The Cell (aka Plasma) Membrane intro mini
... glycerol form the head, which is polar (charged) and hydrophilic (waterloving) • The two fatty acid chains form the tails, which are non-polar (not charged) and ...
... glycerol form the head, which is polar (charged) and hydrophilic (waterloving) • The two fatty acid chains form the tails, which are non-polar (not charged) and ...
13. What determines the magnitude of the graded potential? (p. 240)
... are located) and travel down to the axon terminal where they are housed in vesicles until signaled for release. When the appropriate signal (action potential) arrives, neurotransmitter is released via exocytosis. The neurotransmitter then travels by diffusion to the postsynaptic membrane where it op ...
... are located) and travel down to the axon terminal where they are housed in vesicles until signaled for release. When the appropriate signal (action potential) arrives, neurotransmitter is released via exocytosis. The neurotransmitter then travels by diffusion to the postsynaptic membrane where it op ...
Membrane Function Review
... DIFFUSION. This is when molecules cross the membrane through ___________ ___________. The type of molecules that go through the membrane are ___________ (give examples: _______________________) OR ___________ (give examples: ________________________). The third form of passive transport, OSMOSIS, sp ...
... DIFFUSION. This is when molecules cross the membrane through ___________ ___________. The type of molecules that go through the membrane are ___________ (give examples: _______________________) OR ___________ (give examples: ________________________). The third form of passive transport, OSMOSIS, sp ...
Outer Hair Cells
... • Potassium flows into cell • Calcium flows into cell • Voltage shifts to a less negative value • More neurotransmitter is released ...
... • Potassium flows into cell • Calcium flows into cell • Voltage shifts to a less negative value • More neurotransmitter is released ...
Objectives The Synapse Associated terms Types of Synapses
... Neurotransmitter release 1) VG Calcium channels open (region of synaptic bulb). 2) Neurotransmitter is released via vesicles that undergo exocytosis. 3) Ntrans binds to postsynaptic receptors on the PM. 4) Ion channels open in the postsynaptic membrane, creating a different electrical environment ...
... Neurotransmitter release 1) VG Calcium channels open (region of synaptic bulb). 2) Neurotransmitter is released via vesicles that undergo exocytosis. 3) Ntrans binds to postsynaptic receptors on the PM. 4) Ion channels open in the postsynaptic membrane, creating a different electrical environment ...
Cell Structure and Membrane Transport Study Guide
... Cell Theory: Know the three parts of the theory. Prokaryotic vs. Eukaryotic Cells: Bacteria are prokaryotic, do not have nucleus or other membranebound organelles. Do have cell membrane and ribosomes. Importance of Surface Area: Limits how much can enter or leave the cell. Ratio of surface area to v ...
... Cell Theory: Know the three parts of the theory. Prokaryotic vs. Eukaryotic Cells: Bacteria are prokaryotic, do not have nucleus or other membranebound organelles. Do have cell membrane and ribosomes. Importance of Surface Area: Limits how much can enter or leave the cell. Ratio of surface area to v ...
Membrane potential (mV)
... Anions (negatively charged proteins, nucleic acids, and other large molecules) that cannot pass through membrane ...
... Anions (negatively charged proteins, nucleic acids, and other large molecules) that cannot pass through membrane ...
Lecture 11b Neurophysiology
... coming in through chemically gated channels (graded potential) depolarize the membrane causing voltage gated Na+ channels to open. • Voltage-gated Na+ channels allow more Na+ in, this depolarizes the membrane more, opens more voltage-gated Na+ channels, etc. • Na+ indepolarizationopens Na+ channel ...
... coming in through chemically gated channels (graded potential) depolarize the membrane causing voltage gated Na+ channels to open. • Voltage-gated Na+ channels allow more Na+ in, this depolarizes the membrane more, opens more voltage-gated Na+ channels, etc. • Na+ indepolarizationopens Na+ channel ...
Lecture 11b Neurophysiology
... • So K+ leaves the cell continuously, but will it reach concentration equilibrium (same conc. on both sides)? • NO, because as + ions leave, they leave behind an excess of negative charge and an electrical potential develops (due to separation of + and – charges) which is EQUAL and OPPOSITE to the c ...
... • So K+ leaves the cell continuously, but will it reach concentration equilibrium (same conc. on both sides)? • NO, because as + ions leave, they leave behind an excess of negative charge and an electrical potential develops (due to separation of + and – charges) which is EQUAL and OPPOSITE to the c ...
electrochemical impulse
... known as a stimulus, it has to be strong enough to trigger the depolarization of the membrane. • The intensity of the stimulus must reach a set level called the threshold level before the signal will be sent. This threshold is important for it prevents small changes that don’t have an effect from se ...
... known as a stimulus, it has to be strong enough to trigger the depolarization of the membrane. • The intensity of the stimulus must reach a set level called the threshold level before the signal will be sent. This threshold is important for it prevents small changes that don’t have an effect from se ...
Cell Physiology
... pores or cannot dissolve into the fatty portion of the membrane, they may have to move through a protein membrane channel or may have to use a carrier protein to complete their movement from high to low concentrations. ...
... pores or cannot dissolve into the fatty portion of the membrane, they may have to move through a protein membrane channel or may have to use a carrier protein to complete their movement from high to low concentrations. ...
I. Functions and Divisions of the Nervous System A. The nervous
... 2. The neuron cell body, also called the perikaryon or soma, is the major biosynthetic center containing the usual organelles except for centrioles. 3. Neurons have armlike processes that extend from the cell body. a. Dendrites are cell processes that are the receptive regions of the cell and provid ...
... 2. The neuron cell body, also called the perikaryon or soma, is the major biosynthetic center containing the usual organelles except for centrioles. 3. Neurons have armlike processes that extend from the cell body. a. Dendrites are cell processes that are the receptive regions of the cell and provid ...
BIOL241Neurophys11bJUL2012
... • Potential difference – voltage measured between two points • Current (I) – the flow of electrical charge between two points (carried by ions) • Resistance (R) – hindrance to charge flow • Insulator – substance with high electrical resistance (e.g. myelin) • Conductor – substance with low elec ...
... • Potential difference – voltage measured between two points • Current (I) – the flow of electrical charge between two points (carried by ions) • Resistance (R) – hindrance to charge flow • Insulator – substance with high electrical resistance (e.g. myelin) • Conductor – substance with low elec ...
AP Biology
... membrane has just been immersed in a beaker containing a different solution. The membrane is permeable to water and to the simple sugars glucose and fructose but completely impermeable to the disaccharide sucrose. ...
... membrane has just been immersed in a beaker containing a different solution. The membrane is permeable to water and to the simple sugars glucose and fructose but completely impermeable to the disaccharide sucrose. ...
Physiology of nerve & muscles
... The neuron - the basic structure unite of the nervous system - it is formed of cell body, dendrites & the axon Types of nerve fibers - myelinated nerve fibers - unmyelinated nerve fibers ...
... The neuron - the basic structure unite of the nervous system - it is formed of cell body, dendrites & the axon Types of nerve fibers - myelinated nerve fibers - unmyelinated nerve fibers ...
Biological Membranes
... 2. Dialysis – diffusion of a substance across a semipermeable membrane. 3. Osmosis – diffusion of water across a selectively permeable membrane. 4. Facilitated Diffusion – passive transport of ions or molecules by a specific carrier protein in a membrane. Transport proteins are similar to enzymes: a ...
... 2. Dialysis – diffusion of a substance across a semipermeable membrane. 3. Osmosis – diffusion of water across a selectively permeable membrane. 4. Facilitated Diffusion – passive transport of ions or molecules by a specific carrier protein in a membrane. Transport proteins are similar to enzymes: a ...
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.