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Aquaspirillum Serpens
''Aquaspirillum serpens'' is a species of gram-negative bacteria in the family Neisseriaceae. Description The surface of the cell of ''Aquaspirillum serpens'' has clear structures which take the form of linear bands at intervals of 17-18.5 nanometers (nm). There is also a variety of different patterns of ridges which surround protein subunits at the cell margin. Most of these consist of thin lines towards the edge of the cell wall, but they can be a hexagonal shape. The ridges are usually around 16 nm apart. Flagella ''Aquaspirillum serpens'' is propelled by fewer than fifteen flagella at each of its poles, or ends. The basal body, or protein structure at the base of the flagellum, consists of two pairs of disk-like structures. All of these disks are within the outer membrane of the bacterium. The outer pair of disks are very close to each other; the outermost is 18 nm in diameter and the more inner is 21 nm in diameter. The inner pair of disks have some form of membrane, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LPSN
List of Prokaryotic names with Standing in Nomenclature (LPSN) is an online database that maintains information on the naming and taxonomy of prokaryotes, following the taxonomy requirements and rulings of the International Code of Nomenclature of Prokaryotes The International Code of Nomenclature of Prokaryotes (ICNP) formerly the International Code of Nomenclature of Bacteria (ICNB) or Bacteriological Code (BC) governs the scientific names for Bacteria and Archaea.P. H. A. Sneath, 2003. A short hist .... The database was curated from 1997 to June 2013 by Jean P. Euzéby. From July 2013 to January 2020, LPSN was curated by Aidan C. Parte. In February 2020, a new version of LPSN was published as a service of the Leibniz Institute DSMZ, thereby also integrating the Prokaryotic Nomenclature Up-to-date service. References External links List of Prokaryotic names with Standing in Nomenclature [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-negative Bacteria
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane. Gram-negative bacteria are found in virtually all environments on Earth that support life. The gram-negative bacteria include the model organism ''Escherichia coli'', as well as many pathogenic bacteria, such as ''Pseudomonas aeruginosa'', '' Chlamydia trachomatis'', and ''Yersinia pestis''. They are a significant medical challenge as their outer membrane protects them from many antibiotics (including penicillin), detergents that would normally damage the inner cell membrane, and lysozyme, an antimicrobial enzyme produced by animals that forms part of the innate immune system. Additionally, the outer leaflet of this membrane comprises a complex lipopol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neisseriaceae
The Neisseriaceae are a family of Pseudomonadota, within the ''Neisseriales'' order. While many organisms in the family are mammalian commensals or part of the normal flora, the genus ''Neisseria'' includes two important human pathogens, specifically those responsible for gonorrhea (caused by'' N. gonorrhoeae'') and many cases of meningitis ("meningococcal meningitis", caused by'' N. meningitidis''). As a group, the Neisseriaceae are strictly aerobic and Gram-negative, occur mainly in pairs (diplococci A diplococcus (plural diplococci) is a round bacterium (a coccus) that typically occurs in the form of two joined cells. Types Examples of gram-negative diplococci are '' Neisseria spp.'' and ''Moraxella catarrhalis.'' Examples of gram-posit ...), and typically do not have flagella. References Bacteria of Medical Importancein ''Todar's Online Textbook of Bacteriology''. * * Betaproteobacteria {{Betaproteobacteria-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Subunit
In structural biology, a protein subunit is a polypeptide chain or single protein molecule that assembles (or "''coassembles''") with others to form a protein complex. Large assemblies of proteins such as viruses often use a small number of types of protein subunits as building blocks. A subunit is often named with a Greek or Roman letter, and the numbers of this type of subunit in a protein is indicated by a subscript. For example, ATP synthase has a type of subunit called α. Three of these are present in the ATP synthase molecule, leading to the designation α3. Larger groups of subunits can also be specified, like α3β3-hexamer and c-ring. Naturally-occurring proteins that have a relatively small number of subunits are referred to as oligomeric.Quote: ''Oligomer molecule: A molecule of intermediate relative molecular mass, the structure of which essentially comprises a small plurality of units derived, actually or conceptually, from molecules of lower relative molecular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquaspirillum Serpens Flagellum
''Aquaspirillum'' (ak'wă-spī-ril'ŭm) is a genus of helical aerobic bacteria in the family ''Neisseriaceae'' that lives in freshwater. Taxonomy In 1832, the genus ''Spirillum'' was created and encompassed an array of helical bacteria. In 1957, the large genus was reviewed and narrowed to include 19 species based on morphology and a few other physiological characteristics. The genus ''Aquaspirillum'' was not created until 1973, when another review of ''Spirillum'' led to the division of the genus into ''Aquaspirillum'', ''Oceanospirillum'', and ''Spirillum''. Etymology The genus' name is a combination of several words. ''Aqua'' comes from Latin, meaning water; ''speîra'' comes from Greek, meaning a spiral; ''spirillum'' come from Neo-Latin, meaning a small spiral. Put together, the genus' name means "small water spiral." Species The new genus comprised the following 13 species when it was created: *'' Aquaspirillum anulus'' *'' Aquaspirillum aquaticum'' * ''Aquaspirill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagellum
A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have from one to many flagella. A gram-negative bacterium ''Helicobacter pylori'' for example uses its multiple flagella to propel itself through the mucus lining to reach the stomach epithelium, where it may cause a gastric ulcer to develop. In some bacteria the flagellum can also function as a sensory organelle, being sensitive to wetness outside the cell. Across the three domains of Bacteria, Archaea, and Eukaryota the flagellum has a different structure, protein composition, and mechanism of propulsion but shares the same function of providing motility. The Latin word means " whip" to describe its lash-like swimming motion. The flagellum in archaea is called the archaellum to note its difference from the bacterial flagellum. Eukaryotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Body
A basal body (synonymous with basal granule, kinetosome, and in older cytological literature with blepharoplast) is a protein structure found at the base of a eukaryotic undulipodium (cilium or flagellum). The basal body was named by Theodor Wilhelm Engelmann in 1880 It is formed from a centriole and several additional protein structures, and is, essentially, a modified centriole. The basal body serves as a nucleation site for the growth of the axoneme microtubules. Centrioles, from which basal bodies are derived, act as anchoring sites for proteins that in turn anchor microtubules, and are known as the microtubule organizing center (MTOC). These microtubules provide structure and facilitate movement of vesicles and organelles within many eukaryotic cells. Assembly, structure Cilia and basal bodies form during quiescence or the G1 phase of the cell cycle. Before the cell enters G1 phase, i.e. before the formation of the cilium, the mother centriole serves as a component of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vestigiality
Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on comparison with homologous features in related species. The emergence of vestigiality occurs by normal evolutionary processes, typically by loss of function of a feature that is no longer subject to positive selection pressures when it loses its value in a changing environment. The feature may be selected against more urgently when its function becomes definitively harmful, but if the lack of the feature provides no advantage, and its presence provides no disadvantage, the feature may not be phased out by natural selection and persist across species. Examples of vestigial structures (also called degenerate, atrophied, or rudimentary organs) are the loss of functional wings in island-dwelling birds; the human vomeronasal organ; and the hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concentric Membrane Ring
In geometry, two or more objects are said to be concentric, coaxal, or coaxial when they share the same center or axis. Circles, regular polygons and regular polyhedra, and spheres may be concentric to one another (sharing the same center point), as may cylinders (sharing the same central axis). Geometric properties In the Euclidean plane, two circles that are concentric necessarily have different radii from each other.. However, circles in three-dimensional space may be concentric, and have the same radius as each other, but nevertheless be different circles. For example, two different meridians of a terrestrial globe are concentric with each other and with the globe of the earth (approximated as a sphere). More generally, every two great circles on a sphere are concentric with each other and with the sphere. By Euler's theorem in geometry on the distance between the circumcenter and incenter of a triangle, two concentric circles (with that distance being zero) are the circu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacculus (bacteria)
Sacculus may refer to: * Saccule, a bed of sensory cells in the inner ear * Sacculus (entomology), a sensory organ in the antenna of certain insects * Sacculus, a sac of peptidoglycan that has been purified from a gram-negative bacterium * Sacculus, the Latin word for money bag A money bag (or money sack) is a bag normally used to hold and transport coins and banknotes, often closed with a drawstring. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptidoglycan
Peptidoglycan or murein is a unique large macromolecule, a polysaccharide, consisting of sugars and amino acids that forms a mesh-like peptidoglycan layer outside the plasma membrane, the rigid cell wall (murein sacculus) characteristic of most bacteria (domain ''Bacteria''). The sugar component consists of alternating residues of β-(1,4) linked ''N''-acetylglucosamine (NAG) and ''N''-acetylmuramic acid (NAM). Attached to the ''N''-acetylmuramic acid is a oligopeptide chain made of three to five amino acids. The peptide chain can be cross-linked to the peptide chain of another strand forming the 3D mesh-like layer. Peptidoglycan serves a structural role in the bacterial cell wall, giving structural strength, as well as counteracting the osmotic pressure of the cytoplasm. This repetitive linking results in a dense peptidoglycan layer which is critical for maintaining cell form and withstanding high osmotic pressures, and it is regularly replaced by peptidoglycan production. Pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neisseriales
The Neisseriaceae are a family of Pseudomonadota, within the ''Neisseriales'' order. While many organisms in the family are mammalian commensals or part of the normal flora, the genus ''Neisseria'' includes two important human pathogens, specifically those responsible for gonorrhea (caused by'' N. gonorrhoeae'') and many cases of meningitis ("meningococcal meningitis", caused by'' N. meningitidis''). As a group, the Neisseriaceae are strictly aerobic and Gram-negative, occur mainly in pairs (diplococci A diplococcus (plural diplococci) is a round bacterium (a coccus) that typically occurs in the form of two joined cells. Types Examples of gram-negative diplococci are '' Neisseria spp.'' and ''Moraxella catarrhalis.'' Examples of gram-posit ...), and typically do not have flagella. References Bacteria of Medical Importancein ''Todar's Online Textbook of Bacteriology''. * * Betaproteobacteria {{Betaproteobacteria-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
