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, typically in the form of ATP. This process is essential for maintaining cellular homeostasis and function.

5 Must Know Facts For Your Next Test

1. Active transport requires energy input, usually derived from ATP.
2. It involves carrier proteins known as pumps that are specific to the substances being transported.
3. The sodium-potassium pump is a well-known example that helps maintain cell potential by moving sodium out and potassium into the cell.
4. Active transport is crucial for nutrient uptake, waste removal, and maintaining ion gradients across membranes.
5. There are two main types of active transport: primary (direct use of ATP) and secondary (indirect use of energy).

Review Questions

• What form of energy is most commonly used in active transport?
• Name an example of a carrier protein involved in active transport and its function.
• How does active transport differ from passive transport?

Related terms

Passive Transport: The movement of molecules across a cell membrane without the use of energy, moving from high to low concentration.

ATP (Adenosine Triphosphate): A molecule that provides energy for cellular processes including active transport.

Sodium-Potassium Pump: A type of carrier protein that uses ATP to move sodium ions out and potassium ions into the cell against their concentration gradients.