Summary - transport across cell membrane Last document update:   ago

In AQA Biology, cell membrane transport methods include passive processes like diffusion, where molecules move from high to low concentration, facilitated diffusion aided by carrier or channel proteins, and osmosis, the movement of water across a semi-permeable membrane. Active transport, requiring ATP, moves substances against their concentration gradient through protein pumps. Endocytosis engulfs substances into vesicles formed from the membrane, while exocytosis expels substances from the cel...