During the depolarisation stage of an action potentialThe membrane potential returns to resting conditionsSodium (Na+) enters the cell down it's concentration gradientVoltage gated K+ channels are openPotassium (K+) enters the cell against its concentration gradient
Question
During the depolarisation stage of an action potentialThe membrane potential returns to resting conditionsSodium (Na+) enters the cell down it's concentration gradientVoltage gated K+ channels are openPotassium (K+) enters the cell against its concentration gradient
Solution
The statement seems to be a mix of different stages of an action potential. Let's break it down:
-
"During the depolarisation stage of an action potential" - This is the first phase of an action potential where the neuron is activated. The membrane potential rapidly moves from negative to positive.
-
"The membrane potential returns to resting conditions" - This is not correct. During depolarization, the membrane potential does not return to resting conditions. It actually becomes more positive due to the influx of sodium ions.
-
"Sodium (Na+) enters the cell down it's concentration gradient" - This is correct. During depolarization, voltage-gated sodium channels open, allowing sodium ions to flow into the neuron. This influx of positive ions makes the inside of the neuron more positive, causing depolarization.
-
"Voltage gated K+ channels are open" - This is not correct. During depolarization, the voltage-gated potassium channels are typically closed. They open during the repolarization phase, which follows depolarization.
-
"Potassium (K+) enters the cell against its concentration gradient" - This is not correct. Potassium ions do not enter the cell during depolarization. Instead, they exit the cell during the repolarization phase, moving down their concentration gradient (from inside the cell where they are high in concentration, to outside the cell where they are low in concentration).
Similar Questions
A recently depolarized area of a cell membrane cannot generate an action potential because of theMultiple Choiceabsolute refractory period.high concentration of sodium ions in the extracellular fluid.the high concentration of potassium ions in the cytoplasm.presence of receptor sites on the membrane.
The charge difference across an unstimulated cell, called the Blank______ potential, can be attributed to the potassium and sodium concentrations inside and outside of the cell.Multiple choice question.action potentialresting membranedepolarizing potentialgraded potentialNeed help? Review these concept resource
Resting membrane potential:Is the process by which cells communicateResults in the outside of the cell having a -70mV polarity relative to the inside.Is maintained by the sodium/potassium ATPase pump continuously pumping Na+ into the cellResults in high concentrations of Na+ on the outside of the cell
Depolarization of a cell membrane occurs becauseMultiple ChoiceSodium ions are blocked from entering the cellMore sodium ions diffuse into the cell than potassium ions diffuse out of itThe concentration of sodium and potassium ions in the extracellular fluid is at equilibriumThe concentration of sodium and potassium ions in the cell is at equilibrium
Depolarization occurs becauseMultiple Choicepotassium ions continue to diffuse out of the cell after the inactivation gates of the voltage-gated sodium ion channels begin to close.more sodium ions diffuse into the cell than potassium ions diffuse out of it.the extra efflux of potassium ions causes the membrane potential to become slightly more positive than the resting value.the increased potassium ion permeability lasts slightly longer than the time required to bring the membrane potential back to its resting level.the inactivation gates of the voltage-gated sodium ion channels begin to open, and the diffusion of sodium ions decreases.
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.