Term
| T/F ion channels are not selective which is needed for membrane potential. |
|
Definition
false
ion channels ARE selective |
|
|
Term
| what range is the resting membrane potential? |
|
Definition
|
|
Term
| what ion is in high concentration on the inside of the cell? |
|
Definition
|
|
Term
| what ions are in high concentration outside the cell? |
|
Definition
|
|
Term
| what can we not have without membrane potential? |
|
Definition
|
|
Term
| when is voltage established? |
|
Definition
| when the membrane has permeability to one or more ions |
|
|
Term
| in relation to the membrane potential what do ion channels do? |
|
Definition
| allow ions to move across the membrane down their concentration gradients |
|
|
Term
| in most cases, what ion determines the resting membrane potential? |
|
Definition
|
|
Term
| what are the two basic functions of membrane potential? |
|
Definition
1-allows the cell to function as a battery
2-to transmit signals between different parts of a cell |
|
|
Term
| explain the function of allowing the cell to be a battery |
|
Definition
| providing power to operate many molecular devices embedded in the membrane |
|
|
Term
| what initiates the departure from RMP? |
|
Definition
| the opening and closing of ion channels |
|
|
Term
| what is resting membrane potential (RMP)? |
|
Definition
| the voltage difference existing between two sides of a semipermeable membrane of any cell |
|
|
Term
| what is needed for the cell to be conductive? |
|
Definition
|
|
Term
| T/F the outside of the cell is more negative than the inside. |
|
Definition
|
|
Term
|
Definition
| by inserting micro electrodes through the membrane into the cytosol and compare the voltage to the outside the cell |
|
|
Term
| what is the Nernst equation used for? |
|
Definition
| used to calculate the voltage of an electrochemical cell or to find the concentration of one of the components of the cell |
|
|
Term
| what is Nernst potential? |
|
Definition
| the voltage which would balance out the unequal concentration across the membrane |
|
|
Term
| What rule is to be remembered that involves the Nernst potential? |
|
Definition
| When the membrane conductance increase for a particular ion the membrane potential will move toward the Nernst potential for the ion. |
|
|
Term
| what two factors establish the MP? |
|
Definition
electrical force
diffusion |
|
|
Term
| what is electrical force? |
|
Definition
| the mutual attraction between particles with opposite electrical charges |
|
|
Term
|
Definition
| tendency for particles to redistribute from regions where they are highly concentrated to regions where the concentration is low |
|
|
Term
| what three key factors influence MP? |
|
Definition
1-high concentration of electrically charged particles on either side of the membrane
2-channel proteins: a way for the ions to be moved through the membrane
3-mechanism for those ions to be maintained on either side of the membrane (Na-K pumps) |
|
|
Term
what are potassium leak channels?
what do these leak channels establish? |
|
Definition
channels embedded in the neuron membrane that allow K to freely move in and out of the cell
an electrical imbalance |
|
|
Term
| a sodium potassium pump allows how many Na ions in and K ions out? |
|
Definition
|
|
Term
| explain the disruption of the RMP when you step on a tack. |
|
Definition
1-step on the tack
2-depolarization occurs (disruption) and conducted along the axon (Na channels allow for depolarization |
|
|
Term
|
Definition
the current through a conductor between two points is directly proportional to the potential difference across the two points and inversely proportional to the resistance
Voltage = I(current)Resistance |
|
|
Term
| what is electrical conductance? |
|
Definition
| the relative ability of an electrical charge to migrate from one point to another |
|
|
Term
| what does conductance depend on? |
|
Definition
the number of particle (hopefully high)
need a way to move across the membrane |
|
|
Term
| what mediates the change in membrane potential? |
|
Definition
|
|
Term
| name the three different types of channels. |
|
Definition
voltage gated
ligand gated
mechanically gated |
|
|
Term
| T/F as many as 100 million ions can flow through a single channel. |
|
Definition
|
|
Term
| T/F any ion can pass through any channel. |
|
Definition
false
channels are very selective only allowing on or a few ions to pass |
|
|
Term
what is an integral membrane protein?
what integral membrane protein is most important to note for our study? |
|
Definition
assembly of several proteins in a circular arrangement of identical proteins closely packed around a water filled pore through the pain of the membrane
sodium-potassium pump |
|
|
Term
does is the
primary level
secondary level
tertiary level
quaternary level
of protein formation? |
|
Definition
primary-sequence of amino acids
secondary-coiling of peptides
tertiary-3D folding
quaternary-polypeptides bind together to make a larger protein |
|
|
Term
| what is the basic structural components of an amino acid? |
|
Definition
hydrogen
amine group
carboxyl group
R group |
|
|
Term
| what is the importance of the making of proteins for the nervous system in response to exercise? |
|
Definition
| to make more channels or receptors to be more efficient |
|
|
Term
voltage gated ions channels open and close in response to what?
give an example. |
|
Definition
a change in voltage within the cell
voltage gated calcium channels in the terminal branch |
|
|
Term
ligand gated ion channels open and close in response to what?
give an example. |
|
Definition
the binding of neurotransmitters or ions to specific binding sites of the outside of the channel protein
Sodium channels on the post-synaptc cell membrane |
|
|
Term
| what is the primary neurotransmitter for muscle? |
|
Definition
|
|
Term
mechanically gated ion channels open and close in response to what?
give an example. |
|
Definition
movement of receptors causes the gate to open and close
movement of the cilia triggers the SNARE complex to form |
|
|
Term
| what are the three main types of transport across the cell membrane? |
|
Definition
simple diffusion
facilitated diffusion
active transport |
|
|
Term
| what are the two types of structures that play the largest role in the depolarization of the cell? |
|
Definition
| ion channels and ion pumps |
|
|
Term
| what percent of energy in the CNS goes to maintaining the MP by sodium potassium pumps? |
|
Definition
|
|
Term
| what is the basis of the evolution of neural transmission? |
|
Definition
| sodium-potassium pumps and the evolution of voltage-gated channels |
|
|
Term
| what is the action of the sodium-potassium pump? |
|
Definition
|
|
Term
| outline the calcium pump. |
|
Definition
| enzymes that transports Ca++ out of the cytosol and across the membrane, that is activated by a change in voltage on the inside of the cell |
|
|
Term
| why is the sodium-potassium pump important for life? |
|
Definition
| K+ leaks out of the cell causing the inside of the cell to become more negative. The sodium-potassium pump, pumps K+ back into the cell to maintain the MP. without this a hyper polarization would occur as a result of too much K+, resulting in a cell that is not in position to depolarize and conductivity ceases. |
|
|
Term
| T/F if you are unable to manage K+ levels in the body you'll die. |
|
Definition
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