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Why does increasing extracellular potassium ion cause membrane potential to change to a less negative value?
the membrane potential became less negative because less potassium ions went out of the cell (since the extra cellular space has higher concentration of potassium, and potassium goes down its concentration gradient, from high concentration to low concentration). since less potassium (K+)which is positive, left the cell more it became more positive (less negative)
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Why does increasing the extracellular K cause the membrane potential to change?
Increasing extracellular potassium concentration can depolarize the cell membrane potential because potassium ions are leaking out of the cell less efficiently, leading to an accumulation of positive charge outside the cell. This disrupts the normal balance of ions and can make it easier for the cell to depolarize and generate an action potential.
What effect will Raising the potassium ion concentration in the extracellular fluid surrounding a nerve cell have?
Increasing the potassium ion concentration in the extracellular fluid surrounding a nerve cell can lead to a decrease in the resting membrane potential and make it more positive. This can result in a decrease in the ability of the nerve cell to generate an action potential and effectively transmit signals. Ultimately, higher extracellular potassium levels can impair nerve cell function.
Why increasing extracellular potassium ion reduces the net diffusion of potassium ion out of neuron through the potassium leak channel?
Increasing extracellular potassium ion concentration will create a smaller concentration gradient across the cell membrane, making it less favorable for potassium ions to move out of the neuron through the leak channels. The leak channels are gated by both membrane voltage and concentration gradients, so alterations in extracellular potassium levels can impact the electrochemical equilibrium that regulates potassium movement. Ultimately, this can result in a reduced net diffusion of potassium ions out of the neuron.
Explain why a change in extracellular sodium did not alter the membrane potential in the resting neuron?
A change in extracellular sodium concentration would not alter the resting membrane potential of a neuron because the resting potential is primarily determined by the relative concentrations of sodium and potassium ions inside and outside the cell, as mediated by the sodium-potassium pump and leak channels. Changes in extracellular sodium concentration would not directly affect this equilibrium.
Does an increase or decrease in potassium extracellular ions hyperpolarize a cell?
An increase in extracellular potassium ions typically depolarizes a cell, while a decrease in extracellular potassium ions can hyperpolarize a cell. This is due to the role of potassium ions in influencing the membrane potential of cells.
What effect does the opening of the potassium channels have on the charge difference across the neuron's membrane?
Opening of potassium channels allows potassium ions to move out of the neuron, leading to hyperpolarization by increasing the negative charge inside the neuron. This action increases the charge difference across the membrane, known as the resting membrane potential, making the neuron less likely to fire an action potential.
The role of the sodium potassium pump in maintaining a cells resting membrane potential?
The sodium-potassium pump helps maintain the resting membrane potential by actively pumping sodium ions out of the cell and potassium ions into the cell against their concentration gradients. This creates an electrochemical gradient that contributes to the negative resting membrane potential inside the cell. The pump is crucial for regulating cell volume, establishing the resting membrane potential, and supporting the action potentials required for cellular communication.
Through the membrane of a resting neuron highly permeable to potassium ions its membrane potential does not exactly match the equilibrium potential for potassium because the neuronal membrane is?
The neuronal membrane also has ion channels for other ions besides potassium, such as sodium or chloride, that can influence the resting membrane potential. These other ions contribute to the overall equilibrium potential of the neuron, which affects its resting membrane potential. Additionally, the activity of Na+/K+ pumps helps establish and maintain the resting membrane potential, contributing to the slight difference from the potassium equilibrium potential.
Why is there a resting membrane potential across the cell membrane?
sodium/potassium pump
Why resting membrane potential value sodium is closer to equilibrium of potassium?
The resting membrane potential value for sodium is closer to the equilibrium of potassium because the sodium-potassium pump actively maintains a higher concentration of potassium inside the cell and a higher concentration of sodium outside the cell. This leads to a higher permeability of potassium ions at rest, resulting in the resting membrane potential being closer to the equilibrium potential of potassium.
The membrane-bound enzyme system that restores and maintains the resting membrane potential is what pump?
The membrane-bound enzyme system responsible for restoring and maintaining the resting membrane potential is the sodium-potassium pump. It actively transports sodium ions out of the cell and potassium ions into the cell against their concentration gradients to establish the resting membrane potential.
Most diffusable ion in memebrane potential is?
Potassium ions are the most diffusible ion in the membrane potential because of the presence of leak channels that allow potassium to move easily across the membrane. This creates a concentration gradient that drives the movement of potassium ions into and out of the cell to establish the resting membrane potential.
