model

X-ray crystallography

...e electron density. After phases are estimated, a model made up of atoms is built and refined against the observed data. Once a model of a molecule's structure has been determined, it is often deposited in a crystallographic database ...

Virus evolution

... of the treatment. RNA viruses are also used as a model system to study evolution in the laboratory. One ...dels to study virus evolution is the quasispecies model . See also Viral classification RNA virus DNA virus Further reading E. Domingo a...

Transformation

...he operations of moving, scaling, or rotating a 3D model are commonly called transformations. See linear transformation , transformation geometry , transformation group ; also infinitesimal transformation . In music , a transformation is any operation or process that may be applied to a musical var...

Tobacco mosaic virus

...onth at Berkeley , and later designed and built a model of TMV for the 1958 World's Fair at Brussels . In 1958 , she speculated that the virus was hollow, not solid, and hypothesized that the RNA of TMV is single-stranded. This conjecture was proven to be correct after her death. Tobacco mosaic vir...

Tobacco mosaic virus

...onth at Berkeley , and later designed and built a model of TMV for the 1958 World's Fair at Brussels . In 1958 , she speculated that the virus was hollow, not solid, and hypothesized that the RNA of TMV is single-stranded. This conjecture was proven to be correct after her death. Tobacco mosaic vir...

Thomas Hunt Morgan

...of his work, Drosophila became one of the major model organisms in genetics. Biography Morgan was born in Lexington, Kentucky . Morgan received his bachelor's degree from the University of Kentucky in 1886 and his master's degree in 1888 . The Thomas Hunt Morgan School of Biological Scienc...

Systems biology

...tc.) it is hoped that eventually an understandable model of the whole system can be developed. Nevertheles... computer simulation gene regulatory network model signalomics Important publications in systems biology Bibliography Gregory Bock and Jam...

Prion

...tic PrP SC protein, confirming the "protein only" model for prion disease. Although the identity and gene...ier to transmission. The figure at right shows a model of two conformations of PrP; on the left is the normal, alpha helical form, while on the right is ...

Population dynamics

...e Malthusian demograhical model. A more general model formulation was proposed by F.J. Richards in 1959 , by which the models of Gompertz, Verhulst and also Ludwig von Bertalanffy are covered as special cases of the general formulation.The computer game SimCity tries to simulate some of these ...

Origin of life

...y of the origin of life 3.2 "Deep-hot biosphere" model of Gold 3.3 "Primitive" extraterrestrial life ...f the origin of life There is no truly "standard" model of the origin of life, however most currently accepted models build in one way or another upon the f...

Nutrition

...mstances of the individual. However, the holistic model of nutrition points out that for example high energy needs can be met in various ways, some more healthful than others. Food energy can be obtained from most foods, and are probably best obtained from those foods which have as high a concentration o...

Neurospora crassa

... axons . N. crassa is notable for its use as a model organism in science because it is easy to grow and has a haploid life cycle that makes genetic analysis simple since recessive traits will show up in the offspring. Neurospora was used by Edward Tatum and George Wells Beadle in their exper...

Mycology

...nderstood fungi are the yeasts and eukaryotic model organisms Saccharomyces cerevisiae and Schizosaccharomyces pombe . Many fungi produce toxins , antibiotics , and other secondary metabolites . For example, the cosmopolitian (worldwide) genus Fusarium and their toxins associated with ...

Morphogenesis

...lutants. See also embryogenesis embryo model organism Drosophila embryogenesis Alan Turing...

Modern evolutionary synthesis

...n of Mendelian Inheritance ", which showed using a model how continuous variation could be the result of the action of many discrete loci . This is generally regarded as the starting point of the synthesis. Tenets of the modern synthesis According to the modern synthesis as established in the 1930s ...

Molecular evolution

...ny 2.4 The neutral theory 2.5 Infinite alleles model 2.6 Infinite sites model 3 Related fields 4 See also 5 References 6 External links Exceptions to the...

Microbiology

... . Microbes have many traits that make them ideal model organisms : They are small, therefore they do not consume many resources Some have very short generation times (the time needed for division of a bacterial cell in two in optimal conditions; ~30 minutes for E. coli , but 12 to 24 hours for M...

Metapopulation

...s coined by Richard Levins in 1969 to describe a model of population dynamics of insect pests in agricult...f Helsinki . The Levins Model Levins' original model applied to a metapopulation distributed over many patches of suitable habitat with significantly les...

Mathematical biology

...formula , Lotka-Volterra equation , mathematical model , morphometrics , population dynamics , population genetics , theoretical biology . External links Society for Mathematical Biology European Society for Mathematical and Theoretical Biology Centre for Mathematical Biology at Oxford U...

Lipase

...ic lipase (PLRP2) from the guinea pig, it is a 3-D model from structure coordinates submitted to the Protein Data Bank from: Withers-Martinez, C., F. Carriere, R. Verger, D. Bourgeois, and C. Cambillau. 1996. A pancreatic lipase with a phospholipase A1 activity: crystal structure of a chimeric pancreati...

Life

...e: Origin of life There is no truly "standard" model of the origin of life, however most currently accepted models build in one way or another upon the following discoveries, which are listed in a rough order of postulated emergence: Plausible pre-biotic conditions result in the creation of the basic...

Konrad Lorenz

...nz further developed this into a "Psychohydraulic" model of the motivation of behaviour. These ideas were influential as ethology became more popular in the 1960s, but they are now regarded as outdated because of their use of an energy flow metaphor; the nervous system and the control of behaviour are n...

Intron

...f genes such as the actins . In the introns-early model ancestral genes are believed to have included a la...lated genes of different species. The introns-late model suggests instead that introns occur in the same location in variants of a given gene because the loc...

Immune system

...ished. Earlier studies of innate immunity utilized model organisms that lack adaptive immunity such as the plant Arabidopsis thaliana , the fly Drosophila melanogaster , and the worm Caenorhabditis elegans . Recent advances have been made in the field of innate immunology with the discovery of th...

Human Genome Project

...ne are predicted as a result of the sequencing of model organisms including mice, fruitflies, zebrafish, yeast, nematodes and many microbial organisms and parasites. In October 2004 , researchers of the HGP announced a new estimate of 20,000 to 25,000 genes in the human genome . Previously 30,000 ...

Homeobox

...mammals . The diagram to the right is a structural model of the Rattus norvegicus Pit-1 homeobox-containing protein (purple) bound to DNA. Pit-1 is a regulator of growth hormone gene transcription. Pit-1 is a member of the POU DNA-binding domain family of transcription factors so it can bind to DNA u...

HeLa

...ies from normal cervical cells. They are used as model cancer cells and for studying cellular signal transduction . HeLa cells have proven difficult to control. They sometimes contaminate other cell cultures growing in the same laboratory, interfering with biological research. The degree of contamina...

Genome project

...Takifugu rubipres A pufferfish See also model organism International HapMap Project UniProt External links National Center for Biotechnology Information Genome Project Database...

Gene regulatory network

...ng example illustrates how a Boolean network can model a GRN together with its gene products (the outputs...logists to use the metaphor of Boolean networks to model genetic regulatory networks. Each gene, each input, and each output is represented by a node in a ...

Extinction

...on genetics External links A mathematical model for mass extinction Species disappearing at an alarming rate (MSNBC) Red List of Threatened Species References Mass Extinction Underway | Biodiversity Crisis | Global Species Loss Univ. of Arizona lecture on extinction...

Evolutionary developmental biology

...he discovery of genes regulating development in model organisms allowed for comparisons to be made with genes and genetic networks of related organisms. Contents showTocToggle("show","hide") 1 Introduction 2 Development and the origin of novelty 3 References 4 Further reading ...

Evolution

...opinion". In contrast, a scientific theory is a model of the world (or some portion of it) from which f...combined approach, applying a rigorous statistical model to Mendel's theories of inheritance via genes, became known in the 1930s and 1940s as the modern sy...

Eugenics

...ns (though neither he nor Darwin had yet a working model of this type of heredity), and that just as one co..., however, these had been reconciled into a single model by the work of Ronald Fisher , who developed more powerful statistical models based on the Mendelia...

Enzyme

... 2.4 Metabolic pathways 2.5 Quantum-mechanical model of enzyme catalysis 3 Ribozymes 4 Enzymes...product made by the pathway. Quantum-mechanical model of enzyme catalysis The lecture "Quantum Theory of some Biochemical Reactions", presented to the IV...

Morphogenesis

...lutants. See also embryogenesis embryo model organism Drosophila embryogenesis Alan Turing...

Escherichia coli

...e Enterobacteriaceae , and is commonly used as a model organism for bacteria in general. The number of individual E. coli bacteria in the feces that one human passes in one day averages 10 11 (= one with eleven zeroes after it) to 10 13 . All the different kinds of fecal coli bacteria and...

Drosophila

...ly used in research in genetics and is a common model organism in developmental biology . Indeed, the terms "fruit fly" and " Drosophila " are often used synonymously with D. melanogaster in modern biological literature. This article however deals with the whole genus. Contents showTocToggle(...

Down syndrome

...5Dn (segmental trisomy 16 mouse) as an excellent model for studying the Down syndrome. Ts65Dn mouse has g...o the human chromosome 21 genes. With this animal model , the exact causes of Down syndrome neurological symptoms may soon be elucidated. Naturally, Ts65Dn...

DNA

...ur in equal proportions 9.3.3 Watson and Crick's model 9.3.4 Publishing of the "Central Dogma" 10...sent in equal proportions. Watson and Crick's model Watson and Crick had begun to contemplate double helical arrangements, and they saw that by reversi...

Developmental biology

...ular mechanisms of development 2 Developmental model organisms 3 See also 4 External links ...udiment , teratology , zygote Developmental model organisms Often used model organisms in developmental biology include the following: Chordates...

Culture

...n of innovations theory presents a research-based model for how, when and why people adopt new ideas. All...s of innovations theory presents a research-based model for why and when individuals and cultures adopt new ideas, practices, and products. "Acculturation"...

Cladistics

...highest likelihood based on a specific probability model of changes. Cladistics has taken a while to settle in, and there is still wide debate over how to apply Hennig's ideas in the real world. In particular, apomorphies are not always easy to distinguish and data are often unavailable due to a sparsity...

Cancer

...divide less, for example neurons . In cellular model systems , cells are exposed to carcinogenic influences (chemicals, radiation). In these systems, the first signs of a cell developing into a tumor cell are: Immortality. The usual number of cell divisions for a mammalian cell is 50-60 (cell senesc...

Botany

... knowledge today is being generated from studying model plants like Arabidopsis thaliana . This mustar... (a single-celled, green alga ) is another plant model organism that has been extensively studied and provided important insights into cell biology. Ear...

Biophysics

...), biophysicists are able to indirectly observe or model the structures and interactions of individual molecules or complexes of molecules. In addition things like solving a protein structure or measuring the kinetics of single molecule interactions, biophysics is also understood to encompass resea...

Biomechanics

... Continuum Mechanics It is often appropriate to model living tissues as continuous media. For example, a...tics and constitutive relations are also needed to model a continuum. Second and fourth order tensors are crucial in representing many quantities in biomech...

ATP synthase

... was able to determine that Boyer's conformational model was essentially correct. In the crystal structure, the F 1 particle can be seen to be composed of a cylinder of 6 subunits , alternating alpha and beta subunits, that form a ring around an asymmetrical gamma subunit. Facilitated diffusion of proto...

Artificial life

...henomena. The usual way is through an agent based model , which usually gives a minimal possible solution....rated basic self-replication in the 1950s with a model train set -- a seed "organism" consisting of a "head" and "tail" boxcar could use the simple rules o...

Arabidopsis

...le Cress ( Arabidopsis thaliana ), are one of the model organisms for studying plant sciences, including g...ouse and fruit fly ( Drosophila ) are used as model organisms to understand human biology, Arabidopsis thaliana is used to study agronomic crops. T...

Anton van Leeuwenhoek

...ies ago. He is thought by some to have been the model for Vermeer 's painting The Geographer (Stadelsches Kunstinstitut, Frankfurt-am-Main). Vermeer and van Leeuwenhoek were baptised the same month, in the same church. After Vermeer died, van Leeuwenhoek was appointed curator for the financial affair...

Allostery

...e") 1 Models of allostery 1.1 Concerted model 1.2 Sequential model 2 Allosteric activation 3 Allosteric inhibition 4 Related topics Models of all...

Allostery

...e") 1 Models of allostery 1.1 Concerted model 1.2 Sequential model 2 Allosteric activation 3 Allosteric inhibition 4 Related topics Models of all...

Active site

...veral models of how enzymes work. The lock and key model and the induced fit model whereby the active site binds and encloses the substrate molecule. Often enzymes bond to their subst...