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Molecular biology is the study of biology at a molecular level. The field overlaps with other areas of biology, particularly genetics and biochemistry. Molecular biology chiefly concerns itself with understanding the interactions between the various systems of a cell, including the interrelationship of DNA, RNA and protein synthesis and learning how these interactions are regulated. Writing in Nature, W.T. 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 - it must at the same time inquire into genesis and function"
[Nature 190, 1124 (1961)]
1 Relationship to other "molecular-scale" biological sciences
Researchers in molecular biology use specific techniques native to molecular biology (see Techniques section later in article), but increasingly combine these with techniques and ideas from genetics, biochemistry and biophysics. There is not a hard-line between these disciplines as there once was. The following figure is a schematic that depicts one possible view of the relationship between the fields:
- Biochemistry is the study of molecules (e.g. proteins) in the absence of the rest of the organism. Biochemists take an organism or cell and dissect it into its molecular components, such as enzymes, lipids and DNA, and reconstitute them in test tubes (in vitro).
- Genetics is the study of the effect of genetic differences on organisms. Often this can be inferred by the absence of a normal component (e.g. one gene). The study of " mutants" – organisms which lack one or more functional components with respect to the so-called " wild type" or normal phenotype. Genetic interactionsGenetic interactions in genetics, are interactions that occur between two or more mutations that results in a new phenotype. Studying genetic interactions can reveal gene function, the nature of the mutations, functional redundancy, and protein interactio such as epistasisEpistasis is the masking of the phenotypic effects of one gene by alleles of another at another locus. A gene is epistatic when its presence suppresses the effect of the other gene. Epistatic genes are also known as inhibiting genes due to their effects o can often confound simple interpretations of such "knock-out" studies.
- Molecular biology is the study of molecular underpinnings of the process of replication, transcription and translation of the genetic materialGenetic material is the material used to store genetic information for a living organism. For all currently known living organisms, with the exception of prions, the genetic material is almost exclusively DNA. This is supplemented with cytoplasmic inherit. The central dogma of molecular biologyThe central dogma of molecular biology (sometimes Crick's central dogma after Francis Crick who coined the term and discovered some of the principles) states that the flow of genetic information is " DNA to RNA to protein". With a few notable exceptions, where genetic material is transcribed into RNA and then translated into protein, despite being an oversimplified picture of molecular biology, still provides a good starting point for understanding the field. This picture, however, is undergoing revision in light of emerging novel roles for RNARNA may also stand for the Republic of New Africa Ribonucleic acid RNA is a nucleic acid consisting of a string of covalently-bound nucleotides. It is biochemically distinguished from DNA by the presence of an additional hydroxyl group, attached to each p.
Much of the work in molecular biology is quantitative, and recently much work has been done at the interface of molecular biology and computer science in bioinformaticsBioinformatics or computational biology is the use of mathematical and informational techniques, including statistics, to solve biological problems, usually by creating or using computer programs, mathematical models or both. One of the main areas of bioi and computational biology. As of the early 2000s, the study of gene structure and function, molecular genetics, has been amongst the most prominent sub-field of molecular biology.
Increasingly many other fields of biology focus on molecules, either directly studying their interactions in their own right such as in cell biology and developmental biology, or indirectly, where the techniques of molecular biology are used to infer historical attributes of populations or species, as in fields in evolutionary biology such as population genetics and phylogenetics. There is also a long tradition of studying biomolecules "from the ground up" in biophysics.
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