Cell BiologyComparison

Diffusion vs Osmosis vs Active Transport: Side-by-Side

Part of Cell Transport · GCSE GCSE Biology revision

This comparison covers Diffusion vs Osmosis vs Active Transport: Side-by-Side within Cell Transport for GCSE Biology. Diffusion, osmosis, active transport, factors affecting transport, surface area to volume ratio, and practical investigations It is section 11 of 19 in this topic. Use this comparison to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 11 of 19

Practice

23 questions

Recall

20 flashcards

⚖️ Diffusion vs Osmosis vs Active Transport: Side-by-Side

Visual comparison of diffusion, osmosis and active transport showing particle movement across membranes, with a carrier protein and energy in active transport

Figure: Comparing the three types of cell transport

Feature	Diffusion	Osmosis	Active Transport
What moves?	Any particles (gases, ions, small molecules)	Water molecules only	Specific molecules / ions (e.g. glucose, mineral ions)
Direction	High → Low concentration (down gradient)	Dilute → Concentrated (down water concentration gradient)	Low → High concentration (AGAINST gradient)
Energy required?	No — passive	No — passive	Yes — ATP from mitochondria
Membrane needed?	Not necessarily (can occur in air/water)	Yes — must be partially permeable	Yes — uses protein carrier molecules in membrane
Concentration gradient?	Required (high to low)	Required (low water concentration pulls water in)	Works against gradient
Body examples	O2 into blood at alveoli; CO2 out of cells	Water into root hair cells from soil; water reabsorption in kidneys	Glucose absorption in small intestine; mineral ions into root hair cells from soil
Plant examples	CO2 into leaf cells for photosynthesis	Water entering root cells from soil	Mineral ions (nitrate, phosphate) into root hair cells

Keep building this topic

Read this section alongside the surrounding pages in Cell Transport. That gives you the full topic sequence instead of a single isolated revision point.

Why Does Active Transport Require Energy?Key Terms: Cell Transport The Cell's Transport System Cell Transport — Tap to Explore the 3 Mechanisms

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).

23 questions on Cell Transport — practise free

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Why Does Active Transport Require Energy?

Key Terms: Cell Transport