BEH.462/3. 962J Molecular Principles of Biomaterials Spring 2003 Control of crystal growth:' o Intracellular mineral deposition is controlled using microtubules and scaffolding proteins that allow the cell to pull on the vesicle, changing its shape and orientation during inorganic growth o Chemical deposition can also be controlled by nm-scale variation in spatial distribution or reactants E.g. sequentially-activated ion transporters lon flux Biosynthes Control of vesicle morphology SMT Scaffold Fig. 7.6 Pattern formation in intracellular biomineralization. B, biomineral; V, vesicle; MT, microtubule. Spatial control of chemical deposition Growth direction Lipid bilayer Growing mineral V equentially activated ion transporters (M Example: coccolith skeleton o Coccolithophorids: major group of calcifying algae o Production of lipid vesicles to confine calcite formation o Influx of calcium and carbonate ions o oriented nucleation of calcite crystals within enclosed vesicles o Control of crystal shape by active change in vesicle shape by cell's cytoskeleton Lecture 11-Inorganic Biomaterials 5of12BEH.462/3.962J Molecular Principles of Biomaterials Spring 2003 Lecture 11 – Inorganic Biomaterials 5 of 12 • Control of crystal growth:7 o Intracellular mineral deposition is controlled using microtubules and scaffolding proteins that allow the cell to pull on the vesicle, changing its shape and orientation during inorganic growth o Chemical deposition can also be controlled by nm-scale variation in spatial distribution or reactants ƒ E.g. sequentially-activated ion transporters (Mann, 2001) Growth direction Sequentially activated ion transporters Lipid bilayer Growing mineral Control of vesicle morphology: Spatial control of chemical deposition: • Example: coccolith skeleton o Coccolithophorids: major group of calcifying algae8 o Production of lipid vesicles to confine calcite formation o Influx of calcium and carbonate ions o oriented nucleation of calcite crystals within enclosed vesicles o Control of crystal shape by active change in vesicle shape by cell’s cytoskeleton