Answer :-
a). Depolarization :- The depolarisation process begins with a stimulus. Simple touch, light, foreign particle or even electrical stimulus can be this stimuli. This stimulation causes the cell to change in voltage. This initial change in stress triggers the opening of sodium and calcium channels within the cell membrane.
b). Repolarization :- Voltage-gated potassium channels have K+-selective pores formed by membranedepolarization. This opening allows K+ ions to travel across the plasma membrane and produce K+ currents that appear to repolarize the membrane towards K+ (EK) equilibrium potential.The transition from depolarization to repolarization depends on the kinetic mechanisms of both K+ and Na+ channels gated by voltage. Although both Na+ and K+ voltage gated channels activate at approximately the same voltage (-50 mV), Na+ channels have faster kinetics and turn on / off much faster.Repolarization occurs as the influx of Na+ decreases (channels disinactivate) and as its channels expand, the efflux of K+ ions increases.
C). Restoring ion concentration:- The voltage-gated potassium channels remain open a little longer than is required to return the membrane to its ability of rest. It results in an effect of "undershooting," in which the membrane potential dips slightly lower (more negative) than its resting potential. The voltage-gated potassium channels eventually close, and the membrane future stabilizes at resting future. The sodium channels return to their normal state (remaining closed but once again becoming voltage responsive). The potential process of operation can then begin again.
ana ion channels. The two ions in questions are Na+ (sodium ion) and K+ (potassium ion)....
Question 4 2 pts During and action potential, sodium (Na+) rushes into the cell causing of the cell. Then sodium channels close and potassium (K+) rushes out of the cell, causing of the cell. However, the potassium overshoots and causes Question 5 2 pts During the refractory period, the pumps Na+ ions out of the cell and K+ions into the cell, re-establishing the resting membrane potential and concentration gradient. Serotonin Acetylcholine Glutamate Endorphins Barbiturates GABA Dopamine Cocaine Sodium Potassium Calcium...
choices for A: Na+/K+ pumps, voltage gated K+ channels, voltage gated Ca+ channels, voltage gated Na+ channels choices for B: bidirectionally, unidirectionally choices for C: Na+/K+ pumps, voltage gated K+ channels, voltage gated Ca+ channels, voltage gated Na+ channels choices for D: Na+/K+ pumps, voltage gated K+ channels, voltage gated Ca+ channels, voltage gated Na+ channels Consider this graph illustrating the generation of an action potential across the plasma membrane of a stimulated neuron. +40 ACTION POTENTIAL plasma membrane potential...
For each phase of an action potential, indicate the ion channel most responsible for the membrane potential change that occurs during the phase. Action Potential Phases Ion Channels Depolarization phase Repolarization phase Hyperpolarization phase Voltage-gated potassium channels Chemically-gated sodium channels Chemically-gated potassium channels Voltage-gated sodium channels
An ion channel inhibitor is discovered which selectively targets potassium ion voltage-gated channels. Which of the following effects would this inhibitor most likely have on neurons? and here are the answer choices, A. Decrease in the sensitivity of action potential generation B. Increase of the resting potential of the cell to 0 mV C. Inhibition of repolarization after an action potential D. Inhibition of action potential depolarization
29 From the following graph, which channels/pumps are open/active at position 4? Mark all that apply A. Na+/K+ Pump B. Voltage gated Na+ Channel C. Voltage gated K+ Channel D. Passive K+ channel E. None of the pump/channels are open/active Membrane potential (m)
How does facilitated diffusion differ from simple diffusion? Facilitated diffusion requires ATP Facilitated diffusion requires a solute-specific protein carrier Facilitated diffusion transports solute against its’ concentration gradient Which of the following is TRUE about primary active cell membrane transport? It is a form of transport that requires a protein “pump” It is a form of transport that transports ions and/or solute against their concentration gradient It is a transport mechanism that requires energy released from the splitting of ATP by...
Q2. The Na+/K+ pump and voltage gated K+ channels both transport K+ across the membrane. A) Compare and contrast these two mechanisms for K+ transport indicating important functional and structural differences. B) Describe the process for putting a voltage gated K+ channel in the membrane starting at the ribosome and ending at the plasma membrane.
The sodium-potassium pump (aka Na-K ATPase) a.pumps Na out of and K* into the cell b. pumps Na* and K* out of the cell pumps Na* and K* into the cell d. pumps Na into and K* out of the cell
In its resting state, the membrane surrounding a neuron is permeable to potassium ions but only slightly permeable to sodium ions. Thus, positive K ions can flow through the membrane in an attempt to equalize K concentration, but Na ions cannot as quickly. This leads to an excess of Na ions outside of the cell. If the space outside the cell is defined as zero electric potential, then the electric potential of the interior of the cell is negative. This...
How would you alter sodium and/or potassium voltage-gated channels to preserve their dependence on voltage, but eliminate action potentials? Effect of altering Na/K channels