Figure 5. (a) : ER geometry of the cutout enriched by the ribosomic belt. (b) : Surface grid enriched by the sphere where the RNA start concentration will be located. (c) : Clip plane of the tetrahedralized domain Ω . Subdomains of the tetrahedral volume element, i.e., part of the cell where the ER lumen is excluded. Subdomains: cytosol dark blue, ER surface cyan, the colored “blobs” are the web subdomains. The complete region Ω represents the computational