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Antiporters
An antiporter (also called exchanger or counter-transporter) is a cotransporter and integral membrane protein involved in secondary active transport of two or more different molecules or ions across a phospholipid membrane such as the plasma membrane in opposite directions, one into the cell and one out of the cell. Na+/H+ antiporters have been reviewed. In secondary active transport, one species of solute moves along its electrochemical gradient, allowing a different species to move against its own electrochemical gradient. This movement is in contrast to primary active transport, in which all solutes are moved against their concentration gradients, fueled by ATP. Transport may involve one or more of each type of solute. For example, the Na+/Ca2+ exchanger, found in the plasma membrane of many cells, moves three sodium ions in one direction, and one calcium ion in the other. Role in Homeostatic Mechanisms Na+/H+ Antiporters Antiporters, such as Na+/H+ antiporter protein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiporter
An antiporter (also called exchanger or counter-transporter) is a cotransporter and integral membrane protein involved in secondary active transport of two or more different molecules or ions across a phospholipid membrane such as the plasma membrane in opposite directions, one into the cell and one out of the cell. Na+/H+ antiporters have been reviewed. In secondary active transport, one species of solute moves along its electrochemical gradient, allowing a different species to move against its own electrochemical gradient. This movement is in contrast to primary active transport, in which all solutes are moved against their concentration gradients, fueled by ATP. Transport may involve one or more of each type of solute. For example, the Na+/Ca2+ exchanger, found in the plasma membrane of many cells, moves three sodium ions in one direction, and one calcium ion in the other. Role in Homeostatic Mechanisms Na+/H+ Antiporters Antiporters, such as Na+/H+ antiporter protei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cotransporter
Cotransporters are a subcategory of membrane transport proteins (transporters) that couple the favorable movement of one molecule with its concentration gradient and unfavorable movement of another molecule against its concentration gradient. They enable active transport#Secondary active transport, coupled or cotransport (secondary active transport) and include antiporters and symporters. In general, cotransporters consist of two out of the three classes of integral membrane proteins known as transporters that move molecules and ions across biomembranes. Uniporters are also transporters but move only one type of molecule down its concentration gradient and are not classified as cotransporters. Background Cotransporters are capable of moving solutes either up or down gradients at rates of 1000 to 100000 molecules per second. They may act as channels or transporters, depending on conditions under which they are assayed. The movement occurs by binding to two molecules or ions at a ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Active Transport
In cellular biology, ''active transport'' is the movement of molecules or ions across a cell membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement. There are two types of active transport: primary active transport that uses adenosine triphosphate ( ATP), and secondary active transport that uses an electrochemical gradient. Some examples of active transport include: * Phagocytosis of bacteria by macrophages * Movement of calcium ions out of cardiac muscle cells * Transportation of amino acids across the intestinal lining in the human gut * Secretion of proteins such as enzymes, peptide hormones, and antibodies from various cells * Functioning of white blood cells to defend invading diseases Active cellular transportation (ACT) Unlike passive transport, which uses the kinetic energy and natural entropy of molecules moving down a gradient, active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Active Transport
In cellular biology, ''active transport'' is the movement of molecules or ions across a cell membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement. There are two types of active transport: primary active transport that uses adenosine triphosphate ( ATP), and secondary active transport that uses an electrochemical gradient. Some examples of active transport include: * Phagocytosis of bacteria by macrophages * Movement of calcium ions out of cardiac muscle cells * Transportation of amino acids across the intestinal lining in the human gut * Secretion of proteins such as enzymes, peptide hormones, and antibodies from various cells * Functioning of white blood cells to defend invading diseases Active cellular transportation (ACT) Unlike passive transport, which uses the kinetic energy and natural entropy of molecules moving down a gradient, active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium–hydrogen Antiporter
The sodium–hydrogen antiporter or sodium–proton exchanger (Na+/H+ exchanger) is a membrane protein that transports Na+ into the cell, and H+ out of the cell ( antiport). Function They are found in the membranes of many cells, and especially in those of the nephron of the kidney, specifically in the intercalary cells of the collecting duct and in the epithelial cells of the proximal convoluted tubule. The membrane pump is primarily responsible for maintaining homeostasis of pH and sodium. Defects in Na+/H+ antiporters may result in heart or kidney failure. Angiotensin II upregulates this antiporter in the proximal convoluted tubule in order to promote Na+ reabsorption and H+ secretion. Na+/H+ exchangers are thought to be implicated in other disorders such as hypertension. In one study, transgenic mice over expressing this membrane protein were shown to have increased reabsorption and retention of sodium after increased salt intake. In dopamine receptor signalling, the wide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uniporter
A uniporter is a membrane transport protein that transports a single species of Substrate (biochemistry), substrate (Electric charge, charged or uncharged) across a cell membrane. It may use either facilitated diffusion and transport along a diffusion gradient or transport against one with an active transport process. Uniporters include both carriers and ion channels, and are referred to as facilitated transporters, suggesting movement down a concentration or electrochemical gradient. Uniporter carrier proteins work by binding to one molecule of substrate (biochemistry), substrate at a time. Uniporter channels open in response to a stimulus and allow the free flow of specific molecules. There are several ways in which the opening of uniporter channels may be regulated: # Voltage – Regulated by the difference in voltage across the membrane # Stress (physics), Stress – Regulated by physical pressure on the transporter (as in the cochlea of the ear) # Ligand – Regulated by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porters
Porters may refer to: * Porters, Virginia, an unincorporated community in Virginia, United States * Porters, Wisconsin, an unincorporated community in Wisconsin, United States * Porters Ski Area, a ski resort in New Zealand * ''Porters'' (TV series), a British TV series See also * *Miss Porter's School Miss Porter's School (MPS) is an elite American private college preparatory school for girls founded in 1843, and located in Farmington, Connecticut. The school draws students from 21 states, 31 countries (with dual-citizenship and/or residence), ..., also known as Porter's, a school in Connecticut, United States * Porter (other) {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in carbohydrate molecules, such as sugars and starches, which are synthesized from carbon dioxide and water – hence the name ''photosynthesis'', from the Greek ''phōs'' (), "light", and ''synthesis'' (), "putting together". Most plants, algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies most of the energy necessary for life on Earth. Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centers that contain green chlorophyll (and other colored) pigments/chromoph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NhaD Family
The NhaD familyTC# 2.A.62 belongs to the Ion Transporter (IT) Superfamily. A representative list of proteins belonging to the NhaD family can be found in thTransporter Classification Database The NhaD Na+/H+ antiporter has been characterized from two ''Vibrio'' species: '' V. parahaemolyticus'' and '' V. cholerae'' and in the haloalkaliphile, '' Alkalimonas amylolytica''. These proteins and their homologues are 400-500 aas long and exhibit 10-13 TMSs. They catalyze Na+/H+ and Li+/H+ antiport. They exhibit activity at basic pH (8-10) with no activity at pH 7.5. The ''Amylolytica'' antiporter has low Na+ affinity and has optimal activity at 600 mM Na+. Homologues are found in Pseudomonadota of all groups, '' Flavobacteriia'', and ''Chlamydia.'' Distant homologues of the IT superfamily are ubiquitous. The generalized reaction catalyzed by NhaD is:nH+ (in) + mNa+ (out) ⇌ nH+ (out) + mNa+ (in). See also * Sodium-Proton antiporter * Antiporter * Transporter Classification Data ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escherichia Coli
''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escherichia'' that is commonly found in the lower intestine of warm-blooded organisms. Most ''E. coli'' strains are harmless, but some serotypes ( EPEC, ETEC etc.) can cause serious food poisoning in their hosts, and are occasionally responsible for food contamination incidents that prompt product recalls. Most strains do not cause disease in humans and are part of the normal microbiota of the gut; such strains are harmless or even beneficial to humans (although these strains tend to be less studied than the pathogenic ones). For example, some strains of ''E. coli'' benefit their hosts by producing vitamin K2 or by preventing the colonization of the intestine by pathogenic bacteria. These mutually beneficial relationships between ''E. col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuole
A vacuole () is a membrane-bound organelle which is present in plant and fungal cells and some protist, animal, and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain cases they may contain solids which have been engulfed. Vacuoles are formed by the fusion of multiple membrane vesicles and are effectively just larger forms of these. The organelle has no basic shape or size; its structure varies according to the requirements of the cell. Discovery Contractile vacuoles ("stars") were first observed by Spallanzani (1776) in protozoa, although mistaken for respiratory organs. Dujardin (1841) named these "stars" as ''vacuoles''. In 1842, Schleiden applied the term for plant cells, to distinguish the structure with cell sap from the rest of the protoplasm. In 1885, de Vries named the vacuole membrane as tonoplast. Function The function and signifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The main components of the cytoplasm are cytosol (a gel-like substance), the organelles (the cell's internal sub-structures), and various cytoplasmic inclusions. The cytoplasm is about 80% water and is usually colorless. The submicroscopic ground cell substance or cytoplasmic matrix which remains after exclusion of the cell organelles and particles is groundplasm. It is the hyaloplasm of light microscopy, a highly complex, polyphasic system in which all resolvable cytoplasmic elements are suspended, including the larger organelles such as the ribosomes, mitochondria, the plant plastids, lipid droplets, and vacuoles. Most cellular activities take place within the cytoplasm, such as many metabolic pathways including glycolysis, and proces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
