ncn1Properties Chemical formulaC5H5N5Molar mass135.130 g·mol Appearance white to light yellow, crystalline Density1.6 g/cm (calculated) Melting point360 to 365 °C (680 to 689 °F; 633 to 638 K) decomposes Solubility in water0.103 g/100 mL Solubilitynegligible in ethanol, soluble in hot water and/or aqua ammoniaAcidity (pKa) 4.15 (secondary), 9.80 (primary) Thermochemistry Heat capacity(C)147.0 J/(K·mol) Std enthalpy offormation(ΔfH298)96.9 kJ/mol Hazards Lethal dose or concentration (LD, LC): LD50 (median dose)227 mg/kg (rat, oral) Safety data sheet (SDS) MSDSExcept where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).Yverify ( ?)
RNAFamily of large biological moleculesA hairpin loop from a pre-mRNA. Highlighted are the nucleobases (green) and the ribose-phosphate backbone (blue). This is a single strand of RNA that folds back upon itself. Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA).
GeneticsGenetics is the study of genes, genetic variation, and heredity in organisms. It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time.
CytosineCytosine (symbol C or Cyt) is one of the four nucleotide bases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group at position 2). The nucleoside of cytosine is cytidine. In Watson–Crick base pairing, it forms three hydrogen bonds with guanine.
ThymineNames Preferred IUPAC name5-Methylpyrimidine-2,4(1H,3H)-dioneOther names 5-MethyluracilIdentifiers CAS Number65-71-43D model (JSmol)Interactive imageChEBICHEBI:17821ChEMBLChEMBL993ChemSpider1103ECHA InfoCard100.000.560IUPHAR/BPS4581MeSHThyminePubChemCID1135UNIIQR26YLT7LTCompTox Dashboard(EPA)DTXSID4052342InChIInChI=1S/C5H6N2O2/c1-3-2-6-5(9)7-4(3)8/h2H,1H3,(H2,6,7,8,9)Key: RWQNBRDOKXIBIV-UHFFFAOYSA-NSMILESO=C1NC(=O)NC=C1CProperties Chemical formulaC5H6N2O2Molar mass126.115 g·mol Density1.223 g cm (calculated) Melting point316 to 317 °C (601 to 603 °F; 589 to 590 K) Boiling point335 °C (635 °F; 608 K) (decomposes) Solubility in water3.82 g/L Acidity (pKa) 9.7 Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).Thymine () (symbolT or Thy) is one of the four nucleotide bases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine.
UracilNames Preferred IUPAC namePyrimidine-2,4(1H,3H)-dioneOther names 2-Oxy-4-oxypyrimidine2,4(1H,3H)-Pyrimidinedione2,4-Dihydroxypyrimidine2,4-PyrimidinediolIdentifiers CAS Number66-22-83D model (JSmol)lactam form: Interactive imagelactim form: Interactive imageBeilstein Reference606623 ChEBICHEBI:17568ChEMBLChEMBL566ChemSpider1141DrugBankDB03419ECHA InfoCard100.000.565EC Number200-621-9Gmelin Reference2896 IUPHAR/BPS4560KEGGC00106PubChemCID1174RTECS numberYQ8650000UNII56HH86ZVCTCompTox Dashboard(EPA)DTXSID4021424InChIInChI=1S/C4H4N2O2/c7-3-1-2-5-4(8)6-3/h1-2H,(H2,5,6,7,8)Key: ISAKRJDGNUQOIC-UHFFFAOYSA-NSMILESlactam form: O=C1C=CNC(=O)N1lactim form: Oc1nccc(O)n1Properties Chemical formulaC4H4N2O2Molar mass112.08676 g/mol Appearance Solid Density1.32 g/cm Melting point335 °C (635 °F; 608 K) Boiling pointN/A – decomposes Solubility in waterSoluble Hazards Occupational safety and health (OHS/OSH): Main hazardscarcinogen and teratogen with chronic exposure GHS labelling: PictogramsSignal wordWarningHazard statementsH315, H319, H335, H361Precautionary statementsP201, P202, P261, P264, P271, P280, P281, P302+P352, P304+P340, P305+P351+P338, P308+P313, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501NFPA 704 (fire diamond) 11Flash pointNon-flammable Related compounds Related compoundsThymineCytosineExcept where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).Nverify ( ?)
Nucleotide baseNucleotide 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 deoxyribonucleic acid (DNA).*As an Amazon Associate I earn from qualifying purchases.