BIO-MINERALIZATION Flashcards
Define the terms bio-mineralization, bio-minerals, biogenic minerals and biomimetic materials. Mention some extraordinary effects obtained in biogenic minerals.
Bio-mineralization: process where living organism convert elements obtained from its local environment into minerals, producing functional organic-inorganic bio-composites
Bio-minerals and biogenic minerals: minerals produced by a bio—mineralization process.
Biomimetic materials: man made minerals that mimic bio-minerals.
List/explain typical minerals that classify as bio-minerals. Which three cationic species are most frequently found in this type of minerals (hint –look up Weiner and Dove). What is the typical organic constituents in this type of minerals, and how are they integrated to the matrix?
Carbonates, hydroxides, oxides, metals…
Ca, Fe, Si
Proteins (often collagen) and chitin (glucose derivative)
Which two fundamental different processes of bio-mineralization are referred to in Weiner and Dove? Describe them briefly.
Biologically induced mineralization: Segregation of constituent to environment to react with species in environment. No control of type of bio-mineral formed.
Biologically controlled mineralization: The organism use cellular activities to direct nucleation, growth, morphology and final location of the mineral that is deposited. Mineralization processes occur in an isolated environment in various configurations.
(Extracellular mineralization, intercellular mineralization, controlled intracellular mineralization –no detailed required)
Describe the chiton radular teeth formation, include into your discussion the propagation of the growth from the initiation of the tooth to a fully developed tooth. What can we say about the material strength of these teeth? Explain. Hint –look up Weaver et al., 2010.
Less developed teeth: Interior: Poorly crystalline hydrated iron phosphate and chitin;
Exterior: Crystalline Fe3O4
What are magnetotactic bacteria and what is a magnetosome (look up Prozorov, 2015)?
Magnetotactic bacteria: Bacteria that responds to a magnetic field –diverse group of bacteria.
Magnetosome: Chains of magnetic nanoparticles inside a cell.
What is the so-called VerWey transition in magnetite? Discuss possible reasons why this transition is observed in magnetosome magnetite whereas it is so far not reported for colloidal synthesized magnetite nanoparticles.(Look up Prozorov, 2015.)
VerWey transition in magnetite: structural phase transition in Fe3O4 associated with changes in magnetic, electric and thermal properties.
What are glass sponges? What is their inorganic component, what is it produced from and what are special with their materials properties?
Glass-svamp – living organisms with their skeleton formed from small rods or long fibers of SiO2. They produce the skeleton from silicic acid, which they extract from sea water. Quality of SiO2 fibers may be of better quality with respect to transmit light and show better flexibility than those we produce in the laboratory (fiber optics).
Comment on Mother Nature’s ability to produce materials as we see in nacre, chiton teeth, glass sponges and magnetotactic bacteria relative to what we can do in the laboratory. What can be the reason for the superior quality of natural materials?
Many of mother nature’s nanostructures are better than similar man made materials. Many of these materials has been created by microscopic organism in a manner that has been perfected after millions of years. They are also utilizing bottom-up approach, but since they are so small themselves, they do it in a much more effective manner.
