This definitions covers Understanding Concentration Terms within Cell Transport for GCSE Biology. Diffusion, osmosis, active transport, factors affecting transport, surface area to volume ratio, and practical investigations It is section 9 of 19 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.

📖 Understanding Concentration Terms

🔼 Hypertonic Solution

Higher solute concentration than the cell

Effect: Water moves OUT of cell

Example: 1% salt solution vs potato cells

🔽 Hypotonic Solution

Lower solute concentration than the cell

Effect: Water moves INTO cell

Example: Distilled water vs potato cells

➡️ Isotonic Solution

Same solute concentration as the cell

Effect: No net water movement

Example: ~0.5% salt solution vs potato cells

Practice questions for Cell Transport

Which statement best describes diffusion?

A. The movement of particles from a region of low concentration to high concentration
B. The net movement of particles from a region of high concentration to low concentration
C. The movement of water molecules through a partially permeable membrane
D. The movement of particles using energy from respiration

1 markfoundation

Explain how osmosis causes a plant cell to become plasmolysed when placed in a concentrated sugar solution.

3 marksstandard

Quick recall flashcards

Define osmosis

The movement of water molecules from an area of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration) through a semi-permeable membrane.

Define diffusion

The movement of particles from an area of high concentration to an area of low concentration down a concentration gradient. No energy is required (passive process).

Understanding Concentration Terms