Biology 251 Fall 2015 1 TOPIC 4: ACTION POTENTIALS AND
... However, very few K+ and Na+ actually cross the membrane during an action potential compared to total amount of these ions available (only about 1 out of every 100,000 ions crosses the membrane) so their overall concentration is not changed much. ...
... However, very few K+ and Na+ actually cross the membrane during an action potential compared to total amount of these ions available (only about 1 out of every 100,000 ions crosses the membrane) so their overall concentration is not changed much. ...
Prokaryotes
... branch closest to the root of the universal tree ii. Euryarchaeota collection of the major archaeal phenotypes dominated by methanogens and extreme halophiles ...
... branch closest to the root of the universal tree ii. Euryarchaeota collection of the major archaeal phenotypes dominated by methanogens and extreme halophiles ...
7.012 Problem Set 6 FRIDAY November 19, 2004 Problem sets will
... g) The voltage-sensitive sodium channel has an inactivated state, in which the channel is not only closed, but also unable to open in response to depolarization. When does the channel shift into this conformation? What effect does this have on the direction of propagation of the action potential? Th ...
... g) The voltage-sensitive sodium channel has an inactivated state, in which the channel is not only closed, but also unable to open in response to depolarization. When does the channel shift into this conformation? What effect does this have on the direction of propagation of the action potential? Th ...
action potential
... Whole-animal integration = selective combination and processing of sensory, endocrine, and central nervous system (CNS) information in ways that promote harmonious functioning of the whole organism within its environment. ◦ This includes its all its cells, tissues, and organs ...
... Whole-animal integration = selective combination and processing of sensory, endocrine, and central nervous system (CNS) information in ways that promote harmonious functioning of the whole organism within its environment. ◦ This includes its all its cells, tissues, and organs ...
Resting membrane potential,Sensory receptors Action potential
... cell – high K+ and low Na+ concentration Constantly active K-Na pump: Na+ moves out, K+ moves in Selectively permeable membrane: the cell membrane is more permeable for Potassium ions than Sodium ions Non-diffusible ions (proteins and nucleic acids) with negative charge are in the cell ...
... cell – high K+ and low Na+ concentration Constantly active K-Na pump: Na+ moves out, K+ moves in Selectively permeable membrane: the cell membrane is more permeable for Potassium ions than Sodium ions Non-diffusible ions (proteins and nucleic acids) with negative charge are in the cell ...
Lecture: 10-14-16
... 1. Membranes are sheet‐like structures, two molecules thick that form closed boundaries between different compartments. Thickness of most membranes are between 6‐10 nm 2. Membranes are composed of lipids and proteins, either of which can be decorated with carbohydrates. 3. Membrane lipids are sma ...
... 1. Membranes are sheet‐like structures, two molecules thick that form closed boundaries between different compartments. Thickness of most membranes are between 6‐10 nm 2. Membranes are composed of lipids and proteins, either of which can be decorated with carbohydrates. 3. Membrane lipids are sma ...
HOW DOES AN ION CHANNEL WORK?
... some imagination like a green paprika. The channel is located from the bottom to the top of the paprika. At the bottom is the intracellular site (inside of the cell) and at the top is the extracellular side (outside of the cell). The journey that a potassium ion has travel from the inside to the out ...
... some imagination like a green paprika. The channel is located from the bottom to the top of the paprika. At the bottom is the intracellular site (inside of the cell) and at the top is the extracellular side (outside of the cell). The journey that a potassium ion has travel from the inside to the out ...
The Application of Systems Biology to Safety Assessment
... Better understanding of potential risks in patients (or subsets of patients) ...
... Better understanding of potential risks in patients (or subsets of patients) ...
Homeostasis & Transport
... The equal concentration of molecules throughout the space they occupy Random movement of molecules continues at equilibrium but there is no concentration gradient Molecules are just as likely to move in one direction as in any other ...
... The equal concentration of molecules throughout the space they occupy Random movement of molecules continues at equilibrium but there is no concentration gradient Molecules are just as likely to move in one direction as in any other ...
Chemical Properties of the Divalent Cation Binding Site on
... the activation of squid axon K channels by an amount equivalent to an ~ 25-mV depolarization of the membrane potential. In contrast, channel deactivation was altered by an amount equivalent to only a 4-mV potential change. The usual surface charge models predict equal shifts of these parameters. Oth ...
... the activation of squid axon K channels by an amount equivalent to an ~ 25-mV depolarization of the membrane potential. In contrast, channel deactivation was altered by an amount equivalent to only a 4-mV potential change. The usual surface charge models predict equal shifts of these parameters. Oth ...
outline
... 1) Bacteria – divide into 2 groups based on a cell wall molecule called peptidoglycan (=murein) Gram positive Gram negative 2) Archaea – no peptidoglycan, some have pseudomurein, chondroitin sulfate, or protein 7. Structures External to Cell Wall – not all external structures are found in all Bacter ...
... 1) Bacteria – divide into 2 groups based on a cell wall molecule called peptidoglycan (=murein) Gram positive Gram negative 2) Archaea – no peptidoglycan, some have pseudomurein, chondroitin sulfate, or protein 7. Structures External to Cell Wall – not all external structures are found in all Bacter ...
membrane structure n function
... Most trans-membrane proteins are thought to extend across the bilayer as (1) a single a helix, (2) as multiple a helices, or (3) as a rolled-up beta sheet . Some of these "single-pass" and "multipass" proteins have a covalently attached fatty acid chain inserted in the cytosolic lipid monolayer (1). ...
... Most trans-membrane proteins are thought to extend across the bilayer as (1) a single a helix, (2) as multiple a helices, or (3) as a rolled-up beta sheet . Some of these "single-pass" and "multipass" proteins have a covalently attached fatty acid chain inserted in the cytosolic lipid monolayer (1). ...
cell membrane
... • The polar heads are attracted to the water, so they point toward the surfaces of the lipid bilayer. – One layer of polar heads faces the cytoplasm, while the other layer is in contact with the cell’s immediate surroundings. ...
... • The polar heads are attracted to the water, so they point toward the surfaces of the lipid bilayer. – One layer of polar heads faces the cytoplasm, while the other layer is in contact with the cell’s immediate surroundings. ...
chapter 8 neuronal physiology B
... strength of the stimulating event • Depolarization wave known as local current flow • Strength depends on how much charge enters the cell • Decreases in strength as it travels through the cytoplasm • Can be depolarizing or hyperpolarizing ...
... strength of the stimulating event • Depolarization wave known as local current flow • Strength depends on how much charge enters the cell • Decreases in strength as it travels through the cytoplasm • Can be depolarizing or hyperpolarizing ...
five structure-function classes of membrane proteins
... transporters is the 12 TMH family with several hundred examples. A web site that has a comprehensive list of all the known transport proteins (over 2000 from some 350 species ) is that of Milton Saier. (www-biology.ucsd.edu~msaier/transport/titlepage2.html) It is attached. They are listed so that ea ...
... transporters is the 12 TMH family with several hundred examples. A web site that has a comprehensive list of all the known transport proteins (over 2000 from some 350 species ) is that of Milton Saier. (www-biology.ucsd.edu~msaier/transport/titlepage2.html) It is attached. They are listed so that ea ...
Biological Membranes
... swell as water leaves or enters the cell Osmotic pressure- the tendency for water to move into any cell ...
... swell as water leaves or enters the cell Osmotic pressure- the tendency for water to move into any cell ...
Cell Communication Presentation- Marine Cone Snail (Toxin)
... s/molecular_neurobiology/Forschung/Ttoxins_illustration_for_HP_english.jpg ...
... s/molecular_neurobiology/Forschung/Ttoxins_illustration_for_HP_english.jpg ...
بسم الله الرحمن الرحیم The Plasma Membrane Membrane Functions
... Can comprise up to 50% of animal plasma membrane Hydrophilic OH groups toward surface Smaller than a phospholipid and less amphipathic (having both polar and non-polar regions of the molecule) Other molecules include ceramides and sphingolipds - amino alcohols with fatty ...
... Can comprise up to 50% of animal plasma membrane Hydrophilic OH groups toward surface Smaller than a phospholipid and less amphipathic (having both polar and non-polar regions of the molecule) Other molecules include ceramides and sphingolipds - amino alcohols with fatty ...
Reading Notes 11
... Upon reaching the postsynaptic membrane, the neurotransmitters bind to specific receptor _______________ in this membrane. ...
... Upon reaching the postsynaptic membrane, the neurotransmitters bind to specific receptor _______________ in this membrane. ...
Unit 1 Cell and Molecular Bioligy
... a) Strengthening and supporting cell membrane. These determine the shape of the cell and the mechanical properties of the PM in particular which is covered in the inner (cytosolic) surface by a meshwork of fibrous proteins called the cell cortex b) Joining cells together into strong layers or tissue ...
... a) Strengthening and supporting cell membrane. These determine the shape of the cell and the mechanical properties of the PM in particular which is covered in the inner (cytosolic) surface by a meshwork of fibrous proteins called the cell cortex b) Joining cells together into strong layers or tissue ...
AQUAPORINS – USEFUL LEADS TO LOW ENERGY
... re-absorbed by a series of mechanisms where the NPA motifs contact each other so that finally about 1 L of urine a day (Fujiyoshi et al., 2002). The right-handed leaves the body. From the glomeruli, arrangement of the α-helices was initially primary urine is passed on through a controversial, but ot ...
... re-absorbed by a series of mechanisms where the NPA motifs contact each other so that finally about 1 L of urine a day (Fujiyoshi et al., 2002). The right-handed leaves the body. From the glomeruli, arrangement of the α-helices was initially primary urine is passed on through a controversial, but ot ...
Plant K Channel Proteins
... corresponding domains of Kcsa. The three-dimensional structures of the Kselective channel Kcsa and the plant cngc AtCNGC2 are nearly identical; the exception is the selectivity filter of the two channels. Kcsa, and other (plant and animal) K-selective channels have the amino acid triplet ‘GYG’ withi ...
... corresponding domains of Kcsa. The three-dimensional structures of the Kselective channel Kcsa and the plant cngc AtCNGC2 are nearly identical; the exception is the selectivity filter of the two channels. Kcsa, and other (plant and animal) K-selective channels have the amino acid triplet ‘GYG’ withi ...
Review Form - Saddleback College
... The hypothesis of this investigation was that introducing mutations A477V/L480M into SK2 channels would increase the potency of Riluzole and further show that this mutation serves as the functional binding pocket in which Riluzole exerts its modulation. SK2 channels with the mutation show a lesser a ...
... The hypothesis of this investigation was that introducing mutations A477V/L480M into SK2 channels would increase the potency of Riluzole and further show that this mutation serves as the functional binding pocket in which Riluzole exerts its modulation. SK2 channels with the mutation show a lesser a ...
Slide 1
... Mode of interaction is based upon specific properties of the peptide and target membrane Many microbial antibiotics are peptides that form cationic amphipathic secondary structures that interact with negatively charged bacterial membranes via aid of electrostatic interactions. – form pores, leading ...
... Mode of interaction is based upon specific properties of the peptide and target membrane Many microbial antibiotics are peptides that form cationic amphipathic secondary structures that interact with negatively charged bacterial membranes via aid of electrostatic interactions. – form pores, leading ...
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.