CELL STRUCTURE_2012_crossing the
... This channel or carrier mediated movement is selective and can become saturated. This may inhibit the movement of another molecule. No energy is used. ...
... This channel or carrier mediated movement is selective and can become saturated. This may inhibit the movement of another molecule. No energy is used. ...
Dopamine axons of substantia nigra pars compacta neurons and
... selective vulnerability. One factor that distinguishes SNc DA neurons from other DA neurons is their massive axonal arbour and the massive number of synapses they establish. We propose that the high energy cost of such a massive axonal architecture puts SNc DA neurons energetically ‘on the edge’ suc ...
... selective vulnerability. One factor that distinguishes SNc DA neurons from other DA neurons is their massive axonal arbour and the massive number of synapses they establish. We propose that the high energy cost of such a massive axonal architecture puts SNc DA neurons energetically ‘on the edge’ suc ...
Chapter 7 Membrane Structure and Function
... • The release of material from vesicles at the cell surface. • Examples: protists using a contractile vacuole to release water, gland cells secreting ...
... • The release of material from vesicles at the cell surface. • Examples: protists using a contractile vacuole to release water, gland cells secreting ...
WATER POTENTIAL
... Makes it more _____________ Overall WATER POTENTIAL decreases too Water = more likely to flow toward areas with low water potential SOLUTE SUCKS! ...
... Makes it more _____________ Overall WATER POTENTIAL decreases too Water = more likely to flow toward areas with low water potential SOLUTE SUCKS! ...
Electrical Signaling
... Using Ions as Messengers • Important things to recall (and understand): – ions are just atoms with a charge, – membrane potentials are established by ionic charges (electrochemical gradients), – changes in charge can affect membrane proteins such as channels, – other membrane channels allow for ion ...
... Using Ions as Messengers • Important things to recall (and understand): – ions are just atoms with a charge, – membrane potentials are established by ionic charges (electrochemical gradients), – changes in charge can affect membrane proteins such as channels, – other membrane channels allow for ion ...
Lecture 1 st week
... Action of the transmitter substance on the postsynaptic neuron • The membrane of the postsynaptic neuron contains large numbers of receptor proteins with two components: – 1) a binding component (outward into the synaptic cleft—here it binds the neurotransmitter) – 2) an ionophore component (that p ...
... Action of the transmitter substance on the postsynaptic neuron • The membrane of the postsynaptic neuron contains large numbers of receptor proteins with two components: – 1) a binding component (outward into the synaptic cleft—here it binds the neurotransmitter) – 2) an ionophore component (that p ...
Osmosis and Diffusion
... QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. ...
... QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. ...
electric potential/eqipotential
... For a charged sphere of radius r, If the charge is symmetrically distributed, the potential outside a sphere of charge Q is given by the equation, V = kQ/r Where Q is the charge on the surface of the sphere. r radius of the sphere k is the coulomb’s constat = 8.89 * 10 -9 N m2 /c2 (k = 1/ 4 ∏ ε0 ; ε ...
... For a charged sphere of radius r, If the charge is symmetrically distributed, the potential outside a sphere of charge Q is given by the equation, V = kQ/r Where Q is the charge on the surface of the sphere. r radius of the sphere k is the coulomb’s constat = 8.89 * 10 -9 N m2 /c2 (k = 1/ 4 ∏ ε0 ; ε ...
Lecture 2 Powerpoint file
... • Graded potential – stimulation (usually a post-synaptic potential) causes Na+ to enter the cell, depolarizing the membrane – Na+ disperses along membrane, spreading depolarization ...
... • Graded potential – stimulation (usually a post-synaptic potential) causes Na+ to enter the cell, depolarizing the membrane – Na+ disperses along membrane, spreading depolarization ...
No Slide Title
... Membrane proteins at a glance Membrane proteins are simply those that exist in cell membranes. They can serve as structural supports, as both passive and active channels for ions and chemicals, or serve more specialized functions such as light reception. Fully one quarter of the human genome encode ...
... Membrane proteins at a glance Membrane proteins are simply those that exist in cell membranes. They can serve as structural supports, as both passive and active channels for ions and chemicals, or serve more specialized functions such as light reception. Fully one quarter of the human genome encode ...
WEEK 12 CP Cell_Transport_Bio
... Tuesday • What is the difference between active and passive transport? • Name the 3 types of passive transport. ...
... Tuesday • What is the difference between active and passive transport? • Name the 3 types of passive transport. ...
The Human Cell Membrane
... All cells are surrounded by a cell membrane (also called the plasma membrane). This is a biological membrane or biomembrane consisting of a double layer of lipids in which proteins are located. The cell membrane keeps the components of the cell isolated from the external environment. It also serves ...
... All cells are surrounded by a cell membrane (also called the plasma membrane). This is a biological membrane or biomembrane consisting of a double layer of lipids in which proteins are located. The cell membrane keeps the components of the cell isolated from the external environment. It also serves ...
Life: The Science of Biology, Ninth Edition
... action potentials in the sensory neuron. Bending in the other direction has the opposite effects. Thus, hair cells respond to the direction of motion as well as to its strength and speed. ...
... action potentials in the sensory neuron. Bending in the other direction has the opposite effects. Thus, hair cells respond to the direction of motion as well as to its strength and speed. ...
11-1 FUNCTIONS OF THE NERVOUS SYSTEM 1. Sensory input
... B. Voltage-gated ion channels open and close in response to small voltage changes across the plasma membrane. The small voltages are measured in units called millivolts. A millivolt (mV) is 1/1000 of a volt. This type of ion channel is important in the production of action potentials. C. Other gate ...
... B. Voltage-gated ion channels open and close in response to small voltage changes across the plasma membrane. The small voltages are measured in units called millivolts. A millivolt (mV) is 1/1000 of a volt. This type of ion channel is important in the production of action potentials. C. Other gate ...
Document
... Membrane Carriers or Pumps • Transmembrane proteins bind to solutes and transfer them across membrane • Pumps = carriers that consume ATP ...
... Membrane Carriers or Pumps • Transmembrane proteins bind to solutes and transfer them across membrane • Pumps = carriers that consume ATP ...
VI. The vertebrate nervous system is a hierarchy of structural and
... • As the electrical gradient increases, the negatively charged interior attracts K+ back into the cell. • If K+ was the only ion to cross the membrane, an equilibrium potential for potassium ions (= -85 mV) would be reached; this is the potential at which no net movement of K+ would occur since the ...
... • As the electrical gradient increases, the negatively charged interior attracts K+ back into the cell. • If K+ was the only ion to cross the membrane, an equilibrium potential for potassium ions (= -85 mV) would be reached; this is the potential at which no net movement of K+ would occur since the ...
Eukaryotic cell Plasma membrane
... 1- Separate the cell from the outside environment (they act as • barrier to isolate the cell from other environmental components). 2- Regulate the passage of materials and exchange of • molecules between the cell and outside environment. 3- Participate in many chemical reactions. They contain • enzy ...
... 1- Separate the cell from the outside environment (they act as • barrier to isolate the cell from other environmental components). 2- Regulate the passage of materials and exchange of • molecules between the cell and outside environment. 3- Participate in many chemical reactions. They contain • enzy ...
Osmosis
... solute concentration than that of another solution • Distilled water and tap water are hypotonic compared to blood. • Suppose a red blood cell is placed in water (hypotonic) the salt concentration of blood is greater than that of water. Therefore osmosis will take place. • Water moves into the cells ...
... solute concentration than that of another solution • Distilled water and tap water are hypotonic compared to blood. • Suppose a red blood cell is placed in water (hypotonic) the salt concentration of blood is greater than that of water. Therefore osmosis will take place. • Water moves into the cells ...
17-5 Working with Force, Field, Potential Energy, and
... (b) “What is the magnitude and direction of the net electric field at x = +5a?” Because the two charged particles create an electric field at all points around them, we can ask an infinite number of questions involving field – we have an infinite number of points to choose from. (c) “Consider the po ...
... (b) “What is the magnitude and direction of the net electric field at x = +5a?” Because the two charged particles create an electric field at all points around them, we can ask an infinite number of questions involving field – we have an infinite number of points to choose from. (c) “Consider the po ...
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.