L9-Student AcidBase
... This is different from the mechanism in the proximal tubule and the loop of Henle. This primary active transport occurs in specialized cells called intercalated cells. Although the late distal tubule and collecting duct only make up 5 % of the total H+ ions secreted, the [H+] can be concentrated h ...
... This is different from the mechanism in the proximal tubule and the loop of Henle. This primary active transport occurs in specialized cells called intercalated cells. Although the late distal tubule and collecting duct only make up 5 % of the total H+ ions secreted, the [H+] can be concentrated h ...
Chapter_03_4E
... • Cell is more permeable to K+, thus K+ ions can move more freely • In an attempt to establish equilibrium, K+ will move outside the cell • Sodium-potassium pump actively transports K+ into and Na+ out of the cell to maintain the RMP • RMP is maintained at –70mV ...
... • Cell is more permeable to K+, thus K+ ions can move more freely • In an attempt to establish equilibrium, K+ will move outside the cell • Sodium-potassium pump actively transports K+ into and Na+ out of the cell to maintain the RMP • RMP is maintained at –70mV ...
Diffusion and Osmosis - FSCJ - Library Learning Commons
... Osmotic Pressure is the pressure that must be exerted on the hypertonic side of a selectively permeable membrane to prevent diffusion of water (by osmosis) from the side containing pure water. In animal ...
... Osmotic Pressure is the pressure that must be exerted on the hypertonic side of a selectively permeable membrane to prevent diffusion of water (by osmosis) from the side containing pure water. In animal ...
RBC_memb
... to form heterodimers which then selfassociate head to head to form tetramers. These tetramersare linked at the tail end to actin and are attached to protein band ...
... to form heterodimers which then selfassociate head to head to form tetramers. These tetramersare linked at the tail end to actin and are attached to protein band ...
The Cell Membrane
... Cell (compared to beaker) hypertonic or hypotonic Beaker (compared to cell) hypertonic or hypotonic Which way does the water flow? in or out of cell AP Biology ...
... Cell (compared to beaker) hypertonic or hypotonic Beaker (compared to cell) hypertonic or hypotonic Which way does the water flow? in or out of cell AP Biology ...
File
... Animation from: http://www.cat.cc.md.us/courses/bio141/lecguide/unit1/eustruct/images/sppump.gif ...
... Animation from: http://www.cat.cc.md.us/courses/bio141/lecguide/unit1/eustruct/images/sppump.gif ...
File
... no difference in concentration of water between cell & environment cell in equilibrium example: blood problem: none water flows across membrane equally, in both directions volume of cell doesn’t change ...
... no difference in concentration of water between cell & environment cell in equilibrium example: blood problem: none water flows across membrane equally, in both directions volume of cell doesn’t change ...
Overview of the Nervous System (the most important system in the
... An action potential (AP) propagates over the surface of the axon membrane Na+ flows into the cell causing a dramatic depolarization In response to depolarization, adjacent voltage-gated Na+ and K+ channels open, selfpropagating along the membrane K+ flows out of the cell causing a dramatic hyp ...
... An action potential (AP) propagates over the surface of the axon membrane Na+ flows into the cell causing a dramatic depolarization In response to depolarization, adjacent voltage-gated Na+ and K+ channels open, selfpropagating along the membrane K+ flows out of the cell causing a dramatic hyp ...
48_lecture_presentation - Course
... artificial membrane that separates two chambers. • At equilibrium, both the electrical and chemical gradients are balanced. • In a resting neuron, the currents of K+ and Na+ are equal and opposite, and the resting potential across the membrane remains steady. ...
... artificial membrane that separates two chambers. • At equilibrium, both the electrical and chemical gradients are balanced. • In a resting neuron, the currents of K+ and Na+ are equal and opposite, and the resting potential across the membrane remains steady. ...
Open Document - Clinton Community College
... Neuron at rest: ◦ Slightly negative charge ◦ Contains ions flowing back and forth ...
... Neuron at rest: ◦ Slightly negative charge ◦ Contains ions flowing back and forth ...
Exam I
... Short answer questions 27) (6 pts) John was having one of his cholinergic (releases acetylcholine) neurons (X) signal a postsynaptic neuron (Y). But now he wants neuron Y to stop receiving the signals. Besides having neuron X stop sending action potentials down to the terminal, what other things mus ...
... Short answer questions 27) (6 pts) John was having one of his cholinergic (releases acetylcholine) neurons (X) signal a postsynaptic neuron (Y). But now he wants neuron Y to stop receiving the signals. Besides having neuron X stop sending action potentials down to the terminal, what other things mus ...
Answers to Mastering Concepts Questions
... electrical potential that measures around -70 mV. 4. What causes the wave of depolarization and repolarization constituting an action potential? How does the membrane restore its resting potential? Once enough sodium enters to depolarize the trigger zone’s membrane to the threshold potential (about ...
... electrical potential that measures around -70 mV. 4. What causes the wave of depolarization and repolarization constituting an action potential? How does the membrane restore its resting potential? Once enough sodium enters to depolarize the trigger zone’s membrane to the threshold potential (about ...
Solutions - ISpatula
... nervous system to the CNS after transduction of the energy of the stimulus into a receptor potential. If the sensory receptors cell themselves are specialized neurons, the action potential will be directly produced and since they have axons they will extend to the CNS. If the sensory neuron is a sep ...
... nervous system to the CNS after transduction of the energy of the stimulus into a receptor potential. If the sensory receptors cell themselves are specialized neurons, the action potential will be directly produced and since they have axons they will extend to the CNS. If the sensory neuron is a sep ...
Modeling Membrane Movements
... 2. Describe the function of cell organelles and structures in a cell, in terms of life processes, and use models to explain these processes and their applications compare passive transport of matter by diffusion and osmosis with active transport in terms of the particle model of matter, concentrat ...
... 2. Describe the function of cell organelles and structures in a cell, in terms of life processes, and use models to explain these processes and their applications compare passive transport of matter by diffusion and osmosis with active transport in terms of the particle model of matter, concentrat ...
Nervous System - Dr. Eric Schwartz
... balance (Figure 6–13c). Because the membrane potential is not equal to the equilibrium potential for either ion, there is a small but steady leak of Na+ into the cell and K+ out of the cell. • The concentration gradients do not dissipate over time, however, because ion movement by the Na+/K+-ATPase ...
... balance (Figure 6–13c). Because the membrane potential is not equal to the equilibrium potential for either ion, there is a small but steady leak of Na+ into the cell and K+ out of the cell. • The concentration gradients do not dissipate over time, however, because ion movement by the Na+/K+-ATPase ...
Biophysical Investigation on Left Ventricular
... (Fig. 1). To monitor pyrene mobility in the membrane or vesicle lipid bilayer, pyrene solution was introduced into the membrane suspension and incubated for 20 min at room temperature. Fluorescence of pyrene-labeled samples was excited at 339 nm and emission recorded in the range of 350-550 nm (2.5- ...
... (Fig. 1). To monitor pyrene mobility in the membrane or vesicle lipid bilayer, pyrene solution was introduced into the membrane suspension and incubated for 20 min at room temperature. Fluorescence of pyrene-labeled samples was excited at 339 nm and emission recorded in the range of 350-550 nm (2.5- ...
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.