Figure 1: Thiol-functionalization of Thalassiosira weissflogii.
From: Functionalization of the living diatom Thalassiosira weissflogii with thiol moieties

Proposed hydrolysis of TMOS/MPTMS in the culture media, transport into diatom, subsequent co-condensation within the silica deposition vesicle and incorporation into the frustule.