Enzymes and substrate fit together at the active site to form a lock and key mechanism. This means a enzymes are not specific and work on a variety of substrates. b substrates work on enzymes, allowing them be be denatured. c the shape and size of the enzymes does not matter. d if they don't fit, it is the wrong substrate or the enzyme is denatured.

Answer 1

The correct interpretation of the lock and key mechanism is:

d: if they don't fit, it is the wrong substrate or the enzyme is denatured.

In the lock and key model, the enzyme (the "lock") and the substrate (the "key") must fit together specifically. If the substrate does not fit the active site of the enzyme, it either means that it is not the correct substrate for that enzyme or that the enzyme may be denatured (altered in shape such that it no longer functions properly). Enzymes are indeed specific to particular substrates based on their shapes.