Practice Question

1.Define the term active transport

Active transport moves substances from a more dilute solution to a more concentrated solution (against a concentration gradient).

2. Explain the difference between a dilute solution and a concentrated solution. 

A dilute solution has a low concentration of solute, high concentration of water. 

A concentrated solution has a high concentration of solute, low concentration of water.

3. Explain how active transport allows substances to move against a concetration gradient.

The cell membrane contains carrier proteins.

When the solute molecule enters the carrier protein, energy is used to change the shape of the carrier molecule, allowing the solute molecule to leave on the other side of the membrane.