List of Figures
Figure 1. Analogy between
the oxygen transfer model and the diffusion/reaction model. (A) Oxygen
transfer from the gas bubble into the cell’s cytoplasm and subsequent
reaction: (1) Transfer from the interior of the bubble to the
gas–liquid interface; (2) Movement across the gas–liquid interface;
(3) Diffusion through the relatively stagnant liquid film surrounding
the bubble; (4) Transport through the bulk liquid; (5) Diffusion through
the relatively stagnant liquid film surrounding the cells; (6) Movement
across the liquid–cell interface; (7) Transport through the cytoplasm
to the site where the reactions take place; (8) Biochemical reactions
involving oxygen consumption. Adapted from Blanch and
Clark10; (B) MP transport model in FISH: (1) MP
diffusion through the medium to the cell membrane; (2) Membrane uptake
of MP; (3) Cytoplasm diffusion within the cells to the nucleus; (4)
Reaction between the MP and the target RNA.
Figure 2. Schematic
representation of the MP’s diffusion in the bulk. l is the mean distance
between the cell-centres, where the maximum distance for a MP to
encounter a cell is l/2. This distance was further corrected by removing
the diameter of each cell-type, considering the cell in the centre of
the cube, in a vertical or horizontal orientation (for non-spherical
cells). Considering a three-dimensional movement of the MPs, the mean
square displacement (< r (n)2>) is the hypotenuse of the Pythagoras’s theorem for the
given geometric volume (r(n)2 = ((l
/2)2 + h2).
Figure 3. Variation of
the diffusional characteristic time (s) of a 10bp MP with the cellular
size of most bacterial and animal cells (in radius, µm) and bulk
cellular concentrations (cells/mL).
Figure
4 . Cellular membrane
differences between bacterial cells and animal cells. The schematic
representation is at scale considering the cell sizes displayed in Table
1. The bacterial cells are represented 5x times magnified.