How the sodium potasium pump works

Overview

The sodium-potassium pump is a vital membrane protein that actively transports sodium (Na+) out of the cell and potassium (K+) into the cell, maintaining the essential electrochemical gradient across the plasma membrane. This pump operates through a process known as active transport, which requires energy in the form of ATP. For every three sodium ions expelled from the cell, two potassium ions are imported, resulting in a net negative charge inside the cell. This gradient is crucial for various cellular functions, including nerve impulse transmission and muscle contraction, as it helps regulate cell volume and maintain resting membrane potential.

Questions and Answers

  1. What is the primary function of the sodium-potassium pump?

    The primary function of the sodium-potassium pump is to maintain the electrochemical gradient across the plasma membrane by actively transporting sodium ions out of the cell and potassium ions into the cell.

  2. How many sodium ions are transported out of the cell for every cycle of the pump?

    For every cycle of the sodium-potassium pump, three sodium ions are transported out of the cell.

  3. How many potassium ions are transported into the cell during one cycle of the pump?

    Two potassium ions are transported into the cell for every cycle of the sodium-potassium pump.

  4. What type of transport mechanism does the sodium-potassium pump utilize?

    The sodium-potassium pump utilizes active transport, which requires energy in the form of ATP to function.

  5. What is the net charge effect of the sodium-potassium pump on the cell?

    The sodium-potassium pump results in a net negative charge inside the cell because it exports three positively charged sodium ions while importing only two positively charged potassium ions.

Multiple-Choice Questions

  1. What is the main function of the sodium-potassium pump?

    a) To transport glucose into the cell
    b) To maintain the electrochemical gradient
    c) To synthesize proteins
    d) To facilitate cell division
    Answer: b) To maintain the electrochemical gradient

  2. How many sodium ions are pumped out of the cell during one cycle of the sodium-potassium pump?

    a) 1
    b) 2
    c) 3
    d) 4
    Answer: c) 3

  3. How many potassium ions are transported into the cell for each cycle of the pump?

    a) 1
    b) 2
    c) 3
    d) 4
    Answer: b) 2

  4. What type of transport mechanism does the sodium-potassium pump utilize?

    a) Passive transport
    b) Facilitated diffusion
    c) Active transport
    d) Simple diffusion
    Answer: c) Active transport

  5. What is the source of energy for the sodium-potassium pump?

    a) Glucose
    b) ATP
    c) NADH
    d) FADH2
    Answer: b) ATP