Living things must move materials into, out of, and within the cell. Substances can move across the cell membrane passively (i.e., osmosis and diffusion) or actively (i.e., active transport). This module focuses on the two types of cellular transport and assumes knowledge of cell membrane (components and functions, ie. Fluid Mosaic Model) has already been addressed. This module was developed by Teresa Ballou as part of a Virginia Commonwealth University STEM initiative sponsored by the Virginia Department of Education.