Membrane-active antimicrobial drugs—a reappraisal of their mode
... principles to non-equilibrium situations has been criticized in general terms by some btochemists, but Mitchell's treatment gives rise to numerical data which are supported by experimental findings. In brief, the electrochemical potential of the proton, ~8", is calculated, and is measured as the sum ...
... principles to non-equilibrium situations has been criticized in general terms by some btochemists, but Mitchell's treatment gives rise to numerical data which are supported by experimental findings. In brief, the electrochemical potential of the proton, ~8", is calculated, and is measured as the sum ...
Document
... Use the figure to answer the following questions. 1. The diagrams below represent the six steps in one cycle of the sodium-potassium pump. The order of the steps has been scrambled. Beginning with diagram d (numbered 1), sequence the remaining diagrams by writing the appropriate numeral in each blan ...
... Use the figure to answer the following questions. 1. The diagrams below represent the six steps in one cycle of the sodium-potassium pump. The order of the steps has been scrambled. Beginning with diagram d (numbered 1), sequence the remaining diagrams by writing the appropriate numeral in each blan ...
Passive & Active Transport
... 1. Compare and Contrast Passive What did it mean to have and Active Transport. ACTIVE transport? What – P _____ made it ACTIVE! 2. Explain how a Sodium Potassium pump works. ...
... 1. Compare and Contrast Passive What did it mean to have and Active Transport. ACTIVE transport? What – P _____ made it ACTIVE! 2. Explain how a Sodium Potassium pump works. ...
Understanding Atomic Interactions to Achieve Well-being
... in man, a largely unmet medical need and a fascinating biophysical phenomenon. Channels are inherently capable of opening and closing, allowing or blocking sodium ions from traveling through the pore. In fact, they can do so spontaneously, traversing a variety of different conformational states over ...
... in man, a largely unmet medical need and a fascinating biophysical phenomenon. Channels are inherently capable of opening and closing, allowing or blocking sodium ions from traveling through the pore. In fact, they can do so spontaneously, traversing a variety of different conformational states over ...
RG 5 - Membrane Transport
... 20. What is a gated channel? Distinguish between a ligand-gated and voltage-gated channel. 21. Is there a specific water channel protein? Explain why the discovery of this channel does not discount the generally observation that transport of water is a passive process. 22. Contrast movement by facil ...
... 20. What is a gated channel? Distinguish between a ligand-gated and voltage-gated channel. 21. Is there a specific water channel protein? Explain why the discovery of this channel does not discount the generally observation that transport of water is a passive process. 22. Contrast movement by facil ...
Membrane potential moves toward the K equilibrium
... Resting membrane potential - e.m.f. (voltage) between the inside and outside of a cell: •The zero reference point is outside the cell. •The inside of the cell is negative compared to the ref. •All cells have a membrane potential •In excitable cells (neurons and muscle cells) it is particularly impor ...
... Resting membrane potential - e.m.f. (voltage) between the inside and outside of a cell: •The zero reference point is outside the cell. •The inside of the cell is negative compared to the ref. •All cells have a membrane potential •In excitable cells (neurons and muscle cells) it is particularly impor ...
CH05_Lecture
... • Some molecules need to be moved against their concentration gradient • Requires energy – ATP is used directly or indirectly to fuel active transport • Moves substances from low to high concentration (against the gradient) • Requires the use of highly selective carrier proteins ...
... • Some molecules need to be moved against their concentration gradient • Requires energy – ATP is used directly or indirectly to fuel active transport • Moves substances from low to high concentration (against the gradient) • Requires the use of highly selective carrier proteins ...
Simplified view of how a neuron sends a signal
... thin, delicate extensions of the plasma membrane. In the drawing, upon receiving a stimulus from a cell to its left (e.g. one in the eye's retina), the neuron would send a signal (impulse) down its axon, from left to right, to a target cell, which would respond. The type of response would depend on ...
... thin, delicate extensions of the plasma membrane. In the drawing, upon receiving a stimulus from a cell to its left (e.g. one in the eye's retina), the neuron would send a signal (impulse) down its axon, from left to right, to a target cell, which would respond. The type of response would depend on ...
Ch3-4 Cell membrane
... Active Transport - uses ATP energy to move solutes across a membrane. It also requires the assistance of carrier proteins. 1) Channel proteins Channel proteins: form pores in the lipid bi-layer allowing certain ions to cross the membrane. These channel proteins are specialized and allow only part ...
... Active Transport - uses ATP energy to move solutes across a membrane. It also requires the assistance of carrier proteins. 1) Channel proteins Channel proteins: form pores in the lipid bi-layer allowing certain ions to cross the membrane. These channel proteins are specialized and allow only part ...
Traffic across Membranes-2008
... from the originals by permission of the publisher. These illustrations may not be reproduced in any format for any purpose without express written permission from the publisher. BIOLOGY: CONCEPTS AND CONNECTIONS 4th Edition, by Campbell, Reece, Mitchell, and Taylor, ©2001. These images have been pro ...
... from the originals by permission of the publisher. These illustrations may not be reproduced in any format for any purpose without express written permission from the publisher. BIOLOGY: CONCEPTS AND CONNECTIONS 4th Edition, by Campbell, Reece, Mitchell, and Taylor, ©2001. These images have been pro ...
Transportation Through the Plasma Membrane
... Some materials move between the _______________________________. c. some materials move through the ________________________________. ...
... Some materials move between the _______________________________. c. some materials move through the ________________________________. ...
Synapses - UBC Zoology
... • 80-90% of all presynaptic terminals terminate on dendrites • Most can't produce action potentials (too few or no Na+ channels) • Transmit current by passive spread down dendrites to the soma • Therefore the membrane potential decreases as move along dendrite due to current loss thanks to our frien ...
... • 80-90% of all presynaptic terminals terminate on dendrites • Most can't produce action potentials (too few or no Na+ channels) • Transmit current by passive spread down dendrites to the soma • Therefore the membrane potential decreases as move along dendrite due to current loss thanks to our frien ...
INTEGUMENTARY SYSTEM - Coast Colleges Home Page
... Na+ Channels Close, K+ Channels Open & K+ Diffuses Out of Neuron Results In Repolarization (+ outside/- inside) Repolarization Required before another Action Potential Sodium-Potassium Pump moves Na+ out & K+ in (Requires Energy) ...
... Na+ Channels Close, K+ Channels Open & K+ Diffuses Out of Neuron Results In Repolarization (+ outside/- inside) Repolarization Required before another Action Potential Sodium-Potassium Pump moves Na+ out & K+ in (Requires Energy) ...
INTEGUMENTARY SYSTEM
... Na+ Channels Close, K+ Channels Open & K+ Diffuses Out of Neuron Results In Repolarization (+ outside/- inside) Repolarization Required before another Action Potential Sodium-Potassium Pump moves Na+ out & K+ in (Requires Energy) ...
... Na+ Channels Close, K+ Channels Open & K+ Diffuses Out of Neuron Results In Repolarization (+ outside/- inside) Repolarization Required before another Action Potential Sodium-Potassium Pump moves Na+ out & K+ in (Requires Energy) ...
The Plasma Membrane
... Selectively permeable cell membranes allow certain molecules or ions to pass through it by active or passive transport. Active transport processes require the cell to expend energy to move the materials, while passive transport can be done without using cellular energy. Note that the membrane can ...
... Selectively permeable cell membranes allow certain molecules or ions to pass through it by active or passive transport. Active transport processes require the cell to expend energy to move the materials, while passive transport can be done without using cellular energy. Note that the membrane can ...
Title: Nervous System
... The nervous system carries out a complex array of tasks, such a sensing various smells, producing speech, remembering, providing signals that control body movements, and regulating the operation of internal organs. 1. Sensory function. 2. Integrative function. 3. Motor function ...
... The nervous system carries out a complex array of tasks, such a sensing various smells, producing speech, remembering, providing signals that control body movements, and regulating the operation of internal organs. 1. Sensory function. 2. Integrative function. 3. Motor function ...
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.