The Nervous System
... Key Concepts and Important Terms • Nervous systems function in sensory input, integration, and motor output. • The nervous system is composed of neurons and supporting cells. • Membrane potentials arise from differences in ion concentrations between a cell’s contents and the extracellular fluid. • ...
... Key Concepts and Important Terms • Nervous systems function in sensory input, integration, and motor output. • The nervous system is composed of neurons and supporting cells. • Membrane potentials arise from differences in ion concentrations between a cell’s contents and the extracellular fluid. • ...
Hearing and Equilibrium Human Ear Major questions Anatomy of
... membrane--> stereocilia flex back and forth in or against tectorial membrane • Mechanical opening of ion channels ...
... membrane--> stereocilia flex back and forth in or against tectorial membrane • Mechanical opening of ion channels ...
Transport Across Cell Membrane
... Diffusion: All fluids (liquids + gases) move from area of higher concentration to area of lower concentration (concentration gradient). This movement of substances is called Diffusion. It can be through cell membranes. For example, spreading of fragrance, dissolving of ink drop in water, movement of ...
... Diffusion: All fluids (liquids + gases) move from area of higher concentration to area of lower concentration (concentration gradient). This movement of substances is called Diffusion. It can be through cell membranes. For example, spreading of fragrance, dissolving of ink drop in water, movement of ...
Membrane Domains and Membrane Potential
... Voltage-gated channels have gates that are controlled by changes in membrane potential. ...
... Voltage-gated channels have gates that are controlled by changes in membrane potential. ...
Cell Membranes: Chapt. 6
... Cell Membrane Every cell is encircled by a membrane and most cells contain an extensive intracellular membrane system. Membranes fence off the cell's interior from its surroundings. Membranes let in water, certain ions and substrates and they excrete waste substances. They act to protect the cell. ...
... Cell Membrane Every cell is encircled by a membrane and most cells contain an extensive intracellular membrane system. Membranes fence off the cell's interior from its surroundings. Membranes let in water, certain ions and substrates and they excrete waste substances. They act to protect the cell. ...
AP Biology - gwbiology
... unsaturated hydrocarbon tails, because the kinks from the double bonds in these tails cause the phospholipis to stay farther apart and more fluid then if they were closely packed together, as is the case with saturated hydrocarbon tails. Also, cholesterol is used in the membrane as a temperature buf ...
... unsaturated hydrocarbon tails, because the kinks from the double bonds in these tails cause the phospholipis to stay farther apart and more fluid then if they were closely packed together, as is the case with saturated hydrocarbon tails. Also, cholesterol is used in the membrane as a temperature buf ...
LECTURE NOTE ELECTRIC POTENTIAL
... FPR CALCULATIONS Ev SHOULD BE CONTINUED TO JOULES EX: 5000 Ev = 8.0 x 10-16 j/1.6 x 10-19 Ev USING eV TO STATE ENERGY IS FINE BUT TO MAKE FURTHER CALCULATIONS THE CONVERSION MUST BE MADE. ELECTRIC POTENTIAL DUE TO POINT CHARGES V=KQ/r K-COULOMB’S CONSTANT 9.0 X 109 N.M2/C2 K = 1/4Πεο POTENTIAL NEAR ...
... FPR CALCULATIONS Ev SHOULD BE CONTINUED TO JOULES EX: 5000 Ev = 8.0 x 10-16 j/1.6 x 10-19 Ev USING eV TO STATE ENERGY IS FINE BUT TO MAKE FURTHER CALCULATIONS THE CONVERSION MUST BE MADE. ELECTRIC POTENTIAL DUE TO POINT CHARGES V=KQ/r K-COULOMB’S CONSTANT 9.0 X 109 N.M2/C2 K = 1/4Πεο POTENTIAL NEAR ...
Ch. 10 Outline
... A. A cell membrane is usually electrically charged, or polarized, so that the inside of the membrane is negatively charged with respect to the outside of the membrane (which is then positively charged). B. This is as a result of unequal distribution of ions on the inside and the outside of the membr ...
... A. A cell membrane is usually electrically charged, or polarized, so that the inside of the membrane is negatively charged with respect to the outside of the membrane (which is then positively charged). B. This is as a result of unequal distribution of ions on the inside and the outside of the membr ...
lecture 21 - Biological and Soft Systems
... Richard Naud and Wulfram Gerstner tion threshold of the sodium current. Sodium ion channels responsible for the upswing of the action potential r ere the voltage threshold measured from a current pulse is significantly very fast. So fast that the time it takes to reach their voltage-dependent leve o ...
... Richard Naud and Wulfram Gerstner tion threshold of the sodium current. Sodium ion channels responsible for the upswing of the action potential r ere the voltage threshold measured from a current pulse is significantly very fast. So fast that the time it takes to reach their voltage-dependent leve o ...
Cell Membranes and Signaling
... may have different functions in its external and transmembrane domains. ...
... may have different functions in its external and transmembrane domains. ...
Structure of the Synapse
... threshold is reached then action potential is initated • Inhibitory ion channels - neuroreceptors are Cl- channels. When Cl- channels open, hyperpolarisation occurs, making action potential less likely • Non channel synapses - neuroreceptors are membrane-bound enzymes. When activated, they catalyse ...
... threshold is reached then action potential is initated • Inhibitory ion channels - neuroreceptors are Cl- channels. When Cl- channels open, hyperpolarisation occurs, making action potential less likely • Non channel synapses - neuroreceptors are membrane-bound enzymes. When activated, they catalyse ...
Chapter 5
... too large to pass through pores. May occur into or out of cell. Carrier proteins are specific to 1 type of molecule. Animation ...
... too large to pass through pores. May occur into or out of cell. Carrier proteins are specific to 1 type of molecule. Animation ...
Acc_Bio_4_1and4_2_ws
... Read the passage below. Notice that the sentences are numbered. Then answer the questions that follow. 1 The diffusion of water through a selectively permeable membrane is called osmosis. 2Like other forms of diffusion, osmosis involves the movement of a substance—water—down its concentration gradie ...
... Read the passage below. Notice that the sentences are numbered. Then answer the questions that follow. 1 The diffusion of water through a selectively permeable membrane is called osmosis. 2Like other forms of diffusion, osmosis involves the movement of a substance—water—down its concentration gradie ...
Cell Transport Notes Name: _______ Explore: What happens when
... Isotonic Solutions: the concentration of dissolved substances in the extracellular solution is __________________ as the concentration of dissolved substances inside the cell (in the cytoplasm). Hypotonic Solutions: the concentration of dissolved substances in the extracellular solution is _________ ...
... Isotonic Solutions: the concentration of dissolved substances in the extracellular solution is __________________ as the concentration of dissolved substances inside the cell (in the cytoplasm). Hypotonic Solutions: the concentration of dissolved substances in the extracellular solution is _________ ...
What is the cause of the changes in membrane potential during an
... Components within the compound action potential • Refractory period/Faithfulness of conduction ...
... Components within the compound action potential • Refractory period/Faithfulness of conduction ...
week4am
... see depolarization (change from negative inside neuron to more positive) ◦ “threshold” – if a great enough depolarization occurs, an action potential will occur ◦ action potential – very quick – milliseconds Other terms – spike, firing, generating an AP ...
... see depolarization (change from negative inside neuron to more positive) ◦ “threshold” – if a great enough depolarization occurs, an action potential will occur ◦ action potential – very quick – milliseconds Other terms – spike, firing, generating an AP ...
Document
... Na+ ions. • ATP is hydrolyzed, leading to phosphorylation of the pump at a highly conserved aspartate residue and subsequent release of ADP. • A conformational change in the pump exposes the Na+ ions to the outside. The phosphorylated form of the pump has a low affinity for Na+ ions, so they are rel ...
... Na+ ions. • ATP is hydrolyzed, leading to phosphorylation of the pump at a highly conserved aspartate residue and subsequent release of ADP. • A conformational change in the pump exposes the Na+ ions to the outside. The phosphorylated form of the pump has a low affinity for Na+ ions, so they are rel ...
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.