A base pair (bp) is a unit consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix, and contribute to the folded structure of both DNA
DNA and RNA. Dictated by specific hydrogen bonding patterns, Watson-Crick base pairs (guanine-cytosine and adenine-thymine) allow the DNA
DNA helix to maintain a regular helical structure that is subtly dependent on its nucleotide sequence.[1] The complementary nature of this based-paired structure provides a backup copy of all genetic information encoded within double-stranded DNA
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Enols, or more formally, alkenols, are a type of reactive structure or intermediate in organic chemistry that is represented as an alkene (olefin) with a hydroxyl group attached to one end of the alkene double bond. The terms enol and alkenol are portmanteaus deriving from "-ene"/"alkene" and the "-ol" suffix indicating the hydroxyl group of alcohols, dropping the terminal "-e" of the first term. Generation of enols often involves removal of a hydrogen adjacent (α-) to the carbonyl group—i.e., deprotonation, its removal as a proton, H+. When this proton is not returned at the end of the stepwise process, the result is an anion termed an enolate (see images at right). The enolate structures shown are schematic; a more modern representation considers the molecular orbitals that are formed and occupied by electrons in the enolate
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Molecular biology
Molecular biology /məˈlɛkjʊlər/ is a branch of biochemistry which concerns the molecular basis of biological activity between biomolecules in the various systems of a cell, including the interactions between DNA, RNA, and proteins and their biosynthesis, as well as the regulation of these interactions.[1] Writing in Nature in 1961, William Astbury described molecular biology as:"...not so much a technique as an approach, an approach from the viewpoint of the so-called basic sciences with the leading idea of searching below the large-scale manifestations of classical biology for the corresponding molecular plan. It is concerned particularly with the forms of biological molecules and [...] is predominantly three-dimensional and structural—which does not mean, however, that it is merely a refinement of morphology
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Ploidy
Ploidy is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Somatic cells, tissues and individuals can be described according to the number of sets present (the ploidy level): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid[1] or septaploid[2] (7 sets), etc. The generic term polyploid is used to describe cells with three or more chromosome sets.[3][4] Humans are diploid organisms, carrying two complete sets of chromosomes: one set of 23 chromosomes from their father and one set of 23 chromosomes from their mother. The two sets combined provide a full complement of 46 chromosomes. This total number of chromosomes is called the chromosome number. The zygotic number is defined as the number of chromosomes in zygotic cells
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The biosphere (from Greek βίος bíos "life" and σφαῖρα sphaira "sphere") also known as the ecosphere (from Greek οἶκος oîkos "environment" and σφαῖρα), is the worldwide sum of all ecosystems. It can also be termed the zone of life on Earth, a closed system (apart from solar and cosmic radiation and heat from the interior of the Earth), and largely self-regulating.[1] By the most general biophysiological definition, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, geosphere, hydrosphere, and atmosphere
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Carbon
Carbon (from Latin: carbo "coal") is a chemical element with symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table.[13] Three isotopes occur naturally, 12C and 13C being stable, while 14C is a radionuclide, decaying with a half-life of about 5,730 years.[14] Carbon
Carbon is one of the few elements known since antiquity.[15] Carbon
Carbon is the 15th most abundant element in the Earth's crust, and the fourth most abundant element in the universe by mass after hydrogen, helium, and oxygen. Carbon's abundance, its unique diversity of organic compounds, and its unusual ability to form polymers at the temperatures commonly encountered on Earth
Earth enables this element to serve as a common element of all known life
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The genetic code is the set of rules used by living cells to translate information encoded within genetic material ( DNA
DNA or m RNA
RNA sequences) into proteins. Translation is accomplished by the ribosome, which links amino acids in an order specified by messenger RNA
RNA (mRNA), using transfer RNA
RNA (tRNA) molecules to carry amino acids and to read the m RNA
RNA three nucleotides at a time. The genetic code is highly similar among all organisms and can be expressed in a simple table with 64 entries.[1] The code defines how sequences of nucleotide triplets, called codons, specify which amino acid will be added next during protein synthesis. With some exceptions,[2] a three-nucleotide codon in a nucleic acid sequence specifies a single amino acid. The vast majority of genes are encoded with a single scheme (see the RNA
RNA codon table)
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The term molecular recognition refers to the specific interaction between two or more molecules through noncovalent bonding such as hydrogen bonding, metal coordination, hydrophobic forces,[3][4] van der Waals forces, π-π interactions, halogen bonding, electrostatic and/or electromagnetic[5] effects. In addition to these direct interactions as well solvent can play a dominant indirect role in driving molecular recognition in solution.[6][7] The host and guest involved in molecular recognition exhibit molecular complementarity.[8][9]Contents1 Biological systems 2 Synthetic molecular recognition 3 Supramolecular systems 4 Static vs. dynamic 5 Complexity 6 See also 7 References 8 External linksBiological systems[edit] Molecular recognition
Molecular recognition plays an important role in biological systems and is observed in between receptor-ligand,[10][11] antigen-antibody, DNA-protein, sugar-lectin, RNA-ribosome, etc
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Messenger RNA
RNA (mRNA) is a large family of RNA
RNA molecules that convey genetic information from DNA
DNA to the ribosome, where they specify the amino acid sequence of the protein products of gene expression. RNA polymerase transcribes primary transcript m RNA
RNA (known as pre-mRNA) into processed, mature mRNA. This mature m RNA
RNA is then translated into a polymer of amino acids: a protein, as summarized in the central dogma of molecular biology. As in DNA, m RNA
RNA genetic information is in the sequence of nucleotides, which are arranged into codons consisting of three base pairs each. Each codon encodes for a specific amino acid, except the stop codons, which terminate protein synthesis
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An extremophile (from Latin extremus meaning "extreme" and Greek philiā (φιλία) meaning "love") is an organism that thrives in physically or geochemically extreme conditions that are detrimental to most life on Earth.[1][2] In contrast, organisms that live in more moderate environments may be termed mesophiles or neutrophiles.Contents1 Characteristics 2 Classifications2.1 Terms3 In astrobiology 4 Examples 5 Industrial uses 6 DNA transfer 7 See also 8 References 9 Further reading 10 External linksCharacteristics[edit] In the 1980s and 1990s, biologists found that microbial life has great flexibility for surviving in extreme environments—niches that are acidic or extraordinarily hot, for example—that would be completely inhospitable to complex organisms
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Thermus
Thermus thermophilus is a Gram negative eubacterium used in a range of biotechnological applications, including as a model organism for genetic manipulation, structural genomics, and systems biology. The bacterium is extremely thermophilic, with an optimal growth temperature of about 65 °C (149 °F). Thermus
Thermus thermophilus was originally isolated from a thermal vent within a hot spring in Izu, Japan
Japan by Tairo Oshima and Kazutomo Imahori.[1] The organism has also been found to be important in the degradation of organic materials in the thermogenic phase of composting.[2] T. thermophilus is classified into several strains, of which HB8 and HB27 are the most commonly used in laboratory environments. Genome analyses of these strains were independently completed in 2004.[3] Biotechnological applications of T
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RNA
RNA polymerase (ribonucleic acid polymerase), both abbreviated RNAP or RNApol, official name DNA-directed RNA
RNA polymerase, is a member of a family of enzymes that are essential to life: they are found in all organisms (-species) and many viruses. RNAP locally opens the double-stranded DNA
DNA (usually about four turns of the double helix) so that one strand of the exposed nucleotides can be used as a template for the synthesis of RNA, a process called transcription. A transcription factor and its associated transcription mediator complex must be attached to a DNA
DNA binding site called a promoter region before RNAP can initiate the DNA
DNA unwinding at that position. RNAP has intrinsic helicase activity, therefore no separate enzyme is needed to unwind the DNA
DNA (in contrast to DNA
DNA polymerase)
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A primer is a short strand of RNA
RNA or DNA
DNA (generally about 18-22 bases) that serves as a starting point for DNA
DNA synthesis. It is required for DNA
DNA replication because the enzymes that catalyze this process, DNA polymerases, can only add new nucleotides to an existing strand of DNA. The polymerase starts replication at the 3′-end of the primer, and copies the opposite strand. In vivo DNA
DNA replication utilizes short strands of RNA
RNA called RNA primers to initiate DNA
DNA synthesis on both the leading and lagging strands – DNA
DNA primers are not seen in vivo in humans
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Polymerase chain reaction
Polymerase chain reaction (PCR) is a technique used in molecular biology to amplify a single copy or a few copies of a segment of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA
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DNA sequence. Developed in 1983 by Kary Mullis,[1][2] who was an employee of the Cetus Corporation, and also the winner of Nobel Prize in Chemistry
Nobel Prize in Chemistry in 1993, it is an easy, cheap, and reliable way to repeatedly replicate a focused segment of DNA, a concept which is applicable to numerous fields in modern biology and related sciences.[3] PCR is probably the most widely used technique in molecular biology
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Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation, and expression of genes. RNA
RNA and DNA
DNA are nucleic acids, and, along with lipids, proteins and carbohydrates, constitute the four major macromolecules essential for all known forms of life. Like DNA, RNA
RNA is assembled as a chain of nucleotides, but unlike DNA
DNA it is more often found in nature as a single-strand folded onto itself, rather than a paired double-strand. Cellular organisms use messenger RNA
RNA (mRNA) to convey genetic information (using the nitrogenous bases guanine, uracil, adenine, and cytosine, denoted by the letters G, U, A, and C) that directs synthesis of specific proteins
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Classical Isosteres are molecules or ions with the similar shape and often electronic properties. Many definitions are available.[1] but the term is usually employed in the context of bioactivity and drug development. Such biologically-active compounds containing an isostere is called a bioisostere. This is frequently used in drug design:[2] the bioisostere will still be recognized and accepted by the body, but its functions there will be altered as compared to the parent molecule. History and additional definitions[edit] Non-classical isosteres do not obey the above classifications, but they still produce similar biological effects in vivo. Non-classical isosteres may be made up of similar atoms, but their structures do not follow an easily definable set of rules. The isostere concept was formulated by Irving Langmuir in 1919,[3] and later modified by Grimm
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