F-FLT is taken up by the cell by both passive diffusion and facilitated transport by Na+-dependent carriers.
Since diffusion of the FSH receptors, much as diffusion of the cytoplasmic estrogen receptors will be restricted by the cell boundaries, even if cellular diffusion was very fast, we will use D R = 10−7 mm s−1, the diffusion coefficient for unhindered membrane diffusion [ 27- 29, 108], for all other receptors.
Regardless of the type of metabolic process they employ, the majority of bacteria are able to take in raw materials only in the form of relatively small molecules, which enter the cell by diffusion or through molecular channels in cell membranes.
After entering the cell by diffusion through the cell wall and transport through the PM, the drug should be released by esterases and chemical hydrolysis.
Specifically, the reaction substrate must be able to diffuse into the cells, and in the case of FACS the reaction product must be unable to leave the cell by diffusion or alternatively the product should be displayable on the cell surface to provide a fluorescent readout.
Physicochemical characteristics also influence the degree to which a drug is able to cross a barrier layer, and the route by which it does this; whether transcellular (across the cells -by diffusion, cells -byediffusionansport or transcarrier-mediatedellular-by diffusing transporthe tight junctiors between the cells.
However, in the case of cell imaging, heat diffusion is limited by the cell membrane.
The actual value of R is calculated at each step for each region of the virtual Petri dish (called "patch" in Netlogo) as the equilibrium between the quantity that is consumed by the cells and the constant diffusion of the substance from the surrounding culture medium.
Cellular aggregates also tend to agglomerate, and cells may die in regions where nutrients can no longer reach the cells by diffusion [17].
Most bacterial cells are detached by the flow when simply laid on agar; to overcome this problem, cells were insulated from the flow so that molecules reached the cells by diffusion through the thin agar pad.
