How Do Neurons Communicate?
... receive chemical messages. Micrographs also reveal some dark patches on the presynaptic membrane, the membrane of the axon terminal, although these patches are harder to see. Here, too, the patches are protein molecules, which in this case serve largely as channels and pumps, as well as receptor sit ...
... receive chemical messages. Micrographs also reveal some dark patches on the presynaptic membrane, the membrane of the axon terminal, although these patches are harder to see. Here, too, the patches are protein molecules, which in this case serve largely as channels and pumps, as well as receptor sit ...
Kv2 Channels Form Delayed-Rectifier Potassium Channels In Situ
... immature and mature times did not vary (40 and 36%, respectively), the inferred proportions of Kv2 channels are similar. The mutant subunit may have produced this effect by decreasing either the number of functional channels, the single-channel conductance, or Popen. These results suggest that funct ...
... immature and mature times did not vary (40 and 36%, respectively), the inferred proportions of Kv2 channels are similar. The mutant subunit may have produced this effect by decreasing either the number of functional channels, the single-channel conductance, or Popen. These results suggest that funct ...
Module 3: Defects, Diffusion and Conduction in Ceramics
... driving force for diffusion. Thermodynamically speaking, this amounts to gradient in the chemical potential which drives the migration of species from regions of higher chemical potential to lower chemical potential so that system reaches a chemical equilibrium. The atomic flux as a result of drivin ...
... driving force for diffusion. Thermodynamically speaking, this amounts to gradient in the chemical potential which drives the migration of species from regions of higher chemical potential to lower chemical potential so that system reaches a chemical equilibrium. The atomic flux as a result of drivin ...
Distribution of lens sodium-potassium-adenosine
... contains sodium-potassium-adenosine triphosphatase (Na-K-ATPase), and that this sodium pump mechanism is responsible for maintaining the electrolyte balance in the organ.2'3 Initially, Bonting and his coworkers2'3 and Palva and Palkama4 reported that the Na-K-ATPase activity is localized almost enti ...
... contains sodium-potassium-adenosine triphosphatase (Na-K-ATPase), and that this sodium pump mechanism is responsible for maintaining the electrolyte balance in the organ.2'3 Initially, Bonting and his coworkers2'3 and Palva and Palkama4 reported that the Na-K-ATPase activity is localized almost enti ...
9 Propagated Signaling: The Action Potential
... Propagated Signaling: The Action Potential John Koester Steven A. Siegelbaum NERVE CELLS ARE ABLE TO carry signals over long distances because of their ability to generate an action potential—a regenerative electrical signal whose amplitude does not attenuate as it moves down the axon. In Chapter 7 ...
... Propagated Signaling: The Action Potential John Koester Steven A. Siegelbaum NERVE CELLS ARE ABLE TO carry signals over long distances because of their ability to generate an action potential—a regenerative electrical signal whose amplitude does not attenuate as it moves down the axon. In Chapter 7 ...
Biogenesis and origin of thylakoid membranes
... prolonged extensions into the stroma. Thus, the arrangement of the thylakoid membrane system creates a single huge compartment inside the chloroplast, the thylakoid lumen. Additionally to creating a single internal space this structure builds a membrane surface that is much larger than a simple inva ...
... prolonged extensions into the stroma. Thus, the arrangement of the thylakoid membrane system creates a single huge compartment inside the chloroplast, the thylakoid lumen. Additionally to creating a single internal space this structure builds a membrane surface that is much larger than a simple inva ...
Pacemaker Potentials for the Periodic Burst Discharge in the Heart
... the preceding paper (Watanabe, Obara, Akiyama, and Yumoto, 1967). The method of recording is also similar to that in the preceding paper. Various authors disagree on the location of the pacemaker in the Squilla heart ganglion. Irisawa and Irisawa (1957) state, based on transection experiments, that ...
... the preceding paper (Watanabe, Obara, Akiyama, and Yumoto, 1967). The method of recording is also similar to that in the preceding paper. Various authors disagree on the location of the pacemaker in the Squilla heart ganglion. Irisawa and Irisawa (1957) state, based on transection experiments, that ...
Theoretical studies of Membrane Proteins
... to all membrane proteins? What is the overall architecture of a membrane protein? What properties govern the integration into the membrane? How many membrane proteins are there and how are they distributed in different organisms? Several of the findings have now been backed up by experiments. An ana ...
... to all membrane proteins? What is the overall architecture of a membrane protein? What properties govern the integration into the membrane? How many membrane proteins are there and how are they distributed in different organisms? Several of the findings have now been backed up by experiments. An ana ...
Cell-penetrating peptides and antimicrobial peptides: how different
... the pore may not be the principal process of translocation; instead, it has been proposed that it is the peptide molecules that are involved in pore formation that stochastically translocate as the pore disintegrates [28]. Several factors support this statement, the most relevant being the fact that ...
... the pore may not be the principal process of translocation; instead, it has been proposed that it is the peptide molecules that are involved in pore formation that stochastically translocate as the pore disintegrates [28]. Several factors support this statement, the most relevant being the fact that ...
biochemical, biophysical and electrophysiological characterisation
... The eukaryotic voltage-gated sodium channel Na v is an integral membrane protein that transports sodium across the cell membrane. While the Na v has a four-domain structure with six α-helical transmembrane segments in each domain, the first bacterial homologue, which was identified in 2001 in Bacill ...
... The eukaryotic voltage-gated sodium channel Na v is an integral membrane protein that transports sodium across the cell membrane. While the Na v has a four-domain structure with six α-helical transmembrane segments in each domain, the first bacterial homologue, which was identified in 2001 in Bacill ...
Degradation by bacteria of membrane and soluble protein in seawater
... Aquat Microb Ecol 1 4 : 29-37, 1998 ...
... Aquat Microb Ecol 1 4 : 29-37, 1998 ...
Connection of the Mitochondrial Outer and Inner Membranes by
... 1996). Viral fusion proteins, such as hemagglutinin, are integral proteins of viral membranes. Upon activation, a hydrophobic fusion peptide inserts into the target membrane. An extensive rearrangement of the molecule leads to the formation of an antiparallel coiled coil structure, again with both m ...
... 1996). Viral fusion proteins, such as hemagglutinin, are integral proteins of viral membranes. Upon activation, a hydrophobic fusion peptide inserts into the target membrane. An extensive rearrangement of the molecule leads to the formation of an antiparallel coiled coil structure, again with both m ...
Near-UV-induced absorbance change and
... pressure. The flow rate of gases was 70 ml min-l. Absorbance changes in cell suspensions exposed to near-UV at various dosages were measured with an automatic spectrophotometer (Shimadzu UV-3000). In order to detect slight changes of absorption spectra, difference spectra were calculated by subtract ...
... pressure. The flow rate of gases was 70 ml min-l. Absorbance changes in cell suspensions exposed to near-UV at various dosages were measured with an automatic spectrophotometer (Shimadzu UV-3000). In order to detect slight changes of absorption spectra, difference spectra were calculated by subtract ...
IOSR Journal of Applied Chemistry (IOSR-JAC)
... planktonic Acidithiobacillus ferrooxidans bacteria had different PLs profile then sessile bacterial. Biofilm formation by Acidithiobacillus ferrooxidans may be regulated by new PLs present in the cell membrane. The industrial processes, Biofilm formation, biofouling and attachment related mechanisms ...
... planktonic Acidithiobacillus ferrooxidans bacteria had different PLs profile then sessile bacterial. Biofilm formation by Acidithiobacillus ferrooxidans may be regulated by new PLs present in the cell membrane. The industrial processes, Biofilm formation, biofouling and attachment related mechanisms ...
Mechanisms Shaping the Membranes of Cellular Organelles
... mid surface [bilayer-coupling mechanism (Sheetz & Singer 1974)]. In agreement with these predictions, it has been found experimentally that high mole fractions of some lipids can ...
... mid surface [bilayer-coupling mechanism (Sheetz & Singer 1974)]. In agreement with these predictions, it has been found experimentally that high mole fractions of some lipids can ...
Force development by the contractile vacuole
... and the mineral oil, the CV rounded against this force during its rounding phase. It can, therefore, be supposed that the tension at the surface of the CV increases during the rounding phase. We previously proposed a hypothesis (Tominaga et al., 1998a; Tominaga et al., 1999) that an increase in the ...
... and the mineral oil, the CV rounded against this force during its rounding phase. It can, therefore, be supposed that the tension at the surface of the CV increases during the rounding phase. We previously proposed a hypothesis (Tominaga et al., 1998a; Tominaga et al., 1999) that an increase in the ...
Membrane potential
Membrane potential (also transmembrane potential or membrane voltage) is the difference in electric potential between the interior and the exterior of a biological cell. With respect to the exterior of the cell, typical values of membrane potential range from –40 mV to –80 mV.All animal cells are surrounded by a membrane composed of a lipid bilayer with proteins embedded in it. The membrane serves as both an insulator and a diffusion barrier to the movement of ions. Ion transporter/pump proteins actively push ions across the membrane and establish concentration gradients across the membrane, and ion channels allow ions to move across the membrane down those concentration gradients. Ion pumps and ion channels are electrically equivalent to a set of batteries and resistors inserted in the membrane, and therefore create a voltage difference between the two sides of the membrane.Virtually all eukaryotic cells (including cells from animals, plants, and fungi) maintain a non-zero transmembrane potential, usually with a negative voltage in the cell interior as compared to the cell exterior ranging from –40 mV to –80 mV. The membrane potential has two basic functions. First, it allows a cell to function as a battery, providing power to operate a variety of ""molecular devices"" embedded in the membrane. Second, in electrically excitable cells such as neurons and muscle cells, it is used for transmitting signals between different parts of a cell. Signals are generated by opening or closing of ion channels at one point in the membrane, producing a local change in the membrane potential. This change in the electric field can be quickly affected by either adjacent or more distant ion channels in the membrane. Those ion channels can then open or close as a result of the potential change, reproducing the signal.In non-excitable cells, and in excitable cells in their baseline states, the membrane potential is held at a relatively stable value, called the resting potential. For neurons, typical values of the resting potential range from –70 to –80 millivolts; that is, the interior of a cell has a negative baseline voltage of a bit less than one-tenth of a volt. The opening and closing of ion channels can induce a departure from the resting potential. This is called a depolarization if the interior voltage becomes less negative (say from –70 mV to –60 mV), or a hyperpolarization if the interior voltage becomes more negative (say from –70 mV to –80 mV). In excitable cells, a sufficiently large depolarization can evoke an action potential, in which the membrane potential changes rapidly and significantly for a short time (on the order of 1 to 100 milliseconds), often reversing its polarity. Action potentials are generated by the activation of certain voltage-gated ion channels.In neurons, the factors that influence the membrane potential are diverse. They include numerous types of ion channels, some of which are chemically gated and some of which are voltage-gated. Because voltage-gated ion channels are controlled by the membrane potential, while the membrane potential itself is influenced by these same ion channels, feedback loops that allow for complex temporal dynamics arise, including oscillations and regenerative events such as action potentials.