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  1. Carole C Perry

Published Online: 19 MAY 2010

DOI: 10.1002/9780470015902.a0002079.pub2



How to Cite

Perry, C. C. 2010. Silica. eLS. .

Author Information

  1. Nottingham Trent University, Nottingham, UK

Publication History

  1. Published Online: 19 MAY 2010


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, c. 4–40°C. The mineral can be formed both intra- or extracellularly and specific biochemicals involved with mineral deposition include lipids, proteins (including heavily 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 although much still remains to be understood.

Key Concepts:

  • Silicon is an essential element for many if not all organisms.

  • A range of biomolecules/biopolymers are used to control and regulate silica precipitation in the natural environment.

  • The presence of biogenic silica in an organism confers functional properties on that organism which may include structural/mechanical support and/or defence against biotic or abiotic environmental stresses.

  • Much remains to be understood in respect of how the element is transported, concentrated and spatially organised within organisms as well as the effect the presence of the element/mineral has on other cellular functions.


  • silica;
  • silicic acid;
  • opal;
  • biosilicification;
  • silicatein;
  • long chain polyamines;
  • silaffin;
  • secondary plant cell wall;
  • diatoms;
  • sponges