Enzymes and substrate fit together at the active site to form a lock and key mechanism. This means

Question

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 answer is:

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

The lock and key model of enzyme action suggests that only specific substrates can fit into the active site of an enzyme, much like a key fits into a specific lock. If the substrate does not fit, it indicates that it is either the wrong substrate or that the enzyme has been denatured and its active site has changed shape.