Summary
Active transport is the movement of substances across cell membranes using energy from ATP.
- Active Transport — movement of molecules against a concentration gradient using energy. Example: Uptake of glucose in the intestines.
- ATP (Adenosine Triphosphate) — energy currency of the cell used in active transport. Example: Provides energy for sodium-potassium pump.
- Concentration Gradient — difference in concentration of a substance across a space. Example: Higher concentration of ions outside the cell than inside.
Exam Tips
Key Definitions to Remember
- Active Transport: movement of molecules against a concentration gradient using energy.
- ATP: energy currency of the cell used in active transport.
- Concentration Gradient: difference in concentration of a substance across a space.
Common Confusions
- Confusing active transport with passive transport, which does not require energy.
- Misunderstanding that active transport moves substances from low to high concentration.
Typical Exam Questions
- What is active transport? Movement of molecules against a concentration gradient using energy.
- How does ATP provide energy for active transport? ATP releases energy when it is converted to ADP.
- Why is active transport important in cells? It allows cells to take in nutrients and expel waste against concentration gradients.
What Examiners Usually Test
- Understanding of how active transport differs from passive transport.
- The role of ATP in active transport.
- Examples of active transport in biological systems.