Cell BiologyDeep Dive

Concentration Gradients and Equilibrium

Part of Cell Transport — GCSE Biology

This deep dive covers Concentration Gradients and Equilibrium within Cell Transport for GCSE Biology. Diffusion, osmosis, active transport, factors affecting transport, surface area to volume ratio, and practical investigations It is section 4 of 18 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 4 of 18

Practice

18 questions

Recall

20 flashcards

🎯 Concentration Gradients and Equilibrium

What is a Concentration Gradient?

A concentration gradient exists when there is a difference in the concentration of particles between two areas. Particles naturally move from high concentration to low concentration until equilibrium is reached.

What happens at Equilibrium?

Particles are evenly distributed
No net movement occurs (but particles still move randomly)
The concentration gradient no longer exists
Dynamic equilibrium is maintained

Maintaining Gradients in Living Systems

Living organisms maintain concentration gradients by:

Blood circulation - removes substances from exchange surfaces
Ventilation - brings fresh air and removes stale air
Active transport - moves substances against gradients
Metabolism - uses up substances and produces waste

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 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).

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.