Active transport

Definition

Active transport is the movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration, using energy in the form of ATP. This process is essential for maintaining cellular homeostasis and functions.

5 Must Know Facts For Your Next Test

1. Active transport requires energy input, usually in the form of ATP.
2. It moves molecules against their concentration gradient.
3. The sodium-potassium pump is a classic example of active transport in cells.
4. Active transport is crucial for nutrient uptake in gut epithelial cells.
5. Compared to passive transport, active transport allows cells to maintain higher concentrations of certain substances.

Review Questions

• What type of energy is required for active transport?
• How does active transport differ from passive transport?
• Give an example of an active transport mechanism found in human cells.

Related terms

Diffusion:

The passive movement of molecules or particles from an area of higher concentration to an area of lower concentration.

Osmosis:

The diffusion of water through a selectively permeable membrane from a region of lower solute concentration to a region of higher solute concentration.

Sodium-Potassium Pump:

A type of active transport where sodium ions are pumped out and potassium ions are pumped into the cell against their respective concentration gradients using ATP.