• hydrophobic
  • 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)
  • Their theory was also incorrect in that it ascribed the barrier properties of the membrane to electrostatic repulsion from the protein layer rather than the energetic cost of crossing the hydrophobic core. (wikipedia.org)
  • aqueous
  • Alkaline anion exchange membrane fuel cells (AAEMFCs) are functionally similar to AFCs, the difference being AAEMFCs employ a solid polymer electrolyte while AFCs use aqueous potassium hydroxide (KOH) as an electrolyte. (wikipedia.org)
  • Electrochemical reactions when hydrogen is the fuel At Anode: H2 + 2OH− → 2H2O + 2e− At cathode: O2 + 2H2O + 4e− → 4OH− Electrochemical reactions when methanol is the fuel At anode: CH3OH + 6OH− → CO2 + 5H2O + 6e- At cathode: 3/2O2 + 3H2O + 6e− → 6OH− The alkaline fuel cell used by NASA in 1960s for Apollo and Space Shuttle program generated electricity at nearly 70% efficiency using aqueous solution of KOH as an electrolyte. (wikipedia.org)
  • transporters
  • The structure and function of the red cell membrane and associated ion transporters play an important role in the pathology of red cell genetic defects. (els.net)
  • Diagram of transporters present in the human red cell membrane. (els.net)
  • Drew C, Ball V, Robinson H, Clive Ellory J and Gibson JS (2004) Oxygen sensitivity of red cell membrane transporters revisited. (els.net)
  • Electron
  • Firstly, the role of multi-domain cell surface proteins involved in cell recognition and secondly, the components of the electron-transport chain and its relation to energy transduction including an introduction to Mitchell's chemi-osmotic hypothesis. (southampton.ac.uk)
  • A more direct investigation of the membrane was made possible through the use of electron microscopy in the late 1950s. (wikipedia.org)
  • vesicles
  • 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)
  • Self-assembled vesicles are essential components of primitive cells. (wikipedia.org)
  • receptors
  • These receptors are increased in number on luminal side by fusion of tubulovesicles during activation of parietal cells and removed during deactivation. (wikipedia.org)
  • Parietal cells secrete acid in response to three types of stimuli: Histamine, stimulates H2 histamine receptors (most significant contribution). (wikipedia.org)
  • These receptors are present on basolateral side of membrane. (wikipedia.org)
  • fluid
  • 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)
  • Traube had no direct evidence for the composition of this film, though, and incorrectly asserted that it was formed by an interfacial reaction of the cell protoplasm with the extracellular fluid. (wikipedia.org)
  • Based on these observations, Quincke asserted that the cell membrane comprised a fluid layer of fat less than 100 nm thick. (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)
  • protons
  • This oxidation half-cell reaction or hydrogen oxidation reaction (HOR) is represented by: At the anode: The newly formed protons permeate through the polymer electrolyte membrane to the cathode side. (wikipedia.org)
  • This reduction half-cell reaction or oxygen reduction reaction (ORR) is represented by: At the cathode: Overall reaction: The reversible reaction is expressed in the equation and shows the reincorporation of the hydrogen protons and electrons together with the oxygen molecule and the formation of one water molecule. (wikipedia.org)
  • They drive the hyperpolarization of the cell membrane by secreting protons in presence of light. (wikipedia.org)
  • As the pH naturally neutralizes within the liposome (protons can pass through some membranes), the drug will also be neutralized, allowing it to freely pass through a membrane. (wikipedia.org)
  • cathode
  • The electrons travel along an external load circuit to the cathode side of the MEA, thus creating the current output of the fuel cell. (wikipedia.org)
  • Finally, the membrane must be resistant to the reducing environment at the cathode as well as the harsh oxidative environment at the anode. (wikipedia.org)
  • Water management is a very difficult subject in PEM systems, primarily because water in the membrane is attracted toward the cathode of the cell through polarization. (wikipedia.org)
  • Also, methanol crossover from anode to cathode is reduced in AAEMFCs compared to PEMFCs, due to the opposite direction of ion transport in the membrane, from cathode to anode. (wikipedia.org)
  • Biology
  • In the field of synthetic biology, cell membranes can be artificially reassembled. (wikipedia.org)
  • This course covers molecular biology of prokaryotic and eukaryotic cells and their viruses. (nottingham.ac.uk)
  • This is an introductory survey of cell and developmental biology. (nottingham.ac.uk)
  • It has long been the goal of experimental biology and medicine to induce cells to behave in predictable ways and to alter the behavior of cells in ways that are beneficial to a subject. (google.com)
  • Electrokinesis has also been observed in biology, where it was found to cause physical damage to neurons by inciting movement in their membranes. (wikipedia.org)
  • polymer
  • Our goal is to develop a process to easily synthesize the polymer at scale, creating large area membranes for testing that are thinner than human hair. (udel.edu)
  • processes
  • Transport across the cell membrane underlies a variety of physiological processes, from the beating of an animal's heart to the opening of tiny pores in leaves that enables gas exchange with the environment. (newworldencyclopedia.org)
  • A reasonable number of unmyelinated axons remained, although the presence of stacks of flattened Schwann cell processes suggested unmyelinated axon loss. (wikipedia.org)
  • 1991
  • Boman HG (1991), "Antibacterial peptides: key components needed in immunity", Cell, 65 (2): 205-207, doi:10.1016/0092-8674(91)90154-Q, PMID 2015623. (wikipedia.org)
  • erythrocyte
  • Brugnara C (2003) Sickle cell disease: from membrane pathophysiology to novel therapies for prevention of erythrocyte dehydration. (els.net)
  • 1987) Modulation of erythrocyte membrane mechanical stability by 2,3‐diphosphoglycerate in the neonatal poikilocytosis/elliptocytosis syndrome. (els.net)
  • By measuring the capacitance of erythrocyte solutions Fricke determined that the cell membrane was 3.3 nm thick. (wikipedia.org)
  • hydrogen
  • He and colleagues recently reported a breakthrough that promises to bring down the cost of hydrogen fuel cells by replacing expensive platinum catalysts with cheaper ones made from metals like nickel. (udel.edu)
  • The enzyme hydrogen potassium ATPase (H+/K+ ATPase) is unique to the parietal cells and transports the H+ against a concentration gradient of about 3 million to 1, which is the steepest ion gradient formed in the human body. (wikipedia.org)
  • Fricke
  • Although the results of this experiment were accurate, Fricke misinterpreted the data to mean that the cell membrane is a single molecular layer. (wikipedia.org)
  • separates
  • Cell theory has its origins in seventeenth century microscopy observations, but it would be nearly two hundred years before a complete cell membrane theory be developed to explain what separates cells from the outside world. (wikipedia.org)
  • skeleton
  • These results identify the Rh/RhAG-ankyrin complex as a new interaction site between the red cell membrane and the spectrin‐based skeleton, the disruption of which might result in the stomato‐spherocytosis typical of Rh null red cells. (els.net)
  • Thus the free energy density can be expressed as the invariant form of 2 H {\displaystyle 2H} , K {\displaystyle K} , t r ( ε ) {\displaystyle \mathrm {tr} (\varepsilon )} and det ( ε ) {\displaystyle \det(\varepsilon )} : where ε {\displaystyle \varepsilon } is the in-plane strain of the membrane skeleton. (wikipedia.org)
  • Diffusion
  • PEMFCs are built out of membrane electrode assemblies (MEA) which include the electrodes, electrolyte, catalyst, and gas diffusion layers. (wikipedia.org)
  • These liposomes work to deliver drug by diffusion rather than by direct cell fusion. (wikipedia.org)
  • Intrinsic
  • Parietal cells (also known as oxyntic or delomorphous cells), are the epithelial cells that secrete hydrochloric acid (HCl) and intrinsic factor. (wikipedia.org)
  • Parietal cells also produce intrinsic factor. (wikipedia.org)
  • Pernicious anaemia results from autoimmune destruction of gastric parietal cells, precluding the synthesis of intrinsic factor and, by extension, absorption of Vitamin B12. (wikipedia.org)
  • precursors
  • This is accomplished by the fusion of canalicular precursors, or "tubulovesicles", with the membrane to increase surface area, and the reciprocal endocytosis of the canaliculi (reforming the tubulovesicles) to decrease it. (wikipedia.org)