Silica

The element silicon (Si) is used by all living organisms either in molecular processes or in the formation of the mineral silica. The mineral is found in single cell organisms (e.g. radiolarian, diatoms, dinoflagellates and algae) through molluscs (e.g. limpets) to higher plants and primitive animals such as sponges. It is formed from an environment that is undersaturated with respect to Si and under conditions of around neutral pH and low temperature, ca. 4-40 °C. The mineral can be formed both intra- or extracellularly and specific biochemicals involved with mineral deposition include lipids, proteins (including posttranslationally modified proteins), long-change polyamines and carbohydrates. Knowledge of the complete genome for some species is providing opportunities to uncover the precise mechanisms of element uptake, transport, and deposition. The properties of biosilica (structure at the nano and micro scale, porosity, and surface chemistry) can be used to solve environmental, energy and health problems