Question

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

the denatured site
the amino acid site
the active site

Answer 1

The induced fit model means that the enzyme initially has a relatively *low* affinity for its substrate. The plain substrate and the plain enzyme by themselves do not fit so well with each other.

They fit a little bit, there is some weak association between the substrate and the enzyme - then that weak association with the substrate already slightly bound to the enzyme changes the enzyme's shape. The new shape fits the substrate much better than the unbound enzyme. Then the enzyme catalyses the reaction and they both dissociate on their merry way.

The question is about where on the enzyme the substrate binds. Think about where the substrate would have to bind for that model to hold.