Question about enzymes in the cell

 In those awesome intra-cell videos the 'particles'/'bits' go directly to their places as if they 'know' exactly where they are going.  For instance, a bit/particle made a 90 degree turn at the last moment into its destination / 'socket.  I was told that these bits/particles would not do this fast enough under Brownian motion to have a viable cell without [catalyzing, escorting] enzymes. (it's hard to believe anything would happen under Brownian motion)  Is there an escort that escorts those first enzymes that escort the bits/particles? How many layers are there in this escort service? In other words, how does the first enzyme 'know' to take bit/particle x exactly to place x? Is it by another enzyme that works on ('escorts') that first one to get it to go to place x? And what works on that second enzyme to get it to do what it does?-- a third enzyme?

Also, what's the percentage of those bits/particles (that build and tear down things in the cell) that are under Brownian motion and those under enzyme-escort motion?