Transport
... B Molecules tend to move down their concentration gradients (ie. from higher concentration to lower concentration) D The cell membrane helps maintain homeostasis C Ion channels help ions move across the cell membrane A Glucose often enters the cell by facilitated diffusion using carrier molecules. C ...
... B Molecules tend to move down their concentration gradients (ie. from higher concentration to lower concentration) D The cell membrane helps maintain homeostasis C Ion channels help ions move across the cell membrane A Glucose often enters the cell by facilitated diffusion using carrier molecules. C ...
Chemical Signals in Animals
... which proteins are made after reception of the signal molecule(s)? Compare and contrast receptor enzymes and G-protein-linked reception and transduction of extracellular chemical messages? ...
... which proteins are made after reception of the signal molecule(s)? Compare and contrast receptor enzymes and G-protein-linked reception and transduction of extracellular chemical messages? ...
Electrical Communication #2
... Think of the axon like a fuse: when you light a fuse, the end heats up the next segment, which flares up and heats up the following segment, which then flares up. Unlike a piece of string, a fuse carries the flame all the way down to the other end. ...
... Think of the axon like a fuse: when you light a fuse, the end heats up the next segment, which flares up and heats up the following segment, which then flares up. Unlike a piece of string, a fuse carries the flame all the way down to the other end. ...
7-Nerves - bloodhounds Incorporated
... The more positive the voltage, due to Na+ diffusing into the cell, the more Na+ gates open. This creates a more positive voltage and more Na+ gates open ...
... The more positive the voltage, due to Na+ diffusing into the cell, the more Na+ gates open. This creates a more positive voltage and more Na+ gates open ...
Created by Tiarra Moore Crawford Long Middle School Atlanta, GA
... How can substances move into and out of a cell? Diffusion The process by which molecules move from an area of higher concentration to an area of lower concentration. Concentration = the amount of a substance in a given volume. ...
... How can substances move into and out of a cell? Diffusion The process by which molecules move from an area of higher concentration to an area of lower concentration. Concentration = the amount of a substance in a given volume. ...
Structure of an iron-transport protein revealed
... For the first time, the three dimensional structure of but not with Ca2+", explains Ehrnstorfer. The study the protein that is essential for iron import into also shows that mutations in the binding site cells, has been elucidated. Biochemists of the weaken ion binding and transport in both the Univ ...
... For the first time, the three dimensional structure of but not with Ca2+", explains Ehrnstorfer. The study the protein that is essential for iron import into also shows that mutations in the binding site cells, has been elucidated. Biochemists of the weaken ion binding and transport in both the Univ ...
Neuron Structure and Function
... Channels of an Action potentials Voltage gated Na+ channels: 3 states: closed, open, inactive Closed to open: - Depolarization is necessary to open the channel - Acts to activate itself in a regenerative cycle - More Na+ influx depolarizes the membrane which opens more channels which depolarizes th ...
... Channels of an Action potentials Voltage gated Na+ channels: 3 states: closed, open, inactive Closed to open: - Depolarization is necessary to open the channel - Acts to activate itself in a regenerative cycle - More Na+ influx depolarizes the membrane which opens more channels which depolarizes th ...
Previously on Bio308
... Why might these things pose problems? How does the body get around those problems? ...
... Why might these things pose problems? How does the body get around those problems? ...
Active Transport vs. Passive Transport both processes move things
... Exocytosis: moves things out of cells by putting substance into vesicle the vesicle moves to cell membrane, fuses with cell membrane, is released to outside of cell these items are moved by bulk transport because they are too large to get in and out of the cell by diffusion examples are proteins, ho ...
... Exocytosis: moves things out of cells by putting substance into vesicle the vesicle moves to cell membrane, fuses with cell membrane, is released to outside of cell these items are moved by bulk transport because they are too large to get in and out of the cell by diffusion examples are proteins, ho ...
ap biology
... 1. Given an animal cell with pressure = 0, solute potential = -2, and a solution surrounding the cell with pressure = 0, and solute potential = 0. The cell membrane is permeable to both water and solute. a. Solute concentration is initially higher here: ________________ b. Water potential is initial ...
... 1. Given an animal cell with pressure = 0, solute potential = -2, and a solution surrounding the cell with pressure = 0, and solute potential = 0. The cell membrane is permeable to both water and solute. a. Solute concentration is initially higher here: ________________ b. Water potential is initial ...
Recording Action Potentials from Cockroach Mechanoreceptors
... to the resting level. Often, however, a neurophysiologist does not need to know the actual changes in the membrane potential, but only when an action potential occurs. In this case, an extracellular recording is usually adequate. Electrodes are placed outside a neuron to record the electrical potent ...
... to the resting level. Often, however, a neurophysiologist does not need to know the actual changes in the membrane potential, but only when an action potential occurs. In this case, an extracellular recording is usually adequate. Electrodes are placed outside a neuron to record the electrical potent ...
File
... Endocytosis is the process in which cells bring in a large molecule from outside the cell. A pocket forms on the cell membrane around a large molecule, which then pinches off and brings a large molecule into the cell, using a vesicle formed from the membrane. Exocytosis is the process cells use to e ...
... Endocytosis is the process in which cells bring in a large molecule from outside the cell. A pocket forms on the cell membrane around a large molecule, which then pinches off and brings a large molecule into the cell, using a vesicle formed from the membrane. Exocytosis is the process cells use to e ...
Cell types: Muscle cell Adipocyte Liver cell Pancreatic cell Example
... millisecond, then the membrane potential is rapidly restored to its resting negative value (repolarization). These events are controlled by the brief opening and closing of a transient, voltageactivated sodium channel and then the opening of the delayed rectifyer potassium channel and later other p ...
... millisecond, then the membrane potential is rapidly restored to its resting negative value (repolarization). These events are controlled by the brief opening and closing of a transient, voltageactivated sodium channel and then the opening of the delayed rectifyer potassium channel and later other p ...
VOCAB Chapter 7
... Process that REQUIRES ENERGY to move molecules across a cell membrane against a concentration gradient (moves molecules from lower concentration → higher concentration) PASSIVE TRANSPORT: Process that moves molecules across a cell membrane WITHOUT USING ENERGY DIFFUSION: Process by which molecules t ...
... Process that REQUIRES ENERGY to move molecules across a cell membrane against a concentration gradient (moves molecules from lower concentration → higher concentration) PASSIVE TRANSPORT: Process that moves molecules across a cell membrane WITHOUT USING ENERGY DIFFUSION: Process by which molecules t ...
Mapping the Body.indd
... Oxygen and carbon dioxide are small and are non-polar so they can use simple diffusion, too. They are very numerous and must get across quickly, so it is good that they can just cross on their own. If they had to wait for a molecular gate to open, this would cause a chemical traffic jam for sure! ...
... Oxygen and carbon dioxide are small and are non-polar so they can use simple diffusion, too. They are very numerous and must get across quickly, so it is good that they can just cross on their own. If they had to wait for a molecular gate to open, this would cause a chemical traffic jam for sure! ...
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.