Diatom cell wall structures and components. Left, SEMs showing the diversity of diatom valve structures from different species. Scale bars a, k) 1 μm, b) 5 μm c, f) 10 μm d) 500 nm e, g, h, j, l) 2 μm, i) 50 μm. Center, diagram of a diatom cell during valve formation. Right, diagram of a dividing diatom cell highlighting major aspects of silicon’s interaction with the cell or valve formation (colored boxes) that are major focus areas of this study. Specific components are described in detail in the text.