Cell membranes and transport
Cell membranes and transport

Every cell is surrounded by a cell membrane. This membrane controls what enters and leaves the cell, so substances such as oxygen, carbon dioxide, water and mineral ions must cross it.
Step-by-step lessons covering Edexcel GCSE Biology 1.4 Transport across cell membranes for Foundation and Higher tier. Each lesson breaks down 1.4.1 Transport into and out of cells and 1.4.2 Percentage gain and loss in osmosis, then works through exam-style questions in Paper 1 and Paper 2 format. Start with the foundational topics and build up to the higher-tier material.