Question

Depolarization of a membrane can be induced by ________. Group of answer choices increasing its membrane's permeability to Na decreasing its membrane's permeability to H

Answer 1

Answer: Increasing its membrane's permeability to Na

Explanation:

Depolarisation is a decrease in the absolute value of the membrane potential in a neuron. The membrane potential of a neuron at rest is normally negative in the intracellular area (-70 mV). This negative potential is generated by the presence on the membrane of:

• Sodium/potassium pumps, which actively extract 3 Na+ (sodium) ions from the inside to the outside of the cell and introduce 2 K+ (potassium) ions, consuming 1 molecule of ATP.
• Potassium channels which allow free exchange of K+ ions.
• Cl- pumps, which actively extract chlorine.

As a result, the outside of the cell is richer in Na+ and Cl- than the inside, while K+ ions accumulate on the inside with respect to the outside. The net charge balance is negative because 3 Na+ ions are released for every 2 K+ ions and also, because of the presence of negatively charged molecules in the interior of the cell such as ATP and proteins.

When a neuron receives a stimulus, the sodium channels present in the membrane are opened, and therefore Na+ enters the cell in favour of the concentration gradient, so that the membrane potential changes to positive by means of ion exchange, producing depolarisation. If the depolarization reaches a certain threshold value, an action potential is generated. The next step is the opening of the potassium channels and the inactivation of the sodium channels, so that the repolarization of the membrane takes place. The sodium channels, will return to the closed state in the hyperpolarization to continue in this state during all the rest potential; until the arrival of a new action potential which produces the activation and opening of the sodium channels, repeating the cycle again and generating a new depolarizing action. This process is part of the synaptic transmission.

Answer 2

Answer: Increasing it's membrane permeability by Na.

Explanation:

Membrane depolarization occur in the cells are refer to a change or shift in electric charge within the cell which lead to reduction in negative charge in the cell. It is important in cell function and communication between cell.

When the membrane potential increase, sodium ion channels are opened which allow the ions to enter freely, as the flow of sodium ion increase, the concentration of positively charged cations in the cells cause depolarization thereby causing less negative charge in the cell.