Study Notes
Diffusion is a type of passive transport where molecules move from an area of higher concentration to an area of lower concentration without the use of energy.
- Diffusion — movement of particles from high to low concentration Example: Oxygen moving into cells or flavour molecules from a tea bag spreading in hot water.
- Passive Transport — transport that does not require energy Example: Diffusion of oxygen into cells.
- Active Transport — transport that requires energy Example: Sodium ions being pumped out of a cell.
Exam Tips
Key Definitions to Remember
- Diffusion: Movement of particles from an area of high concentration to an area of low concentration.
- Passive Transport: Movement of substances across cell membranes without energy.
- Active Transport: Movement of substances across cell membranes using energy.
Common Confusions
- Confusing passive transport with active transport.
- Thinking diffusion requires energy.
Typical Exam Questions
- What is diffusion? Movement of particles from high to low concentration without energy.
- How does passive transport differ from active transport? Passive transport does not require energy, while active transport does.
- Give an example of diffusion in everyday life? Flavour molecules spreading from a tea bag in hot water.
What Examiners Usually Test
- Understanding of diffusion as a passive process.
- Differences between passive and active transport.
- Examples of diffusion in biological systems.