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  • investigate
  • Investigating the effect of temperature on cell membrane permeability To investigate the effect of temperature on cell membrane permeability, I am going to use beetroot due to its pigment properties. (markedbyteachers.com)
  • The property of solutions of Triton X-114 to separate into detergent-rich and detergent-poor phases at 30 degrees C has been exploited to investigate the identities of the aminopeptidases in synaptic membrane preparations from pig striatum. (biochemj.org)
  • fluid
  • The general approach of the solution-diffusion model is to assume that the chemical potential of the feed and permeate fluids are in equilibrium with the adjacent membrane surfaces such that appropriate expressions for the chemical potential in the fluid and membrane phases can be equated at the solution-membrane interface. (wikipedia.org)
  • The paucimolecular model immediately became popular and it dominated cell membrane studies for the following 30 years, until it became rivaled by the fluid mosaic model of Singer and Nicolson (1972). (wikipedia.org)
  • Despite the numerous models of the cell membrane proposed prior to the fluid mosaic model , it remains the primary archetype for the cell membrane long after its inception in the 1970s. (wikipedia.org)
  • Although the fluid mosaic model has been modernized to detail contemporary discoveries, the basics have remained constant: the membrane is a lipid bilayer composed of hydrophilic exterior heads and a hydrophobic interior where proteins can interact with hydrophilic heads through polar interactions, but proteins that span the bilayer fully or partially have hydrophobic amino acids that interact with the non-polar lipid interior. (wikipedia.org)
  • Of the numerous models that have been developed to describe the deformation of cell membranes, a widely accepted model is the fluid mosaic model proposed by Singer and Nicolson in 1972. (wikipedia.org)
  • In this model, the cell membrane surface is modeled as a two-dimensional fluid-like lipid bilayer where the lipid molecules can move freely. (wikipedia.org)
  • With the amnihook method, a sterile plastic hook is inserted into the vagina and used to puncture the membranes containing the amniotic fluid. (wikipedia.org)
  • With the membranes punctured, amniotic fluid is able to escape from the uterus and exit the vagina. (wikipedia.org)
  • The sac (consisting of 2 membranes, the chorion and amnion) contains amniotic fluid, which surrounds and protects the fetus in the uterus (womb). (wikipedia.org)
  • In anatomy, serous membrane (or serosa) is a smooth tissue membrane consisting of two layers of mesothelium, which secrete serous fluid. (wikipedia.org)
  • Between the two layers is a potential space, mostly empty except for a few milliliters of lubricating serous fluid that is secreted by the two serous membranes. (wikipedia.org)
  • Serous membranes line and enclose several body cavities, known as serous cavities, where they secrete a lubricating fluid which reduces friction from muscle movement. (wikipedia.org)
  • The serous fluid produced by the serous membranes reduces friction between the walls of the cavities and the internal organs when they move, such as when the lungs inflate or the heart beats, that could otherwise lead to inflammation of the organs. (wikipedia.org)
  • The serous membranes have two layers, parietal and visceral, surrounding a fluid filled space. (wikipedia.org)
  • The fluid mosaic model not only provided an accurate representation of membrane mechanics, it enhanced the study of hydrophobic forces, which would later develop into an essential descriptive limitation to describe biological macromolecules. (wikipedia.org)
  • gradients
  • The latter can be facilitated by pressure, concentration, chemical or electrical gradients of the membrane process. (wikipedia.org)
  • A number of enzymes are membrane bound and often mass transport through the membrane is active rather than passive as in artificial membranes allowing the cell to keep up gradients for example by using active transport of protons or water. (wikipedia.org)
  • collagen
  • The Jason® membrane is a native collagen membrane obtained from porcine pericardium, developed and manufactured for dental tissue regeneration. (straumann.com)
  • Due to its natural comb-like and multi-layered collagen structure (with an increased content of collagen type III), the botiss Jason® membrane shows a slow degradation, making it the recommended choice in our portfolio particularly for large augmentative procedures. (straumann.com)
  • A native collagen membrane. (straumann.com)
  • The collprotect® membrane is a native collagen membrane made of porcine dermis. (straumann.com)
  • The unique processing, as well as the open porous/3-dimensional collagen structure of this membrane, are the basis for its application in dental bone and tissue regeneration. (straumann.com)
  • Poor assembly of collagen: collagen is a molecule that gives fetal membranes their strength. (wikipedia.org)
  • The electron-dense lamina densa membrane is about 30-70 nanometers thick, and consists of an underlying network of reticular collagen IV fibrils which average 30 nanometers in diameter and 0.1-2 micrometers in thickness. (wikipedia.org)
  • Genetic defects in the collagen fibers of the basement membrane cause Alport syndrome and Knobloch syndrome. (wikipedia.org)
  • Non-collagenous domain basement membrane collagen type IV is autoantigen (target antigen) of autoantibodies in the autoimmune disease Goodpasture's syndrome. (wikipedia.org)
  • molecules
  • Although some lipid-soluble molecules can permeate the cell membrane, many of the nutrients that a cell needs to function are too large to readily enter the cell. (encyclopedia.com)
  • Examples of transporters are channels, which facilitate free movement of molecules across the membranes, and pumps, which require a certain amount of energy in order to transport molecules. (encyclopedia.com)
  • While lipid-soluble molecules can pass readily through the membrane, water-soluble and larger particles require another mode of entry. (encyclopedia.com)
  • Only lipid-soluble molecules and some small particles (e.g., biologically important gases such as oxygen and nitrogen) can readily permeate the cell membrane. (encyclopedia.com)
  • Passive transport or facilitated diffusion occurs when water-soluble molecules and ions move through the membrane with the help of transporters (also called permeases). (encyclopedia.com)
  • This concentration gradient is created by molecules which cannot pass through the membrane. (wikipedia.org)
  • During this process the retained particles or molecules form a pulpy mass ( filter cake ) on the membrane, and this blockage of the membrane hampers the filtration. (wikipedia.org)
  • Movement of molecules through membranes is a primary means of sending signals to and from cells. (ucsd.edu)
  • permeability
  • It wasn't until later studies with osmosis and permeability that cell membranes gained more recognition. (wikipedia.org)
  • Barrier membranes designed for GBR/GTR have to meet the following criteria: host tissue integration, biocompatibility, cell occlusiveness, permeability for nutrients and ease of use 1 . (straumann.com)
  • selectivity
  • The selectivity of the membranes is due to Donnan equilibrium and Donnan exclusion and not due to physically blocking or electrostatically excluding specific charged species. (wikipedia.org)
  • The permselectivity of ion-exchange membranes describes their charge selectivity. (wikipedia.org)
  • A higher selectivity leads to increased recovery and performance of the membrane. (wikipedia.org)
  • However, due to the lack of reliability, slow operation, reduced selectivity and elevated costs, membranes were not widely exploited. (wikipedia.org)
  • The degree of selectivity of a membrane depends on the membrane pore size. (wikipedia.org)
  • The selectivity of the transport through the membrane is dependent by the difference in solubility of the materials in the membrane and their diffusivity through the membrane. (wikipedia.org)
  • protein
  • The distinct behavior of ribosomes synthesizing the inner envelope protein CemA indicates that sorting signals for the thylakoid and envelope membranes are distinguished cotranslationally. (pnas.org)
  • The chloroplast thylakoid membrane is a highly organized, protein-rich, and dynamic membrane system that is the site of the light reactions of photosynthesis ( 1 ). (pnas.org)
  • A common companion for blotting paper is nitrocellulose membranes, often used for protein and DNA analysis and purifications. (sartorius.com)
  • 200 μg/cm2) Sartorius' nitrocellulose membranes are ideal for western blotting, DNA blotting as well as dot or slot blots, and they have been optimized for superior performance in all protein blotting systems, including electrotransfer, semi-dry or simple capillary blotting applications. (sartorius.com)
  • Polyethersulfone (PES) membrane filters are hydrophilic, high flow rate and low non-specific protein adsorptive membranes. (sartorius.com)
  • In addition, cell membranes are involved in a variety of cellular processes such as cell adhesion , ion conductivity and cell signalling and serve as the attachment surface for several extracellular structures, including the cell wall , the carbohydrate layer called the glycocalyx , and the intracellular network of protein fibers called the cytoskeleton . (wikipedia.org)
  • OPM also provides structural classification of membrane-associated proteins into families and superfamilies, membrane topology , quaternary structure of proteins in membrane-bound state, and the type of a destination membrane for each protein. (wikipedia.org)
  • The site allows visualization of protein structures with membrane boundary planes through Jmol . (wikipedia.org)
  • The concept of lateral movement (lateral diffusion) of transmembrane protein complexes can be shown by having students insert a pencil or other object through the membrane and move it around. (accessexcellence.org)
  • This mimics the membrane-protein-catalyzed assembly of phospholipids in live cells, which also uses long-chain thioesters as precursors. (ucsd.edu)
  • Compared to other classes of proteins, the determination of membrane protein structures has remained a challenge in large part due to the difficulty in establishing experimental conditions where the correct conformation of the protein in isolation from its native environment is preserved. (wikipedia.org)
  • filtration
  • In real membranes, these two transport mechanisms certainly occur side by side, especially during ultra-filtration. (wikipedia.org)
  • During the filtration process a boundary layer forms on the membrane. (wikipedia.org)
  • The effect is referred as concentration polarization and, occurring during the filtration, leads to a reduced trans-membrane flow ( flux ). (wikipedia.org)
  • Using a tangential flow to the membrane (cross-flow filtration) can also minimize concentration polarization. (wikipedia.org)
  • The first use of membranes on a large scale was with micro-filtration and ultra-filtration technologies. (wikipedia.org)
  • As of 2017 many other roles for basement membrane have been found that include blood filtration and muscle homeostasis. (wikipedia.org)
  • The membrane can be used for different tasks: Separation Selective extraction of reactants Retention of the catalyst Distribution/dosing of a reactant Catalyst support (often combined with distribution of reactants) Membrane reactors are an example for the combination of two unit operations in one step e.g. membrane filtration with the chemical reaction. (wikipedia.org)
  • Submerged and sidestream membrane bioreactors in wastewater treatment plants are the most developed filtration based membrane reactors. (wikipedia.org)
  • type of membrane
  • Depending on the type of membrane, the selective separation of certain individual substances or substance mixtures is possible. (wikipedia.org)
  • Synthetic Rubber (Thermoset) - This type of membrane roof is made of large, flat pieces of synthetic rubber or similar materials. (wikipedia.org)
  • outer
  • Mitochondrial outer membrane permeabilization (MOMP), is a reason of the higher matrix Ca2 + levels, which is acts as a trigger for apoptosis. (wikipedia.org)
  • degradation
  • Our membranes exhibit outstanding handling properties, controlled degradation patterns and are characterized by their excellent biocompatibility, making them the ideal choice for applications in implant dentistry and periodontology. (straumann.com)
  • The main function of these membrane is degradation, as role in cellular homeostasis. (wikipedia.org)
  • structures
  • In 1890, an update to the Cell Theory stated that cell membranes existed, but were merely secondary structures. (wikipedia.org)
  • This is the case when all membrane-anchoring parts of the proteins ( amphiphilic alpha helices , exposed nonpolar residues, or lipidated amino acid residues ) are missing in the experimental structures. (wikipedia.org)
  • The connective tissue layer provides the blood vessels and nerves for the overlying secretory cells, and also serves as the binding layer which allows the whole serous membrane to adhere to organs and other structures. (wikipedia.org)
  • permeate
  • In the membrane field, the term module is used to describe a complete unit composed of the membranes, the pressure support structure, the feed inlet, the outlet permeate and retentate streams, and an overall support structure. (wikipedia.org)
  • Spiral Wound, where a flexible permeate spacer is placed between two flat membranes sheet. (wikipedia.org)
  • The plate supports the membranes and provides a channel for the permeate to flow out of the unit module. (wikipedia.org)
  • enzymes
  • Natural cells use enzymes to catalyze the biochemical reactions that manufacture their membranes from thioester precursors, but in this case Devaraj's team was able to get membranes to assemble spontaneously, without enzymes, through a process called native chemical ligation. (ucsd.edu)
  • Membrane enzymes may have many activities, such as oxidoreductase, transferase or hydrolase. (wikipedia.org)
  • thickness
  • In an attempt to accept or reject the hypothesis, researchers measured membrane thickness. (wikipedia.org)
  • The present invention relates to a membrane comprising at least one molecular monolayer composed of low-molecular aromatics and cross-linked in the lateral direction, wherein the membrane has a thickness in the range from 1 to 200 nm and a perforation in the form of openings having a diameter in the range from 0.1 nm to 1 μm, to a method for the production thereof, and to a use thereof. (freepatentsonline.com)
  • Due to these unique properties, the Jason® membrane exhibits beneficial handling characteristics such as distinct tear resistance, despite its low thickness of only 0.1 to 0.25 mm, and easy drapery and adaptation to the bone surface. (straumann.com)
  • occurs
  • The transition from soluble to membrane-attached ribosomes occurs shortly after the first transmembrane segment in the nascent peptide has emerged from the ribosome. (pnas.org)
  • Permeation occurs when a substance moves through the membrane from a region of high concentration to a region of low concentration, a process called diffusion. (encyclopedia.com)
  • mechanical
  • In general, mechanical separation processes for separating gaseous or liquid streams use membrane technology. (wikipedia.org)
  • The basement membrane acts as a mechanical barrier, preventing malignant cells from invading the deeper tissues. (wikipedia.org)
  • Due to the increased structural complexity of the TM relative to other acellular gels (such as the otolithic membranes), its mechanical properties are consequently significantly more complex. (wikipedia.org)
  • The mechanical role of the tectorial membrane in hearing is yet to be fully understood, and traditionally was neglected or downplayed in many models of the cochlea. (wikipedia.org)
  • enclose
  • Neal Devaraj, a chemistry and biochemistry professor at UC San Diego, leads a research team that develops and explores new reactions that can trigger the formation of membranes, particularly the spheres that characterize membranes that enclose vesicles and cells. (ucsd.edu)
  • particles
  • Membrane emulsification (ME) is a relatively novel technique for producing all types of single and multiple emulsions for DDS (drug delivery systems), solid micro carriers for encapsulation of drug or nutrient, solder particles for surface-mount technology, mono dispersed polymer microspheres (for analytical column packing, enzyme carriers, liquid crystal display spacers, toner core particles). (wikipedia.org)
  • Chemically
  • These membranes are unique in that they can be manipulated chemically and their electrical properties can be studied by application of biophysical techniques. (wikipedia.org)
  • bacteria
  • minimize particulate and microbial fouling of the RO membranes by removal of turbidity and bacteria, (2) prevent scaling by removal of the hardness ions, (3) lower the operating pressure of the RO process by reducing the feed-water total dissolved solids (TDS) concentration. (wikipedia.org)
  • tissue
  • The thin membrane facilitates soft tissue manipulation, particularly in challenging thin biotypes. (straumann.com)
  • The basement membrane is a thin, fibrous, extracellular matrix of tissue that separates the lining of an internal or external body surface from underlying connective tissue in metazoans. (wikipedia.org)
  • As seen with electron microscope, the basement membrane is composed of two layers, the basal lamina and the underlying layer of reticular connective tissue. (wikipedia.org)
  • Conductive
  • The project, "Highly Conductive, Stable and Robust Hydroxide Exchange Membranes Based on Poly (Aryl Piperidinium)," is one of 16 funded through the $37 million program, which is aimed at transforming energy storage and conversion. (udel.edu)
  • Ion-exchange membranes transport dissolved ions across a conductive polymeric membrane. (wikipedia.org)
  • localization
  • However, the targeting of nucleus-encoded proteins to the thylakoid membrane is posttranslational, as they are synthesized in the cytosol and then imported into the chloroplast stroma before their membrane localization. (pnas.org)
  • The membrane localization has been confirmed for more than 600 of them experimentally. (wikipedia.org)
  • describes
  • Mobile membranes represents a formalism which describes the movement of membranes inside a spatial structure by applying rules from a given set of rules R {\displaystyle R} . The mobility is provided by consumption and rewriting of objects. (wikipedia.org)
  • synthetic
  • Synthetic membranes are made by humans for use in laboratories and industry (such as chemical plants). (wikipedia.org)
  • Membrane roofs are most commonly made from synthetic rubber, thermoplastic (PVC or similar material), or modified bitumen. (wikipedia.org)
  • Thermoplastic Membrane - This is similar to synthetic rubber, but the seams are typically heat-fused (welded) to form a continuous membrane. (wikipedia.org)
  • separation
  • Membrane separation processes operate without heating and therefore use less energy than conventional thermal separation processes such as distillation , sublimation or crystallization . (wikipedia.org)
  • Furthermore, using membranes enables separations to take place that would be impossible using thermal separation methods. (wikipedia.org)
  • Membrane Science and Technology Series, 9: Ion Exchange Membrane Separation Processes (First ed. (wikipedia.org)
  • A membrane reactor is a physical device that combines a chemical conversion process with a membrane separation process to add reactants or remove products of the reaction. (wikipedia.org)