Question

1. For the following transporters, please describe specifically how they contribute to establishing resting membrane potential making sure to include the direction of ion movement and the effect ion movement has on membrane potential. (3 pts; Shoot for 1-2 complete sentences for each transporter.)
   1. Na⁺/K⁺ pump:
   2. K⁺ leak channel:
   3. Na⁺ leak channel:

Answer 1

Ans. (a) the sodium - potassium pump(na+/k+) . In case ofothe resting membrane potential across the cell membrane, potassium & sodium gradient are established by moving sodium & potassium ion across the cell membrane is an active transport process involving the hydrolysis of ATP to provide energy .

Three Na+ transport outside the cell and transport of two K+ ions inside the cell.

It is active process , that is because there is already high concentration of Na+ outside & high concentration of K+ inside the cell.(2potassium inside & 3 sodium outside) this unbalanced charge transfer contribute to seperation of charge across the membrane . It is an important contributer to action potential produced by nerve cell.

(B) potassium leak channel is one of the major components that maintains the membrane potential in animal cell . The membrane potential is created by different in electrical charge on either side of a membrane.( From high conc. Towards lower conc.) With combined ion pumping and leakage of ion ,the cell can maintain a stable resting potential.

Two- pore domain potassium channel conduct leak or background potassium - selective current that are mostly time and voltage - independent . These channels play a role in setting the cell resting membrane potential & modulate cell responsiveness and excitability.

(C) sodium leak channel: na+ ions move across the cell membrane down their gradient (from high conc. Towards lower conc. ) With the combined ion pumping and leakage of ion ,the cell can maintain a stable resting membrane potential.

Leak channel are open in resting neuron and only open in response to a signal,ion channels. The channels extend from one side of plasma membrane to the other and have a tunnel through the middle.