Biology IGCSE Edexcel - Diffusion, Osmosis, and Active Transport

What is diffusion?

Movement of particles from high concentration → low concentration (no energy needed).

What is osmosis?

The diffusion of water across a partially-permeable membrane, from a region of high water concentration → low water concentration. Only water molecules move through this.

What is active transsport?

Movement of particles from a region of low concentration → a region of high concentration (against the concentration gradient), using energy from respiration.

How does the temperature affect the speed of particles?

Higher temperatures make particles move faster, speeding up diffusion

What is Plasmolysis?

When a plant cell loses water and the cytoplasm shrinks away from the cell wall.

What is a partially permeable membrane?

A membrane that allows some molecules (like water) to pass through but not others.