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Degeneracy (biology)
Within biological systems, degeneracy occurs when structurally dissimilar components/pathways can perform similar functions (i.e. are effectively interchangeable) under certain conditions, but perform distinct functions in other conditions. Degeneracy is thus a relational property that requires comparing the behavior of two or more components. In particular, if degeneracy is present in a pair of components, then there will exist conditions where the pair will appear functionally redundant but other conditions where they will appear functionally distinct. Note that this use of the term has practically no relevance to the questionably meaningful concept of evolutionarily Devolution (biology), degenerate populations that have lost Ancestor, ancestral functions. Biological examples Examples of degeneracy are found in the genetic code, when many different nucleotide sequences encode the same polypeptide; in protein folding, when different polypeptides fold to be structurally and funct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Trait
A phenotypic trait, simply trait, or character state is a distinct variant of a phenotype, phenotypic characteristic of an organism; it may be either heredity, inherited or determined environmentally, but typically occurs as a combination of the two.Lawrence, Eleanor (2005) ''Henderson's Dictionary of Biology''. Pearson, Prentice Hall. For example, having eye color is a ''character'' of an organism, while blue, brown and hazel versions of eye color are ''traits''. The term ''trait'' is generally used in genetics, often to describe the phenotypic expression of different combinations of alleles in different individual organisms within a single Population genetics, population, such as the famous purple vs. white flower coloration in Gregor Mendel's pea plants. By contrast, in systematics, the term ''character state'' is employed to describe features that represent fixed diagnostic differences among taxa, such as the absence of tails in great apes, relative to other primate group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolvability
Evolvability is defined as the capacity of a system for adaptive evolution. Evolvability is the ability of a population of organisms to not merely generate genetic diversity, but to generate '' adaptive'' genetic diversity, and thereby evolve through natural selection. In order for a biological organism to evolve by natural selection, there must be a certain minimum probability that new, heritable variants are beneficial. Random mutations, unless they occur in DNA sequences with no function, are expected to be mostly detrimental. Beneficial mutations are always rare, but if they are too rare, then adaptation cannot occur. Early failed efforts to evolve computer programs by random mutation and selection showed that evolvability is not a given, but depends on the representation of the program as a data structure, because this determines how changes in the program map to changes in its behavior. Analogously, the evolvability of organisms depends on their genotype–phenotype map. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relationships Between Degeneracy, Complexity, Robustness, And Evolvability
Relationship most often refers to: * Family relations and relatives ** consanguinity * Interpersonal relationship, a strong, deep, or close association or acquaintance between two or more people * Correlation and dependence, relationships in mathematics and statistics between two variables or sets of data * Semantic relationship, an ontology component * Romance (love), a connection between two people driven by love and/or sexual attraction Relationship or Relationships may also refer to: Arts and media * "Relationship" (song), by Young Thug featuring Future * "Relationships" (''As Time Goes By''), an episode of the British TV series ''As Time Goes By'' * The Relationship, an American rock band ** ''The Relationship'' (album), their 2010 album * The Relationships, an English band who played at the 2009 Truck Festival * ''Relationships'', a 1994 album by BeBe & CeCe Winans * ''Relationships'', a 2001 album by Georgie Fame * "Relationship", a song by Lakeside on the 1987 albu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor Tyrosine Kinase
Receptor tyrosine kinases (RTKs) are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase proteins. Receptor tyrosine kinases have been shown not only to be key regulators of normal cellular processes but also to have a critical role in the development and progression of many types of cancer. Mutations in receptor tyrosine kinases lead to activation of a series of signalling cascades which have numerous effects on protein expression. The receptors are generally activated by dimerization and substrate presentation. Receptor tyrosine kinases are part of the larger family of protein tyrosine kinases, encompassing the receptor tyrosine kinase proteins which contain a transmembrane domain, as well as the non-receptor tyrosine kinases which do not possess transmembrane domains. History The first RTKs to be discovered were the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coactivation (Transcription)
A coactivator is a type of transcriptional coregulator that binds to an activator (a transcription factor) to increase the rate of transcription of a gene or set of genes. The activator contains a DNA binding domain that binds either to a DNA promoter site or a specific DNA regulatory sequence called an enhancer. Binding of the activator-coactivator complex increases the speed of transcription by recruiting general transcription machinery to the promoter, therefore increasing gene expression. The use of activators and coactivators allows for highly specific expression of certain genes depending on cell type and developmental stage. Some coactivators also have histone acetyltransferase (HAT) activity. HATs form large multiprotein complexes that weaken the association of histones to DNA by acetylating the N-terminal histone tail. This provides more space for the transcription machinery to bind to the promoter, therefore increasing gene expression. Activators are found in all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EGF Receptor
The epidermal growth factor receptor (EGFR; ErbB-1; HER1 in humans) is a transmembrane protein that is a receptor for members of the epidermal growth factor family (EGF family) of extracellular protein ligands. The epidermal growth factor receptor is a member of the ErbB family of receptors, a subfamily of four closely related receptor tyrosine kinases: EGFR (ErbB-1), HER2/neu (ErbB-2), Her 3 (ErbB-3) and Her 4 (ErbB-4). In many cancer types, mutations affecting EGFR expression or activity could result in cancer. Epidermal growth factor and its receptor was discovered by Stanley Cohen of Vanderbilt University. Cohen shared the 1986 Nobel Prize in Medicine with Rita Levi-Montalcini for their discovery of growth factors. Deficient signaling of the EGFR and other receptor tyrosine kinases in humans is associated with diseases such as Alzheimer's, while over-expression is associated with the development of a wide variety of tumors. Interruption of EGFR signalling, either b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cancer
Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible Signs and symptoms of cancer, signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in defecation, bowel movements. While these symptoms may indicate cancer, they can also have other causes. List of cancer types, Over 100 types of cancers affect humans. Tobacco use is the cause of about 22% of cancer deaths. Another 10% are due to obesity, poor Diet (nutrition), diet, sedentary lifestyle, lack of physical activity or Alcohol abuse, excessive alcohol consumption. Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. infectious causes of cancer, Infection with specific viruses, bacteria and parasites is an environmental factor cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolic Pathway
In biochemistry, a metabolic pathway is a linked series of chemical reactions occurring within a cell (biology), cell. The reactants, products, and Metabolic intermediate, intermediates of an enzymatic reaction are known as metabolites, which are modified by a sequence of chemical reactions catalyzed by enzymes. In most cases of a metabolic pathway, the product (chemistry), product of one enzyme acts as the substrate (chemistry), substrate for the next. However, side products are considered waste and removed from the cell. Different metabolic pathways function in the position within a Eukaryotic Cell, eukaryotic cell and the significance of the pathway in the given compartment of the cell. For instance, the electron transport chain and oxidative phosphorylation all take place in the mitochondrial membrane. In contrast, glycolysis, pentose phosphate pathway, and Fatty acid synthesis, fatty acid biosynthesis all occur in the cytosol of a cell. There are two types of metabolic pathw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolism
Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the conversion of food to building blocks of proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of metabolic wastes. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their Structures#Biological, structures, and respond to their environments. The word ''metabolism'' can also refer to the sum of all chemical reactions that occur in living organisms, including digestion and the transportation of substances into and between different cells, in which case the above described set of reactions within the cells is called intermediary (or intermediate) metabolism. Metabolic reactions may be categorized as ''catabolic''—the ''breaking down'' of compounds (for example, of glucose to pyruvate by c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saccharomyces
''Saccharomyces'' is a genus of fungi that includes many species of yeasts. ''Saccharomyces'' is from Greek σάκχαρον (sugar) and μύκης (fungus) and means ''sugar fungus''. Many members of this genus are considered very important in food production where they are known as brewer's yeast, baker's yeast and sourdough starter among others. They are unicellular and saprotrophic fungi. One example is ''Saccharomyces cerevisiae'', which is used in making bread, wine, and beer, and for human and animal health. Other members of this genus include the wild yeast '' Saccharomyces paradoxus'' that is the closest relative to ''S. cerevisiae'', '' Saccharomyces bayanus'', used in making wine, and ''Saccharomyces cerevisiae'' var. ''boulardii'', used in medicine. Morphology Colonies of ''Saccharomyces'' grow rapidly and mature in three days. They are flat, smooth, moist, glistening or dull, and cream in color. The inability to use nitrate and ability to ferment various carbohydrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adhesin Molecule (immunoglobulin -like)
In molecular biology, the adhesin molecule (immunoglobulin-like) is a protein domain. This domain is found in mucosal vascular addressin cell adhesion molecule 1 proteins (MAdCAM-1). These are cell adhesion molecules expressed on the endothelium in mucosa that guide the specific homing of lymphocytes into mucosal tissues. MAdCAM-1 belongs to a subclass of the immunoglobulin superfamily (IgSF), the members of which are ligands for integrins. The crystal structure of this domain has been reported; it adopts an immunoglobulin-like beta-sandwich structure, with seven strands arranged in two beta-sheets in a Greek-key topology. See also *Bacterial adhesin *Cell adhesion Cell adhesion is the process by which cells interact and attach to neighbouring cells through specialised molecules of the cell surface. This process can occur either through direct contact between cell surfaces such as Cell_junction, cell junc ... * Fungal adhesin References {{InterPro content, IPR015169 Pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
