A Level Biology Revision Lesson 62:
Simple (Passive) Diffusion.
Task 1. Check Where this Lesson fits into your Exam Specification!
Task 2. Watch the Revision Notes Lesson in Full.
Download the accompanying Revision Notes (A3 PDF)
Check Your Spec!
★ AQA Specification Reference: - 3.2.3 Transport across cell membranes. Movement across membranes occurs by: simple diffusion (involving limitations imposed by the nature of the phospholipid bilayer). Cells may be adapted for rapid transport across their internal or external membranes by an increase in surface area of, or by an increase in the number of protein channels and carrier molecules in, their membranes.
★ CIE Specification Reference: - 4 Cell membranes and transport. 4.2 Movement of substances into and out of cells: a) describe and explain the processes of diffusion.
★ Edexcel (Biology A – Salters-Nuffield) Specification Reference: - Topic 2: Genes and Health: 2.4 i) Understand what is meant by passive transport (diffusion).
★ Edexcel (Biology B) Specification Reference: - Topic 4: Exchange and Transport. 4.2 Cell transport mechanisms: ii Understand how passive transport is brought about by Diffusion.
★ OCR (Biology A) Specification Reference: - Module 2: Foundations in biology: 2.1.5 Biological membranes. (d) (i) the movement of molecules across membranes: To include diffusion and facilitated diffusion as passive methods.
★ OCR (Biology B) Specification Reference: - Module 2: Cells, chemicals for life, transport and gas exchange. (I) the movement of molecules across plasma membranes. To include diffusion and facilitated diffusion as passive methods of transport across membranes.
★ WJEC Specification Reference: -Core Concepts: 3. Cell membranes and transport. Overview: Cell membranes are essential in the control of the movement of substances into and out of the cell. They also play a vital role in cell recognition. (c) the following transport mechanisms: diffusion and factors affecting the rate of diffusion.