Diffusion - Biology: AQA A Level

simple diffusion  There are 4 types of passive transport in total: simple diffusion, facilitated diffusion, filtration Facilitated diffusion is a type of passive transport that allows substances to cross membranes with the assistance of special transport proteins

There are 4 types of passive transport in total: simple diffusion, facilitated diffusion, filtration Simple diffusion is defined as the process in which a substance moves through a semipermeable membrane or in a solution without any help from transport proteins

Simple passive diffusion occurs when small molecules pass through the lipid bilayer of a cell membrane Facilitated diffusion depends on carrier proteins 2 Machinery requirements: As simple diffusion is passive, it requires no extra machinery For both facilitated diffusion and active transport, transmembrane