In this video, I go through all of the content required for the "Transport across cell membranes" section of the "Cells" unit for AQA A Level Biology. This includes: fluid-mosaic model of the cell membrane, simple diffusion, facilitated diffusion, active transport, co-transport and osmosis. The content crosses over with other exam boards too. I also go through some exam questions and their mark schemes. Please comment below if you have any questions. :)