Unit 02 - Cell Structure and Function Concept Index A Tour of the CellMembrane Structure and Function 2.1 Cell Structure and Function 2.2 Cell Size 2.3 Plasma Membranes 2.4 Membrane Permeability 2.5 Membrane Transport 2.6 Facilitated Diffusion 2.7 Tonicity and Osmoregulation 2.8 Mechanisms of Transport 2.9 Cell Compartmentalization 2.10 Origins of Cell Compartmentalization