Nerves and Muscles
... The Facts • Out side the nerve membrane is positive due to Sodium ions • Inside the membrane has positive potassium ions but also ...
... The Facts • Out side the nerve membrane is positive due to Sodium ions • Inside the membrane has positive potassium ions but also ...
Recitation 2 Solutions
... Also, if carbohydrates were stored as monosaccharides, instead of polysaccharides, they would exert much higher osmotic pressure on the cell. For example 1000 glucose molecule would exert 1000 times the osmotic pressure of a single glycogen molecule, causing water to move in. If it were not for poly ...
... Also, if carbohydrates were stored as monosaccharides, instead of polysaccharides, they would exert much higher osmotic pressure on the cell. For example 1000 glucose molecule would exert 1000 times the osmotic pressure of a single glycogen molecule, causing water to move in. If it were not for poly ...
Membranes - hrsbstaff.ednet.ns.ca
... • Diffusion: the movement of particles from the area of greater concentration to an area of lesser concentration to form dynamic equilibrium. • Dynamic Equilibrium: condition of continuous movement with no net change. • Osmosis: the movement of water across a semipermeable membrane from an area of g ...
... • Diffusion: the movement of particles from the area of greater concentration to an area of lesser concentration to form dynamic equilibrium. • Dynamic Equilibrium: condition of continuous movement with no net change. • Osmosis: the movement of water across a semipermeable membrane from an area of g ...
2008 marking scheme
... Discuss the biological importance of sensory adaptation and outline the adaptation mechanisms in a variety of biological transducers. Adaptation is required for three main reasons: (1) biological transducers must operate over a wide dynamic range, (2) changes in the input signal have greater biologi ...
... Discuss the biological importance of sensory adaptation and outline the adaptation mechanisms in a variety of biological transducers. Adaptation is required for three main reasons: (1) biological transducers must operate over a wide dynamic range, (2) changes in the input signal have greater biologi ...
Nerve Impulse Notes
... • Sodium (Na+) channels open allowing Na+ to diffuse into the cell quickly • This causes the inside to become + (outside -) • Repolarize: Normalizing • K+ gates open in order to allow K+ to diffuse out of the cell – this restores the membrane (+ outside, - inside) ...
... • Sodium (Na+) channels open allowing Na+ to diffuse into the cell quickly • This causes the inside to become + (outside -) • Repolarize: Normalizing • K+ gates open in order to allow K+ to diffuse out of the cell – this restores the membrane (+ outside, - inside) ...
Objectives The Synapse Associated terms Types of Synapses
... *Neurotransmitters associated with behavioral states, such as mood, tension, learning and memory. ...
... *Neurotransmitters associated with behavioral states, such as mood, tension, learning and memory. ...
Ch 2 lec 3
... 2) Metabotropic Receptors Slower variety (short cut faster than second messenger system) • Actions are reliant on activation of G-proteins located in the internal membrane of the postsynaptic cell • 2 basic varieties: 1) short cut 2) second messenger ...
... 2) Metabotropic Receptors Slower variety (short cut faster than second messenger system) • Actions are reliant on activation of G-proteins located in the internal membrane of the postsynaptic cell • 2 basic varieties: 1) short cut 2) second messenger ...
Nervous System: General Principles
... • Electrical signal (action potential (AP)) descends axon to synaptic knob (nerve end) • Depolarization opens Ca++ channels to open in presynaptic membrane • Triggers a number of synaptic vesicles to fuse with outer membrane • Dumps neurotransmitter (NT) into synaptic cleft • NT diffuses across clef ...
... • Electrical signal (action potential (AP)) descends axon to synaptic knob (nerve end) • Depolarization opens Ca++ channels to open in presynaptic membrane • Triggers a number of synaptic vesicles to fuse with outer membrane • Dumps neurotransmitter (NT) into synaptic cleft • NT diffuses across clef ...
Copyright © 2008 by John Wiley & Sons, Inc.
... and interact with K+ ions selectively Each ring contains four O atoms, and each ring is just large enough so that 8 O atoms can coordinate a single K+ ions, replacing its normal water of hydration ...
... and interact with K+ ions selectively Each ring contains four O atoms, and each ring is just large enough so that 8 O atoms can coordinate a single K+ ions, replacing its normal water of hydration ...
Manual
... Gramicidin channel formation occurs as seen in Figure (0.4) by two peptides linked head to head by hydrogen bonds, each forming a half channel. The tryptophan residues along the channel are both hydrophobic as well as capable of long range electrostatic interactions. The activity of the channel meas ...
... Gramicidin channel formation occurs as seen in Figure (0.4) by two peptides linked head to head by hydrogen bonds, each forming a half channel. The tryptophan residues along the channel are both hydrophobic as well as capable of long range electrostatic interactions. The activity of the channel meas ...
C. The Action Potential
... Question 2. (points: 2) Why doesn’t this second pulse cause a second spike? Phrase your answer in terms of gates and voltages. Consider the plot (yellow, green, and cyan lines) of m, h and n below the voltage. Recall that the fast sodium channel conductance is proportional to m3 h, and potassium ch ...
... Question 2. (points: 2) Why doesn’t this second pulse cause a second spike? Phrase your answer in terms of gates and voltages. Consider the plot (yellow, green, and cyan lines) of m, h and n below the voltage. Recall that the fast sodium channel conductance is proportional to m3 h, and potassium ch ...
Brief Review of Membrane Structure and Osmosis Cells and cell
... Substances that cross the membrane through specific channels In contrast, ions such Na+ or Cl- are unable to cross the membrane freely. Special channels are required for these substances to cross the cell membrane. These channels are proteins imbedded in the membrane. When ions are passing through ...
... Substances that cross the membrane through specific channels In contrast, ions such Na+ or Cl- are unable to cross the membrane freely. Special channels are required for these substances to cross the cell membrane. These channels are proteins imbedded in the membrane. When ions are passing through ...
Cell signalling
... LIGAND-GATED ION CHANNELS • chemical stimuli bind to receptor and open or close ion channel • stimuli can be extracellular or intracellular EXTRACELLULAR STIMULI: (neurotransmitters) – e.g. acetylcholine, dopamine, GABA, glutamate INTRACELLULAR STIMULI: (second messengers) – e.g. IP3, cAMP, cGMP, C ...
... LIGAND-GATED ION CHANNELS • chemical stimuli bind to receptor and open or close ion channel • stimuli can be extracellular or intracellular EXTRACELLULAR STIMULI: (neurotransmitters) – e.g. acetylcholine, dopamine, GABA, glutamate INTRACELLULAR STIMULI: (second messengers) – e.g. IP3, cAMP, cGMP, C ...
16-17 membrane notes
... FLUID MOSAIC MODEL • Current model for animal plasma membrane • Held together by weak phobic interactions that make membrane fluid • Components can move laterally ...
... FLUID MOSAIC MODEL • Current model for animal plasma membrane • Held together by weak phobic interactions that make membrane fluid • Components can move laterally ...
Worksheet 1
... of post synaptic receptors and ion channels as well as the half life of the neurotransmitter in the synaptic cleft. In electrical synapses, the signal must go from a larger cell to smaller cell. This is because (p177) the current that depolarizes the postsynaptic cell is generated directly by the vo ...
... of post synaptic receptors and ion channels as well as the half life of the neurotransmitter in the synaptic cleft. In electrical synapses, the signal must go from a larger cell to smaller cell. This is because (p177) the current that depolarizes the postsynaptic cell is generated directly by the vo ...
H/Ws 1 to 4
... therefore a small proportion of cell and ratio of membrane surface area to cytosolic volume is great, even for a large plant. Q: What is the fluid mosaic model? A: A membrane and various proteins embedded or attached to the double phospholipids layer. Q: Why a bilayer? A: This arrangement allows for ...
... therefore a small proportion of cell and ratio of membrane surface area to cytosolic volume is great, even for a large plant. Q: What is the fluid mosaic model? A: A membrane and various proteins embedded or attached to the double phospholipids layer. Q: Why a bilayer? A: This arrangement allows for ...
Chapter 5
... repels polar molecules but not nonpolar molecules – Nonpolar molecules will move until the concentration is equal on both sides – Limited permeability to small polar molecules – Very limited permeability to larger polar molecules and ions ...
... repels polar molecules but not nonpolar molecules – Nonpolar molecules will move until the concentration is equal on both sides – Limited permeability to small polar molecules – Very limited permeability to larger polar molecules and ions ...
resting potential and chloride channels
... While muscle cells have a resting potential of about –90 mV, most neurons have a resting potential of about –65 mV (range – 60 to –70 mV). The threshold for AP intiation is about –55 mV. The EPSP reversal potential (EEPSP) is about 0 mV (because glutamate non-NMDA receptors gate Na+ and K+). The siz ...
... While muscle cells have a resting potential of about –90 mV, most neurons have a resting potential of about –65 mV (range – 60 to –70 mV). The threshold for AP intiation is about –55 mV. The EPSP reversal potential (EEPSP) is about 0 mV (because glutamate non-NMDA receptors gate Na+ and K+). The siz ...
CNSIntro
... more positively charged ions outside, more negatively charged ions inside The ions responsible for the membrane potential include ...
... more positively charged ions outside, more negatively charged ions inside The ions responsible for the membrane potential include ...
Transmembrane Transport of Ions and Small Molecules
... • The animal cell plasma membrane resting potential is generated by the ATP-powered Na+/K+ pump and nongated K+ channels. • The structure and chemical nature of a channel pore lowers the activation energy for passage of a specific ion over other ions, which may be even smaller. • Patch-clamping tech ...
... • The animal cell plasma membrane resting potential is generated by the ATP-powered Na+/K+ pump and nongated K+ channels. • The structure and chemical nature of a channel pore lowers the activation energy for passage of a specific ion over other ions, which may be even smaller. • Patch-clamping tech ...
Mechanosensitive channels
Mechanosensitive channels or mechanosensitive ion channels are membrane proteins capable of responding to mechanical stress over a wide dynamic range of external mechanical stimuli. They are found in prokaryotes and eukaryotes. The channels vary in selectivity for the permeating ions from nonselective between anions and cations in bacteria, to cation selective allowing passage Ca2+, K+ and Na+ in eukaryotes, and highly selective K+ channels in bacteria and eukaryotes.All organisms, and apparently all cell types, sense and respond to mechanical stimuli. MSCs function as mechanotransducers capable of generating both electrical and ion flux signals as a response to external or internal stimuli. Under extreme turgor in bacteria, non selective MSCs such as MSCL and MSCS serve as safety valves to prevent lysis. In specialized cells of the higher organisms, other types of MSCs are probably the basis of the senses of hearing and touch and sense the stress needed for muscular coordination. However, none of these channels have been cloned. MSCs also allow plants to distinguish up from down by sensing the force of gravity. MSCs are not pressure-sensitive, but sensitive to local stress, most likely tension in the surrounding lipid bilayer.