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Re:Close-Up View of DNA Replication by dflock on Tuesday June 20, 2017 @12:19AM (#14592172)
> Are there just so many of them in the cytosol that through sheer numbers, there's enough random chance they'll just shuttle into place when the polymerase needs them?

Yes. Everything at that scale is very small, very close together and moving very, very fast.

This kind of thing is very common at the cellular level: have a receptor/channel/process/thing that only one precise 3d molecule can fit into - and then just wait.

As long as there's a process somewhere to make/acquire that molecule, then one will be along in a few nanoseconds or so, depending on the concentration. In the meantime the recipient will just wait.

In this way otherwise independent processes can regulate each other, and respond in a concentration dependant way to changing conditions without any central control.

Re:Close-Up View of DNA Replication by api on Tuesday June 20, 2017 @12:34AM (#14592224)
I always thought of it as a probability field of molecules.
Re:Close-Up View of DNA Replication by amelius on Tuesday June 20, 2017 @08:01AM (#14593842)
> have a receptor/channel/process/thing that only one precise 3d molecule can fit into

But what if the molecule has an unexpected "tail" attached to it? How to prevent the process from getting stuck?

Re:Close-Up View of DNA Replication by lurker456 on Tuesday June 20, 2017 @09:10AM (#14594306)
I imagine there are not many things with unexpected shapes at that level that aren't accounted for somehow. Anything that doesn't slot into it perfectly will get knocked away by collisions. Bad shapes do exist however (prions) and are a cause of diseases.
Re:Close-Up View of DNA Replication by AstralStorm on Tuesday June 20, 2017 @10:30AM (#14594896)
Generally bulky substrates are inefficient and require additional catalysts for binding. (Typically kinases.)

So something with an unexpected tail won't react. It will not occlude the receptor either because it won't bind with it reliably...

These things are very, very precise.