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Antiporter Alone
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. Sodium-proton antiporter, 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 Adenosine triphosphate, ATP. Transport may involve one or more of each type of solute. For example, the Sodium-calcium exchanger, 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 Mechani ... [...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] |
Prokaryote
A prokaryote () is a single-celled organism that lacks a nucleus and other membrane-bound organelles. The word ''prokaryote'' comes from the Greek πρό (, 'before') and κάρυον (, 'nut' or 'kernel').Campbell, N. "Biology:Concepts & Connections". Pearson Education. San Francisco: 2003. In the two-empire system arising from the work of Édouard Chatton, prokaryotes were classified within the empire Prokaryota. But in the three-domain system, based upon molecular analysis, prokaryotes are divided into two domains: ''Bacteria'' (formerly Eubacteria) and ''Archaea'' (formerly Archaebacteria). Organisms with nuclei are placed in a third domain, Eukaryota. In the study of the origins of life, prokaryotes are thought to have arisen before eukaryotes. Besides the absence of a nucleus, prokaryotes also lack mitochondria, or most of the other membrane-bound organelles that characterize the eukaryotic cell. It was once thought that prokaryotic cellular components within the cytop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proceedings Of The National Academy Of Sciences Of The United States Of America
''Proceedings of the National Academy of Sciences of the United States of America'' (often abbreviated ''PNAS'' or ''PNAS USA'') is a peer-reviewed multidisciplinary scientific journal. It is the official journal of the National Academy of Sciences, published since 1915, and publishes original research, scientific reviews, commentaries, and letters. According to ''Journal Citation Reports'', the journal has a 2021 impact factor of 12.779. ''PNAS'' is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the mass media, ''PNAS'' has been described variously as "prestigious", "sedate", "renowned" and "high impact". ''PNAS'' is a delayed open access journal, with an embargo period of six months that can be bypassed for an author fee ( hybrid open access). Since September 2017, open access articles are published under a Creative Commons license. Since January 2019, ''PNAS'' has been online-only, although print issues are ava ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Facilitated Diffusion
Facilitated diffusion (also known as facilitated transport or passive-mediated transport) is the process of spontaneous passive transport (as opposed to active transport) of molecules or ions across a biological membrane via specific transmembrane integral proteins. Being passive, facilitated transport does not directly require chemical energy from ATP hydrolysis in the transport step itself; rather, molecules and ions move down their concentration gradient reflecting its diffusive nature. Facilitated diffusion differs from simple diffusion in several ways. # the transport relies on molecular binding between the cargo and the membrane-embedded channel or carrier protein. # the rate of facilitated diffusion is saturable with respect to the concentration difference between the two phases; unlike free diffusion which is linear in the concentration difference. # the temperature dependence of facilitated transport is substantially different due to the presence of an activated bin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symporter
A symporter is an integral membrane protein that is involved in the transport of two (or more) different molecules across the cell membrane in the same direction. The symporter works in the plasma membrane and molecules are transported across the cell membrane at the same time, and is, therefore, a type of cotransporter. The transporter is called a symporter, because the molecules will travel in the same direction in relation to each other. This is in contrast to the antiport transporter. Typically, the ion(s) will move down the electrochemical gradient, allowing the other molecule(s) to move against the concentration gradient. The movement of the ion(s) across the membrane is facilitated diffusion, and is coupled with the active transport of the molecule(s). In symport, two molecule move in 'similar direction' at the 'same time' Example of symport:- movement of glucose along with sodium ion Examples SGLT1 in the intestinal epithelium transports sodium ions (Na+) and glucose acro ... [...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] |
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] |
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] |
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] |
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] |
