Question

Which of the following is an example of active transport in cells?

• A. Osmosis
• B. Diffusion
• C. Sodium-potassium pump
• D. Facilitated diffusion

Hint:

Active transport requires energy, usually in the form of ATP, to move molecules against their concentration gradient, as seen in processes like the sodium-potassium pump.

Answer 1

The Correct Option is C

Active transport is the movement of substances across the cell membrane against their concentration gradient, requiring energy in the form of ATP.
- Option (1) is incorrect: Osmosis is a passive transport process where water moves from an area of low solute concentration to an area of high solute concentration. It does not require energy.
- Option (2) is incorrect: Diffusion is also a passive transport mechanism where particles move from an area of high concentration to low concentration. It does not require energy.
- Option (3) is correct: The sodium-potassium pump is a well-known example of active transport. It uses ATP to pump sodium ions out of the cell and potassium ions into the cell, against their concentration gradients.
- Option (4) is incorrect: Facilitated diffusion is a passive transport process where molecules move through a membrane protein from an area of high concentration to low concentration, without energy.
Thus, the sodium-potassium pump is an example of active transport.