Functional analysis of the biomimetic silica precipitating activity of the R5 peptide from Cylindrotheca fusiformisElectronic supplementary information (ESI) available: HPLC and MALDI of peptides (11 pgs); EMs of silica particles (4 pgs); IR data (3 pgs); DLS data (1 pg) and mechanistic detail (1 pg). See http://www.rsc.org/suppdata/cc/b3/b309074d/