In several animations of biological processes (eg protein synthesis (go to frame 1.20mins), DNA replication, etc), molecules such as amino acids are shown heading straight to the replicating protein as if drawn by a magnet. As far as I know they move randomly. But still, translation occurs at a rate of about 15 amino acids/second and 75 ATP/second, so the rate of gobbling shown in the video clip is not off the mark.
I can think of two explanations:
1) The microscopic world is counter-intuitive. It is so frenetic that normal diffusion is enough to supply the hungry protein. The video simply doesn't show all the input molecules in order not to clutter the picture but essentially it is correct. However, amino acids are not small, and they are attached to the much larger tRNA, so they must be moving relatively slowly by Brownian motion.
2) There are additional helper proteins that concentrate or channel amino acids and ATPs in the vicinity of the ribosome or replicator. Never heard of these.
What is the real explanation?
Edit: To clarify, the question is not about the simulation side of things as such, such as how hard it is to actually make a true simulation. Most simulations, including weather prediction, involve a certain degree of approximations and simplifications. But in this case, there is something definitely untrue in the video clip, namely the molecules being attracted to the ribosome. As explained by a moderator, this means that it is not a true simulation but a "cartoon". So the question is: what would an ideal "non-cartoon" true simulation look like? Would the tRNA be diffusing in at a very fast rate, or are there helper proteins that, for example, tether tRNA in the vicinity of the ribosome? The moderators seem to indicate that diffusion is enough, but I would like to see a reasoned out answer with numbers that show this is the case.