In the induced-fit model of enzymes, a substrate associates itself with which part of an enzyme?

That would be the "active site".  There are three parts to the induced-fit model.  The substrate, the enzyme, and the active site.  The enzyme and the substrate form together like two puzzle pieces, and the active site is the space in between the two puzzle pieces.  It is still there when the enzyme and substrate have connected.  I hope I helped!  If I have wrong information, or you don't understand my analogy, please inform me so I can fix it.  :D  Thanks!